Trial Outcomes & Findings for Study of Pegloticase (KRYSTEXXA®) Plus Methotrexate in Patients With Uncontrolled Gout (NCT NCT03635957)

NCT ID: NCT03635957

Last Updated: 2024-06-26

Results Overview

Serum uric acid (sUA \< 6 mg/dL) responders are defined as participants achieving and maintaining sUA \< 6 mg/dL for at least 80% of the time during Month 6 (Weeks 20, 22, and 24). Month 6 includes pre-infusion and post-infusion sUA assessments at Week 20, pre-infusion and post-infusion sUA assessments at Week 22, pre-infusion assessments at Week 24, and unscheduled sUA assessments between Week 20 and Week 24.

• Recruitment status: COMPLETED
• Study phase: PHASE4
• Target enrollment: 14 participants
• Primary outcome timeframe: Month 6 (Weeks 20, 22, and 24)
• Results posted on: 2024-06-26

Participant Flow

One participant was dosed with methotrexate (MTX) in the Run-In Period (MTX tolerance period) but was lost to follow up prior to the per protocol enrollment at Day 1. This participant was a screen failure but is included in the Run-in period data (including safety).

Participant milestones

Measure	All Participants Run-In Period: oral MTX at a dose of 15 mg weekly for 4 weeks prior to the first dose of pegloticase. Pegloticase + Immunomodulator (IMM) Period: pegloticase 8 mg administered intravenously (IV) every 2 weeks from Day 1 through the Week 50 Visit for a total of 26 infusions. MTX 15 mg weekly on the same day each week, within 1 to 3 days prior to each pegloticase infusion and one additional weekly dose after the last infusion.
Run-In Period STARTED	15
Run-In Period COMPLETED	14
Run-In Period NOT COMPLETED	1
Pegloticase + IMM Period STARTED	14
Pegloticase + IMM Period Completed Study at 24 Weeks-Amendment 1	1
Pegloticase + IMM Period Completed Study at 52 Weeks-Amendment 2	10
Pegloticase + IMM Period Discontinued Study Treatment Early	5
Pegloticase + IMM Period Had 3-Month Follow-up	7
Pegloticase + IMM Period Had 6-Month Follow-up	6
Pegloticase + IMM Period COMPLETED	11
Pegloticase + IMM Period NOT COMPLETED	3

Reasons for withdrawal

Measure	All Participants Run-In Period: oral MTX at a dose of 15 mg weekly for 4 weeks prior to the first dose of pegloticase. Pegloticase + Immunomodulator (IMM) Period: pegloticase 8 mg administered intravenously (IV) every 2 weeks from Day 1 through the Week 50 Visit for a total of 26 infusions. MTX 15 mg weekly on the same day each week, within 1 to 3 days prior to each pegloticase infusion and one additional weekly dose after the last infusion.
Run-In Period Lost to Follow-up	1
Pegloticase + IMM Period Lack of Efficacy	3

Baseline Characteristics

Study of Pegloticase (KRYSTEXXA®) Plus Methotrexate in Patients With Uncontrolled Gout

Baseline characteristics by cohort

Measure	Pegloticase With Methotrexate (MTX) n=14 Participants Run-In Period: oral MTX at a dose of 15 mg weekly for 4 weeks prior to the first dose of pegloticase. Pegloticase + IMM Period: pegloticase 8 mg administered IV every 2 weeks from Day 1 through the Week 50 Visit for a total of 26 infusions. MTX 15 mg weekly on the same day each week, within 1 to 3 days prior to each pegloticase infusion and one additional weekly dose after the last infusion.
Age, Continuous	49.3 years STANDARD_DEVIATION 8.66 • n=5 Participants
Sex: Female, Male Female	0 Participants n=5 Participants
Sex: Female, Male Male	14 Participants n=5 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	1 Participants n=5 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	13 Participants n=5 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=5 Participants
Race (NIH/OMB) Asian	2 Participants n=5 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants
Race (NIH/OMB) Black or African American	0 Participants n=5 Participants
Race (NIH/OMB) White	12 Participants n=5 Participants
Race (NIH/OMB) More than one race	0 Participants n=5 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants
Serum Uric Acid (sUA)	9.16 mg/dL STANDARD_DEVIATION 2.486 • n=5 Participants

PRIMARY outcome

Timeframe: Month 6 (Weeks 20, 22, and 24)

Population: Modified Intent to Treat Population: all enrolled participants who received at least 1 dose of pegloticase.

Serum uric acid (sUA < 6 mg/dL) responders are defined as participants achieving and maintaining sUA < 6 mg/dL for at least 80% of the time during Month 6 (Weeks 20, 22, and 24). Month 6 includes pre-infusion and post-infusion sUA assessments at Week 20, pre-infusion and post-infusion sUA assessments at Week 22, pre-infusion assessments at Week 24, and unscheduled sUA assessments between Week 20 and Week 24.

Outcome measures

Measure

Pegloticase With Methotrexate (MTX) n=14 Participants Run-In Period: oral MTX at a dose of 15 mg weekly for 4 weeks prior to the first dose of pegloticase. Pegloticase + IMM Period: pegloticase 8 mg administered IV every 2 weeks from Day 1 through the Week 50 Visit for a total of 26 infusions. MTX 15 mg weekly on the same day each week, within 1 to 3 days prior to each pegloticase infusion and one additional weekly dose after the last infusion.

Percentage of Serum Uric Acid (sUA < 6 mg/dL) Responders During Month 6

78.6 percentage of participants Interval 49.2 to 95.3

SECONDARY outcome

Timeframe: Month 3 (Weeks 10, 12, and 14)

Population: Modified Intent to Treat Population: all enrolled participants who received at least 1 dose of pegloticase.

Serum uric acid (sUA < 6 mg/dL) responders are defined as participants achieving and maintaining sUA < 6 mg/dL for at least 80% of the time during Month 3 (Weeks 10, 12, and 14). Month 3 includes pre-infusion and post-infusion sUA assessments at Week 10, pre-infusion and post-infusion sUA assessments at Week 12, pre-infusion assessments at Week 14, and unscheduled assessments between Week 10 and Week 14 pre-infusion.

Outcome measