Trial Outcomes & Findings for A Study to Assess Whether Etrolizumab is a Safe and Efficacious Treatment for Participants With Moderately to Severely Active Crohn's Disease (NCT NCT02394028)

Last Updated: 2022-11-16

Results Overview

Clinical remission is defined as liquid/soft stool frequency (SF) mean daily score less than or equal (≤)3 and abdominal pain mean daily score ≤1, with no worsening in either subscore compared to baseline, averaged over the 7 days prior to visit.

Recruitment status

COMPLETED

Study phase

PHASE3

Target enrollment

1035 participants

Primary outcome timeframe

Week 14

Results posted on

2022-11-16

Participant Flow

At the time of study closure, a total of 1035 patients were randomized into the induction phase, enrolled sequentially across Cohorts 1, 2, and 3. The final sample size for the pivotal induction Cohort 3 was lower than the 496 patients planned per the final protocol due to the early closure of the study. Cohorts below are mutually exclusive.

A total of 1035 participants entered the study across induction cohorts 1-3, a subset of 487 patients moved into the maintenance phase of the study.

Participant milestones

Participant milestones
Measure	Placebo Cohort 1 Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Etrolizumab 105mg Cohort 1 Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Etrolizumab 210mg Cohort 1 Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one SC injection of etrolizumab (210 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Etrolizumab 105mg Cohort 2 Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking of the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Etrolizumab 210mg Cohort 2 Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (210 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking of the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Placebo Cohort 3 Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Etrolizumab 105mg Cohort 3 Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Etrolizumab 210mg Cohort 3 Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants will also receive one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Placebo/Placebo Participants who received placebo during the Induction Phase (from Cohorts 1 and 3) and achieved a CDAI-70 response at Week 14 underwent a sham randomization into the Maintenance Phase. Placebo responders from induction received blinded maintenance treatment with an SC injection of placebo once every 4 weeks (q4w) from Week 16 to Week 64.	Etrolizumab/Placebo Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who were re-randomized to this arm received blinded maintenance treatment with an SC injection of placebo q4w from Week 16 to Week 64.	Etrolizumab/Etrolizumab 105mg Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who were re-randomized to this arm received blinded maintenance treatment with an SC injection of etrolizumab (105 mg) q4w from Week 16 to Week 64.
Induction Phase STARTED	59	120	121	176	174	97	143	145	0	0	0
Induction Phase COMPLETED	52	104	108	141	145	80	118	114	0	0	0
Induction Phase NOT COMPLETED	7	16	13	35	29	17	25	31	0	0	0
Maintenance Phase STARTED	0	0	0	0	0	0	0	0	53	217	217
Maintenance Phase COMPLETED	0	0	0	0	0	0	0	0	41	175	165
Maintenance Phase NOT COMPLETED	0	0	0	0	0	0	0	0	12	42	52

Reasons for withdrawal

Reasons for withdrawal
Measure	Placebo Cohort 1 Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Etrolizumab 105mg Cohort 1 Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Etrolizumab 210mg Cohort 1 Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one SC injection of etrolizumab (210 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Etrolizumab 105mg Cohort 2 Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking of the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Etrolizumab 210mg Cohort 2 Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (210 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking of the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Placebo Cohort 3 Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Etrolizumab 105mg Cohort 3 Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Etrolizumab 210mg Cohort 3 Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants will also receive one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Placebo/Placebo Participants who received placebo during the Induction Phase (from Cohorts 1 and 3) and achieved a CDAI-70 response at Week 14 underwent a sham randomization into the Maintenance Phase. Placebo responders from induction received blinded maintenance treatment with an SC injection of placebo once every 4 weeks (q4w) from Week 16 to Week 64.	Etrolizumab/Placebo Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who were re-randomized to this arm received blinded maintenance treatment with an SC injection of placebo q4w from Week 16 to Week 64.	Etrolizumab/Etrolizumab 105mg Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who were re-randomized to this arm received blinded maintenance treatment with an SC injection of etrolizumab (105 mg) q4w from Week 16 to Week 64.
Induction Phase Adverse Event	2	4	1	2	5	2	0	0	0	0	0
Induction Phase Lack of Efficacy	3	6	2	17	14	8	17	23	0	0	0
Induction Phase Lost to Follow-up	1	0	0	1	0	0	1	0	0	0	0
Induction Phase Non-compliance	0	1	3	1	3	0	1	1	0	0	0
Induction Phase Physician Decision	0	0	1	4	0	2	1	0	0	0	0
Induction Phase Protocol Violation	0	2	0	3	0	1	1	0	0	0	0
Induction Phase Withdrawal by Subject	1	2	4	6	7	4	3	6	0	0	0
Induction Phase Early withdrawal and roll over to a different study	0	0	0	0	0	0	1	0	0	0	0
Induction Phase Sponsor decision	0	1	2	0	0	0	0	0	0	0	0
Induction Phase Technical reason	0	0	0	1	0	0	0	0	0	0	0
Induction Phase :ack of calculation	0	0	0	0	0	0	0	1	0	0	0
Maintenance Phase Protocol Violation	0	0	0	0	0	0	0	0	0	0	1
Maintenance Phase Physician Decision	0	0	0	0	0	0	0	0	1	3	2
Maintenance Phase Lack of Efficacy	0	0	0	0	0	0	0	0	7	25	33
Maintenance Phase Death	0	0	0	0	0	0	0	0	0	0	1
Maintenance Phase Adverse Event	0	0	0	0	0	0	0	0	1	1	3
Maintenance Phase Site closure	0	0	0	0	0	0	0	0	0	1	0
Maintenance Phase Withdrawal by Subject	0	0	0	0	0	0	0	0	3	12	12

Baseline Characteristics

Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Placebo Cohort 1 n=59 Participants Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Etrolizumab 105mg Cohort 1 n=120 Participants Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Etrolizumab 210mg Cohort 1 n=121 Participants Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one SC injection of etrolizumab (210 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Etrolizumab 105mg Cohort 2 n=176 Participants Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking of the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Etrolizumab 210mg Cohort 2 n=174 Participants Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (210 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking of the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Placebo Cohort 3 n=96 Participants Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Etrolizumab 105mg Cohort 3 n=143 Participants Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Etrolizumab 210mg Cohort 3 n=145 Participants Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants will also receive one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Maintenance Phase - Placebo Responders: Placebo n=53 Participants Participants who received placebo during the Induction Phase (from Cohorts 1 and 3) and achieved a CDAI-70 response at Week 14 underwent a sham randomization into the Maintenance Phase. Placebo responders from induction received blinded maintenance treatment with an SC injection of placebo once every 4 weeks (q4w) from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Placebo n=217 Participants Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of placebo q4w from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Etrolizumab 105 mg n=217 Participants Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of etrolizumab (105 mg) q4w from Week 16 to Week 64.	Total n=1521 Participants Total of all reporting groups
Age, Continuous Induction Phase	36.5 Years STANDARD_DEVIATION 12.7 • n=59 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase	38.9 Years STANDARD_DEVIATION 13.1 • n=120 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase	38.6 Years STANDARD_DEVIATION 13.4 • n=121 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase	38.4 Years STANDARD_DEVIATION 13.3 • n=176 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase	38.2 Years STANDARD_DEVIATION 13.2 • n=174 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase	37.1 Years STANDARD_DEVIATION 13.6 • n=96 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase	38.3 Years STANDARD_DEVIATION 13.4 • n=143 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase	36.5 Years STANDARD_DEVIATION 13.1 • n=145 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase	—	—	—	37.9 Years STANDARD_DEVIATION 13.2 • n=1034 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase
Age, Continuous Maintenance Phase	—	—	—	—	—	—	—	—	38.2 Years STANDARD_DEVIATION 13.3 • n=53 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase	37.9 Years STANDARD_DEVIATION 12.6 • n=217 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase	38.8 Years STANDARD_DEVIATION 12.9 • n=217 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase	38.3 Years STANDARD_DEVIATION 12.8 • n=487 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase
Sex: Female, Male Induction Phase · Female	31 Participants n=59 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	57 Participants n=120 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	68 Participants n=121 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	80 Participants n=176 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	80 Participants n=174 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	38 Participants n=96 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	69 Participants n=143 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	69 Participants n=145 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	—	—	—	492 Participants n=1034 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.
Sex: Female, Male Induction Phase · Male	28 Participants n=59 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	63 Participants n=120 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	53 Participants n=121 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	96 Participants n=176 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	94 Participants n=174 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	58 Participants n=96 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	74 Participants n=143 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	76 Participants n=145 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	—	—	—	542 Participants n=1034 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.
Sex: Female, Male Maintenance Phase · Female	—	—	—	—	—	—	—	—	24 Participants n=53 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	118 Participants n=217 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	98 Participants n=217 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	240 Participants n=487 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.
Sex: Female, Male Maintenance Phase · Male	—	—	—	—	—	—	—	—	29 Participants n=53 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	99 Participants n=217 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	119 Participants n=217 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	247 Participants n=487 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.
Ethnicity (NIH/OMB) Induction Phase · Hispanic or Latino	2 Participants n=59 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	5 Participants n=120 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	5 Participants n=121 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	7 Participants n=176 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	8 Participants n=174 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	15 Participants n=96 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	13 Participants n=143 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	7 Participants n=145 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	—	—	—	62 Participants n=1034 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.
Ethnicity (NIH/OMB) Induction Phase · Not Hispanic or Latino	53 Participants n=59 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	110 Participants n=120 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	113 Participants n=121 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	160 Participants n=176 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	154 Participants n=174 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	74 Participants n=96 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	126 Participants n=143 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	129 Participants n=145 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	—	—	—	919 Participants n=1034 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.
Ethnicity (NIH/OMB) Induction Phase · Unknown or Not Reported	4 Participants n=59 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	5 Participants n=120 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	3 Participants n=121 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	9 Participants n=176 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	12 Participants n=174 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	7 Participants n=96 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	4 Participants n=143 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	9 Participants n=145 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	—	—	—	53 Participants n=1034 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.
Ethnicity (NIH/OMB) Maintenance Phase · Hispanic or Latino	—	—	—	—	—	—	—	—	7 Participants n=53 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	10 Participants n=217 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	12 Participants n=217 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	29 Participants n=487 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.
Ethnicity (NIH/OMB) Maintenance Phase · Not Hispanic or Latino	—	—	—	—	—	—	—	—	41 Participants n=53 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	199 Participants n=217 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	197 Participants n=217 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	437 Participants n=487 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.
Ethnicity (NIH/OMB) Maintenance Phase · Unknown or Not Reported	—	—	—	—	—	—	—	—	5 Participants n=53 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	8 Participants n=217 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	8 Participants n=217 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	21 Participants n=487 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.
Race/Ethnicity, Customized Induction Phase · American Indian or Alaska Native	0 Participants n=59 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	0 Participants n=120 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	0 Participants n=121 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	0 Participants n=176 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	0 Participants n=174 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	1 Participants n=96 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	3 Participants n=143 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	0 Participants n=145 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	—	—	—	4 Participants n=1034 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.
Race/Ethnicity, Customized Induction Phase · Asian	5 Participants n=59 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	9 Participants n=120 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	7 Participants n=121 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	8 Participants n=176 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	14 Participants n=174 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	0 Participants n=96 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	4 Participants n=143 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	2 Participants n=145 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	—	—	—	49 Participants n=1034 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.
Race/Ethnicity, Customized Induction Phase · Black or African American	3 Participants n=59 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	5 Participants n=120 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	2 Participants n=121 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	1 Participants n=176 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	5 Participants n=174 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	6 Participants n=96 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	8 Participants n=143 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	2 Participants n=145 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	—	—	—	32 Participants n=1034 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.
Race/Ethnicity, Customized Induction Phase · White	46 Participants n=59 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	96 Participants n=120 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	104 Participants n=121 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	153 Participants n=176 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	141 Participants n=174 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	80 Participants n=96 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	117 Participants n=143 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	128 Participants n=145 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	—	—	—	865 Participants n=1034 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.
Race/Ethnicity, Customized Induction Phase · Other	1 Participants n=59 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	2 Participants n=120 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	2 Participants n=121 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	4 Participants n=176 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	2 Participants n=174 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	3 Participants n=96 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	3 Participants n=143 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	5 Participants n=145 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	—	—	—	22 Participants n=1034 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.
Race/Ethnicity, Customized Induction Phase · Multiple	0 Participants n=59 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	1 Participants n=120 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	1 Participants n=121 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	0 Participants n=176 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	0 Participants n=174 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	0 Participants n=96 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	0 Participants n=143 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	1 Participants n=145 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	—	—	—	3 Participants n=1034 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.
Race/Ethnicity, Customized Induction Phase · Unknown	4 Participants n=59 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	7 Participants n=120 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	5 Participants n=121 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	10 Participants n=176 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	12 Participants n=174 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	6 Participants n=96 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	8 Participants n=143 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	7 Participants n=145 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	—	—	—	59 Participants n=1034 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.
Race/Ethnicity, Customized Maintenance Phase · American Indian or Alaska Native	—	—	—	—	—	—	—	—	1 Participants n=53 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	0 Participants n=217 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	0 Participants n=217 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	1 Participants n=487 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.
Race/Ethnicity, Customized Maintenance Phase · Asian	—	—	—	—	—	—	—	—	0 Participants n=53 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	8 Participants n=217 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	11 Participants n=217 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	19 Participants n=487 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.
Race/Ethnicity, Customized Maintenance Phase · Black or African American	—	—	—	—	—	—	—	—	2 Participants n=53 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	5 Participants n=217 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	9 Participants n=217 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	16 Participants n=487 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.
Race/Ethnicity, Customized Maintenance Phase · White	—	—	—	—	—	—	—	—	45 Participants n=53 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	193 Participants n=217 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	182 Participants n=217 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	420 Participants n=487 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.
Race/Ethnicity, Customized Maintenance Phase · Other	—	—	—	—	—	—	—	—	2 Participants n=53 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	4 Participants n=217 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	7 Participants n=217 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	13 Participants n=487 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.
Race/Ethnicity, Customized Maintenance Phase · Multiple	—	—	—	—	—	—	—	—	0 Participants n=53 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	1 Participants n=217 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	1 Participants n=217 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	2 Participants n=487 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.
Race/Ethnicity, Customized Maintenance Phase · Unknown	—	—	—	—	—	—	—	—	3 Participants n=53 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	6 Participants n=217 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	7 Participants n=217 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.	16 Participants n=487 Participants • Induction Phase: Number analyzed is for participants in induction phase. Maintenance Phase: Number analyzed is for participants who entered the maintenance phase.

PRIMARY outcome

Timeframe: Week 14

Population: mITT - Modified Intent to Treat population: all patients randomized who received at least one dose of study drug, grouped under the randomized treatment arm. Results for Induction Phase Cohort 2 and 3 and Maintenance Phase are not presented.

Outcome measures

Outcome measures
Measure	Induction Phase - Cohort 1 (Exploratory): Placebo n=59 Participants Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 105 mg n=120 Participants Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 210 mg n=121 Participants Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one subcutaneous (SC) injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 105 mg Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking of the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 210 mg Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking for the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Placebo Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 105 mg Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 210 mg Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Maintenance Phase - Placebo Responders: Placebo Participants who received placebo during the Induction Phase (from Cohorts 1 and 3) and achieved a CDAI-70 response at Week 14 underwent a sham randomization into the Maintenance Phase. Placebo responders from induction received blinded maintenance treatment with an SC injection of placebo once every 4 weeks (q4w) from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Placebo Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of placebo q4w from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Etrolizumab 105 mg Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of etrolizumab (105 mg) q4w from Week 16 to Week 64.
Induction Phase: Cohort 1: Percentage of Participants With Clinical Remission at Week 14	11.9 Percentage of Particiapnts Interval 6.56 to 20.51	20.00 Percentage of Particiapnts Interval 14.69 to 26.64	27.3 Percentage of Particiapnts Interval 21.16 to 34.37	—	—	—	—	—	—	—	—

PRIMARY outcome

Timeframe: Week 14

Outcome measures

Outcome measures
Measure	Induction Phase - Cohort 1 (Exploratory): Placebo Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 105 mg Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 210 mg Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one subcutaneous (SC) injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 105 mg n=176 Participants Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking of the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 210 mg n=174 Participants Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking for the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Placebo n=96 Participants Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 105 mg n=143 Participants Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 210 mg n=145 Participants Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Maintenance Phase - Placebo Responders: Placebo Participants who received placebo during the Induction Phase (from Cohorts 1 and 3) and achieved a CDAI-70 response at Week 14 underwent a sham randomization into the Maintenance Phase. Placebo responders from induction received blinded maintenance treatment with an SC injection of placebo once every 4 weeks (q4w) from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Placebo Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of placebo q4w from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Etrolizumab 105 mg Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of etrolizumab (105 mg) q4w from Week 16 to Week 64.
Induction Phase: Cohort 2 and 3: Percentage of Participants With Clinical Remission at Week 14	—	—	—	29.5 Percentage of Particiapnts Interval 23.3 to 36.66	29.3 Percentage of Particiapnts Interval 23.05 to 36.46	29.2 Percentage of Particiapnts Interval 21.02 to 38.92	30.1 Percentage of Particiapnts Interval 23.16 to 38.03	33.1 Percentage of Particiapnts Interval 25.97 to 41.11	—	—	—

PRIMARY outcome

Timeframe: Week 14

Population: mITT. Results for Induction Phase Cohort 2 and 3 and Maintenance Phase are not presented.

Endoscopic improvement is defined as 50 percent (%) reduction from baseline in Simplified Endoscopic Index for Crohn's Disease (SES-CD) score.

Outcome measures

Outcome measures
Measure	Induction Phase - Cohort 1 (Exploratory): Placebo n=59 Participants Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 105 mg n=120 Participants Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 210 mg n=121 Participants Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one subcutaneous (SC) injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 105 mg Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking of the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 210 mg Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking for the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Placebo Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 105 mg Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 210 mg Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Maintenance Phase - Placebo Responders: Placebo Participants who received placebo during the Induction Phase (from Cohorts 1 and 3) and achieved a CDAI-70 response at Week 14 underwent a sham randomization into the Maintenance Phase. Placebo responders from induction received blinded maintenance treatment with an SC injection of placebo once every 4 weeks (q4w) from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Placebo Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of placebo q4w from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Etrolizumab 105 mg Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of etrolizumab (105 mg) q4w from Week 16 to Week 64.
Induction Phase: Cohort 1: Percentage of Participants With Endoscopic Improvement at Week 14	3.4 Percentage of Participants Interval -1.74 to 8.52	19.5 Percentage of Participants Interval 12.37 to 26.64	16.8 Percentage of Participants Interval 10.11 to 23.5	—	—	—	—	—	—	—	—

PRIMARY outcome

Timeframe: Week 14

Population: mITT. Results for Induction Phase Cohort 1 and Maintenance Phase are not presented.

Endoscopic improvement is defined as 50 percent (%) reduction from baseline in Simplified Endoscopic Index for Crohn's Disease (SES-CD) score.

Outcome measures

Outcome measures
Measure	Induction Phase - Cohort 1 (Exploratory): Placebo Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 105 mg Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 210 mg Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one subcutaneous (SC) injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 105 mg n=176 Participants Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking of the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 210 mg n=174 Participants Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking for the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Placebo n=96 Participants Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 105 mg n=143 Participants Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 210 mg n=145 Participants Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Maintenance Phase - Placebo Responders: Placebo Participants who received placebo during the Induction Phase (from Cohorts 1 and 3) and achieved a CDAI-70 response at Week 14 underwent a sham randomization into the Maintenance Phase. Placebo responders from induction received blinded maintenance treatment with an SC injection of placebo once every 4 weeks (q4w) from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Placebo Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of placebo q4w from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Etrolizumab 105 mg Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of etrolizumab (105 mg) q4w from Week 16 to Week 64.
Induction Phase: Cohort 2 and 3: Percentage of Participants With Endoscopic Improvement at Week 14	—	—	—	20.8 Percentage of Participants Interval 14.81 to 26.86	22.2 Percentage of Participants Interval 16.02 to 28.35	21.6 Percentage of Participants Interval 13.24 to 29.95	26.2 Percentage of Participants Interval 18.96 to 33.44	27.4 Percentage of Participants Interval 20.01 to 34.79	—	—	—

PRIMARY outcome

Timeframe: Baseline and Week 66

Population: mITT. Maintenance Phase Placebo/Placebo cohort is not reported since this is an exploratory population only. Results for the Induction phase populations for cohorts 1-3 are not presented

Outcome measures

Outcome measures
Measure	Induction Phase - Cohort 1 (Exploratory): Placebo Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 105 mg Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 210 mg Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one subcutaneous (SC) injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 105 mg Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking of the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 210 mg Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking for the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Placebo Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 105 mg Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 210 mg Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Maintenance Phase - Placebo Responders: Placebo Participants who received placebo during the Induction Phase (from Cohorts 1 and 3) and achieved a CDAI-70 response at Week 14 underwent a sham randomization into the Maintenance Phase. Placebo responders from induction received blinded maintenance treatment with an SC injection of placebo once every 4 weeks (q4w) from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Placebo n=217 Participants Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of placebo q4w from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Etrolizumab 105 mg n=217 Participants Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of etrolizumab (105 mg) q4w from Week 16 to Week 64.
Maintenance Phase: Percentage of Participants With Clinical Remission at Week 66	—	—	—	—	—	—	—	—	—	24.00 Percentage of Participants Interval 18.77 to 30.06	35.00 Percentage of Participants Interval 28.99 to 41.58

PRIMARY outcome

Timeframe: Week 66

Population: mITT. Maintenance Phase Placebo/Placebo cohort is not reported since this is an exploratory population only. Induction Phase population for cohorts 1-3 are not included

Endoscopic improvement is defined as 50% reduction from baseline in SES-CD score. Maintenance phase participants were evaluated.

Outcome measures

Outcome measures
Measure	Induction Phase - Cohort 1 (Exploratory): Placebo Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 105 mg Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 210 mg Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one subcutaneous (SC) injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 105 mg Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking of the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 210 mg Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking for the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Placebo Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 105 mg Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 210 mg Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Maintenance Phase - Placebo Responders: Placebo Participants who received placebo during the Induction Phase (from Cohorts 1 and 3) and achieved a CDAI-70 response at Week 14 underwent a sham randomization into the Maintenance Phase. Placebo responders from induction received blinded maintenance treatment with an SC injection of placebo once every 4 weeks (q4w) from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Placebo n=217 Participants Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of placebo q4w from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Etrolizumab 105 mg n=217 Participants Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of etrolizumab (105 mg) q4w from Week 16 to Week 64.
Maintenance Phase: Percentage of Participants With Endoscopic Improvement at Week 66	—	—	—	—	—	—	—	—	—	12.2 Percentage of Participants Interval 7.71 to 16.69	23.6 Percentage of Participants Interval 17.9 to 29.29

SECONDARY outcome

Timeframe: Week 6

Population: mITT. Results for Induction Phase Cohort 2 and 3 and Maintenance Phase are not presented.

Clinical remission is defined as SF mean daily score ≤3 and abdominal pain mean daily score ≤1, with no worsening in either subscore compared to baseline, averaged over the 7 days prior to visit.

Outcome measures

Outcome measures
Measure	Induction Phase - Cohort 1 (Exploratory): Placebo n=59 Participants Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 105 mg n=120 Participants Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 210 mg n=121 Participants Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one subcutaneous (SC) injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 105 mg Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking of the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 210 mg Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking for the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Placebo Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 105 mg Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 210 mg Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Maintenance Phase - Placebo Responders: Placebo Participants who received placebo during the Induction Phase (from Cohorts 1 and 3) and achieved a CDAI-70 response at Week 14 underwent a sham randomization into the Maintenance Phase. Placebo responders from induction received blinded maintenance treatment with an SC injection of placebo once every 4 weeks (q4w) from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Placebo Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of placebo q4w from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Etrolizumab 105 mg Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of etrolizumab (105 mg) q4w from Week 16 to Week 64.
Induction Phase: Cohort 1: Percentage of Participants With Clinical Remission at Week 6	5.1 Percentage of Participants Interval 2.05 to 12.06	15.0 Percentage of Participants Interval 10.41 to 21.13	24.8 Percentage of Participants Interval 18.93 to 31.75	—	—	—	—	—	—	—	—

SECONDARY outcome

Timeframe: Week 6

Population: mITT. Results for Induction Phase Cohort 1 and Maintenance Phase are not presented.

Clinical remission is defined as SF mean daily score ≤3 and abdominal pain mean daily score ≤1, with no worsening in either subscore compared to baseline, averaged over the 7 days prior to visit.

Outcome measures

Outcome measures
Measure	Induction Phase - Cohort 1 (Exploratory): Placebo Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 105 mg Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 210 mg Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one subcutaneous (SC) injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 105 mg n=176 Participants Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking of the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 210 mg n=174 Participants Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking for the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Placebo n=96 Participants Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 105 mg n=143 Participants Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 210 mg n=145 Participants Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Maintenance Phase - Placebo Responders: Placebo Participants who received placebo during the Induction Phase (from Cohorts 1 and 3) and achieved a CDAI-70 response at Week 14 underwent a sham randomization into the Maintenance Phase. Placebo responders from induction received blinded maintenance treatment with an SC injection of placebo once every 4 weeks (q4w) from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Placebo Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of placebo q4w from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Etrolizumab 105 mg Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of etrolizumab (105 mg) q4w from Week 16 to Week 64.
Induction Phase: Cohort 2 and 3: Percentage of Participants With Clinical Remission at Week 6	—	—	—	20.5 Percentage of Participants Interval 15.16 to 27.01	21.3 Percentage of Participants Interval 15.84 to 27.93	20.8 Percentage of Participants Interval 13.91 to 30.0	23.8 Percentage of Participants Interval 17.54 to 31.38	23.4 Percentage of Participants Interval 17.29 to 30.97	—	—	—

SECONDARY outcome

Timeframe: Week 14

Population: mITT. Results for Induction Phase Cohort 2 and 3 and Maintenance Phase are not presented.

Endoscopic Remission is defined as SES-CD total score \<=4 (\<=2 for ileal only patients), with no segment having a subcategory score \>1. SES-CD = Simple Endoscopic Score for Crohn's Disease. A composite of four assessments, each rated from 0 to 3: size of ulcers, proportion of the surface covered by ulcers, proportion of the surface with any other lesions, and presence of narrowings (stenosis). The SES-CD total score ranges from 0 to 60, a higher score indicates worse disease activity.

Outcome measures

Outcome measures
Measure	Induction Phase - Cohort 1 (Exploratory): Placebo n=59 Participants Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 105 mg n=120 Participants Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 210 mg n=121 Participants Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one subcutaneous (SC) injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 105 mg Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking of the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 210 mg Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking for the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Placebo Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 105 mg Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 210 mg Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Maintenance Phase - Placebo Responders: Placebo Participants who received placebo during the Induction Phase (from Cohorts 1 and 3) and achieved a CDAI-70 response at Week 14 underwent a sham randomization into the Maintenance Phase. Placebo responders from induction received blinded maintenance treatment with an SC injection of placebo once every 4 weeks (q4w) from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Placebo Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of placebo q4w from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Etrolizumab 105 mg Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of etrolizumab (105 mg) q4w from Week 16 to Week 64.
Induction Phase: Cohort 1: Percentage of Participants With SES-CD Score ≤4 (≤2 for Ileal Participants), With No Segment Having a Subcategory Score Greater Than (>)1, at Week 14	1.7 Percentage of Participants Interval -2.4 to 5.79	13.8 Percentage of Participants Interval 7.53 to 20.14	8.3 Percentage of Participants Interval 3.29 to 13.24	—	—	—	—	—	—	—	—

SECONDARY outcome

Timeframe: Week 14

Population: mITT. Results for Induction Phase Cohort 1 and Maintenance Phase are not presented.

Outcome measures

Outcome measures
Measure	Induction Phase - Cohort 1 (Exploratory): Placebo Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 105 mg Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 210 mg Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one subcutaneous (SC) injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 105 mg n=176 Participants Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking of the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 210 mg n=174 Participants Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking for the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Placebo n=96 Participants Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 105 mg n=143 Participants Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 210 mg n=145 Participants Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Maintenance Phase - Placebo Responders: Placebo Participants who received placebo during the Induction Phase (from Cohorts 1 and 3) and achieved a CDAI-70 response at Week 14 underwent a sham randomization into the Maintenance Phase. Placebo responders from induction received blinded maintenance treatment with an SC injection of placebo once every 4 weeks (q4w) from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Placebo Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of placebo q4w from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Etrolizumab 105 mg Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of etrolizumab (105 mg) q4w from Week 16 to Week 64.
Induction Phase: Cohort 2 and 3: Percentage of Participants With SES-CD Score ≤4 (≤2 for Ileal Participants), With No Segment Having a Subcategory Score Greater Than (>)1, at Week 14	—	—	—	9.9 Percentage of Participants Interval 5.43 to 14.42	12.3 Percentage of Participants Interval 5.43 to 14.42	8.7 Percentage of Participants Interval 2.84 to 14.52	10.2 Percentage of Participants Interval 5.15 to 15.27	15.3 Percentage of Participants Interval 9.33 to 21.29	—	—	—

SECONDARY outcome

Timeframe: Baseline and Week 14

Population: mITT. Data evaluable participants are included. Results for Induction Phase Cohort 2 and 3 and Maintenance Phase are not presented. Only patients with a baseline score and at least one post-baseline score are included in the analysis

CD-PRO/SS: Crohn's Disease Patient Reported Outcomes Signs and Symptoms. For each item, the score is taken as the average across 4-7 days eDiary data within a 9 day window from visit, else the score is considered missing. The CD-PRO/SS Bowel domain is a total score summed across 3 items and ranges from 0 - 16. The Functional domain score is a total score summed across 3 items and ranges from 0 - 12. A higher CD-PRO/SS score indicates worse quality of life. Participants are included in the analysis if they have both Baseline and at least one post-baseline score available.

Outcome measures

Outcome measures
Measure	Induction Phase - Cohort 1 (Exploratory): Placebo n=46 Participants Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 105 mg n=76 Participants Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 210 mg n=87 Participants Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one subcutaneous (SC) injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 105 mg Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking of the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 210 mg Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking for the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Placebo Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 105 mg Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 210 mg Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Maintenance Phase - Placebo Responders: Placebo Participants who received placebo during the Induction Phase (from Cohorts 1 and 3) and achieved a CDAI-70 response at Week 14 underwent a sham randomization into the Maintenance Phase. Placebo responders from induction received blinded maintenance treatment with an SC injection of placebo once every 4 weeks (q4w) from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Placebo Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of placebo q4w from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Etrolizumab 105 mg Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of etrolizumab (105 mg) q4w from Week 16 to Week 64.
Induction Phase: Cohort 1: Change From Baseline in Crohn's Disease-Patient-Reported Outcome Signs and Symptoms (CD-PRO/SS) Score at Week 14 CD-PRO/SS Functional Domain Score	-0.7 scores on a scale Standard Error 0.4	-1.4 scores on a scale Standard Error 0.3	-1.6 scores on a scale Standard Error 0.3	—	—	—	—	—	—	—	—
Induction Phase: Cohort 1: Change From Baseline in Crohn's Disease-Patient-Reported Outcome Signs and Symptoms (CD-PRO/SS) Score at Week 14 CD-PRO/SS Bowel Domain Score	-0.7 scores on a scale Standard Error 0.4	-1.5 scores on a scale Standard Error 0.3	-1.3 scores on a scale Standard Error 0.3	—	—	—	—	—	—	—	—

SECONDARY outcome

Timeframe: Baseline and Week 14

Population: mITT. Data evaluable participants are included. Results for Induction Phase Cohort 1 and Maintenance Phase are not presented. Only patients with a baseline score and at least one post-baseline score are included in the analysis

Outcome measures

Outcome measures
Measure	Induction Phase - Cohort 1 (Exploratory): Placebo Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 105 mg Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 210 mg n=87 Participants Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one subcutaneous (SC) injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 105 mg n=132 Participants Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking of the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 210 mg n=137 Participants Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking for the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Placebo n=91 Participants Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 105 mg n=138 Participants Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 210 mg n=137 Participants Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Maintenance Phase - Placebo Responders: Placebo Participants who received placebo during the Induction Phase (from Cohorts 1 and 3) and achieved a CDAI-70 response at Week 14 underwent a sham randomization into the Maintenance Phase. Placebo responders from induction received blinded maintenance treatment with an SC injection of placebo once every 4 weeks (q4w) from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Placebo Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of placebo q4w from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Etrolizumab 105 mg Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of etrolizumab (105 mg) q4w from Week 16 to Week 64.
Induction Phase: Cohort 2 and 3: Change From Baseline in Crohn's Disease-Patient-Reported Outcome Signs and Symptoms (CD-PRO/SS) Score at Week 14 CD-PRO/SS Functional Domain Score	—	—	—	-2.0 scores on a scale Standard Error 0.2	-2.3 scores on a scale Standard Error 0.2	-1.9 scores on a scale Standard Error 0.3	-1.6 scores on a scale Standard Error 0.2	-1.9 scores on a scale Standard Error 0.2	—	—	—
Induction Phase: Cohort 2 and 3: Change From Baseline in Crohn's Disease-Patient-Reported Outcome Signs and Symptoms (CD-PRO/SS) Score at Week 14 CD-PRO/SS Bowel Domain Score	—	—	—	-2.3 scores on a scale Standard Error 0.3	-2.2 scores on a scale Standard Error 0.3	-2.0 scores on a scale Standard Error 0.3	-2.0 scores on a scale Standard Error 0.3	-2.3 scores on a scale Standard Error 0.3	—	—	—

SECONDARY outcome

Timeframe: Baseline, Weeks 14 and 66

Population: mITT. Data evaluable participants are included. Placebo/Placebo Maintenance Cohort is not reported since this is an exploratory population only. Results for Induction Phase is not presented.

Outcome measures

Outcome measures
Measure	Induction Phase - Cohort 1 (Exploratory): Placebo Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 105 mg Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 210 mg Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one subcutaneous (SC) injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 105 mg Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking of the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 210 mg Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking for the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Placebo Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 105 mg Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 210 mg Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Maintenance Phase - Placebo Responders: Placebo Participants who received placebo during the Induction Phase (from Cohorts 1 and 3) and achieved a CDAI-70 response at Week 14 underwent a sham randomization into the Maintenance Phase. Placebo responders from induction received blinded maintenance treatment with an SC injection of placebo once every 4 weeks (q4w) from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Placebo n=97 Participants Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of placebo q4w from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Etrolizumab 105 mg n=108 Participants Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of etrolizumab (105 mg) q4w from Week 16 to Week 64.
Maintenance Phase: Percentage of Participants With Clinical Remission at Week 66, Among Those Who Achieved Clinical Remission at Week 14	—	—	—	—	—	—	—	—	—	39.2 Percentage of Participants Interval 30.05 to 49.12	56.5 Percentage of Participants Interval 47.07 to 65.45

SECONDARY outcome

Timeframe: Baseline and Week 66

Population: mITT. Maintenance Phase Cohorts only. Placebo/Placebo Maintenance Cohort is not reported since this is an exploratory population only. Only patients receiving oral corticosteroids at Baseline are included in the analysis

Outcome measures

Outcome measures
Measure	Induction Phase - Cohort 1 (Exploratory): Placebo Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 105 mg Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 210 mg Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one subcutaneous (SC) injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 105 mg Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking of the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 210 mg Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking for the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Placebo Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 105 mg Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 210 mg Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Maintenance Phase - Placebo Responders: Placebo Participants who received placebo during the Induction Phase (from Cohorts 1 and 3) and achieved a CDAI-70 response at Week 14 underwent a sham randomization into the Maintenance Phase. Placebo responders from induction received blinded maintenance treatment with an SC injection of placebo once every 4 weeks (q4w) from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Placebo n=91 Participants Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of placebo q4w from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Etrolizumab 105 mg n=93 Participants Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of etrolizumab (105 mg) q4w from Week 16 to Week 64.
Maintenance Phase: Percentage of Participants With Corticosteroid-Free Clinical Remission at Week 66, Among Those Who Were Receiving Corticosteroids at Baseline	—	—	—	—	—	—	—	—	—	11.0 Percentage of Participants Interval 6.08 to 19.06	29.0 Percentage of Participants Interval 20.79 to 38.94

SECONDARY outcome

Timeframe: Baseline, Weeks 14 and 66

Population: mITT. Only patients achieving endoscopic improvement at Week 14 are included in the analysis. Results for Induction Phase Cohort is not presented.

Endoscopic improvement is defined as 50% reduction from baseline in SES-CD score. Induction Phase Cohorts are not included

Outcome measures

Outcome measures
Measure	Induction Phase - Cohort 1 (Exploratory): Placebo Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 105 mg Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 210 mg Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one subcutaneous (SC) injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 105 mg Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking of the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 210 mg Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking for the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Placebo Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 105 mg Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 210 mg Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Maintenance Phase - Placebo Responders: Placebo Participants who received placebo during the Induction Phase (from Cohorts 1 and 3) and achieved a CDAI-70 response at Week 14 underwent a sham randomization into the Maintenance Phase. Placebo responders from induction received blinded maintenance treatment with an SC injection of placebo once every 4 weeks (q4w) from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Placebo n=58 Participants Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of placebo q4w from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Etrolizumab 105 mg n=72 Participants Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of etrolizumab (105 mg) q4w from Week 16 to Week 64.
Maintenance Phase: Percentage of Participants With Endoscopic Improvement at Week 66 Among Participants Who Achieved Endoscopic Improvement at Week 14	—	—	—	—	—	—	—	—	—	25.3 Percentage of Participants Interval 14.14 to 36.44	37.5 Percentage of Participants Interval 26.28 to 48.72

SECONDARY outcome

Timeframe: Week 66

Population: mITT. Maintenance Phase Placebo/Placebo are is not reported since this is an exploratory population only. Results for Induction Phase is not presented.

Outcome measures

Outcome measures
Measure	Induction Phase - Cohort 1 (Exploratory): Placebo Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 105 mg Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 210 mg Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one subcutaneous (SC) injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 105 mg Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking of the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 210 mg Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking for the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Placebo Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 105 mg Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 210 mg Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Maintenance Phase - Placebo Responders: Placebo Participants who received placebo during the Induction Phase (from Cohorts 1 and 3) and achieved a CDAI-70 response at Week 14 underwent a sham randomization into the Maintenance Phase. Placebo responders from induction received blinded maintenance treatment with an SC injection of placebo once every 4 weeks (q4w) from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Placebo n=217 Participants Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of placebo q4w from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Etrolizumab 105 mg n=217 Participants Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of etrolizumab (105 mg) q4w from Week 16 to Week 64.
Maintenance Phase: Percentage of Participants With SES-CD Score ≤4 (≤2 for Ileal Participants), With No Segment Having a Subcategory Score >1, at Week 66	—	—	—	—	—	—	—	—	—	5.9 Percentage of Participants Interval 2.62 to 9.18	12.1 Percentage of Participants Interval 7.61 to 16.54

SECONDARY outcome

Timeframe: Week 14 up to Week 66 (assessed at Weeks 24, 28, 32, 44, 56, and 66)

Population: mITT. Maintenance Phase Placebo/Placebo arm is not reported since this is an exploratory population only. Results for Induction Phase is not presented.

Clinical remission is defined as SF mean daily score ≤3 and abdominal pain mean daily score ≤1, with no worsening in either subscore compared to baseline, averaged over the 7 days prior to visit. Durable clinical remission was defined as clinical remission at ≥4 of the 6 in-clinic assessment visits conducted during the Maintenance Phase at Weeks 24, 28, 32, 44, 56, and 66. Induction Phase Cohorts are not included

Outcome measures

Outcome measures
Measure	Induction Phase - Cohort 1 (Exploratory): Placebo Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 105 mg Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 210 mg Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one subcutaneous (SC) injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 105 mg Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking of the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 210 mg Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking for the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Placebo Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 105 mg Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 210 mg Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Maintenance Phase - Placebo Responders: Placebo Participants who received placebo during the Induction Phase (from Cohorts 1 and 3) and achieved a CDAI-70 response at Week 14 underwent a sham randomization into the Maintenance Phase. Placebo responders from induction received blinded maintenance treatment with an SC injection of placebo once every 4 weeks (q4w) from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Placebo n=217 Participants Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of placebo q4w from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Etrolizumab 105 mg n=217 Participants Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of etrolizumab (105 mg) q4w from Week 16 to Week 64.
Maintenance Phase: Percentage of Participants With Durable Clinical Remission	—	—	—	—	—	—	—	—	—	19.8 Percentage of Participants Interval 15.06 to 25.62	30.9 Percentage of Participants Interval 25.11 to 37.31

SECONDARY outcome

Timeframe: Baseline and from Week 14 up to Week 66

Population: mITT. Maintenance Phase Placebo/Placebo is arm is not reported since this is an exploratory population only. Results for Induction Phase is not presented. Only patients receiving oral corticosteroids at Baseline are included in the analysis'

Clinical remission is defined as SF mean daily score ≤3 and abdominal pain mean daily score ≤1, with no worsening in either subscore compared to baseline, averaged over the 7 days prior to visit. Percentage of participants with clinical remission who will be off corticosteroids for at least 24 weeks prior to Week 66 will be reported. Induction Phase Cohorts are not included

Outcome measures

Outcome measures
Measure	Induction Phase - Cohort 1 (Exploratory): Placebo Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 105 mg Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 1 (Exploratory): Etrolizumab 210 mg Cohort 1 enrolled participants first before Cohorts 2 and 3 in order to conduct an exploratory analysis on induction data. Participants randomized to this arm received one subcutaneous (SC) injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12. 90%CI	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 105 mg Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking of the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 2 (Open-Label): Etrolizumab 210 mg Cohort 2 enrolled participants after Cohort 1 and was considered a "feeder" cohort to help achieve the necessary sample size for the Maintenance Phase. Participants randomized to this arm received one SC injection of open-label etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking for the dose of etrolizumab, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Placebo Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received two SC injections of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12 (and one SC injection of etrolizumab-matching placebo at Week 2) during the 14-week Induction Phase, in order to preserve the masking.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 105 mg Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (105 mg) at Weeks 0, 4, 8, 12 and one SC injection of etrolizumab-matching placebo at Week 2 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Induction Phase - Cohort 3 (Pivotal): Etrolizumab 210 mg Cohort 3 was the last to enroll participants (after Cohort 2) and was the pivotal cohort for the Induction Phase. Participants randomized to this arm received one SC injection of etrolizumab (210 mg) at Weeks 0, 2, 4, 8, and 12 during the 14-week Induction Phase. In order to preserve the masking, participants also received one SC injection of etrolizumab-matching placebo at Weeks 0, 4, 8, and 12.	Maintenance Phase - Placebo Responders: Placebo Participants who received placebo during the Induction Phase (from Cohorts 1 and 3) and achieved a CDAI-70 response at Week 14 underwent a sham randomization into the Maintenance Phase. Placebo responders from induction received blinded maintenance treatment with an SC injection of placebo once every 4 weeks (q4w) from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Placebo n=91 Participants Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of placebo q4w from Week 16 to Week 64.	Maintenance Phase - Etrolizumab Responders: Etrolizumab 105 mg n=93 Participants Participants who received etrolizumab during the Induction Phase (from Cohorts 1-3) and achieved a CDAI-70 response at Week 14 without the use of rescue therapy were re-randomized into the Maintenance Phase. Etrolizumab responders from induction who are re-randomized to this arm received blinded maintenance treatment with an SC injection of etrolizumab (105 mg) q4w from Week 16 to Week 64.
Maintenance Phase: Percentage of Participants With Corticosteroid-Free Clinical Remission for at Least 24 Weeks at Week 66, Among Those Who Were Receiving Corticosteroids at Baseline	—	—	—	—	—	—	—	—	—	9.9 Percentage of Participants Interval 5.29 to 17.74	25.8 Percentage of Participants Interval 18.0 to 35.53

SECONDARY outcome

Timeframe: Baseline and Week 66

Population: mITT. Data evaluable participants are included. Only patients with a baseline score and at least one post-baseline score are included in the analysis. The Maintenance Phase Placebo/Placebo arm is not reported since this is an exploratory population only. Results for Induction Phase is not presented.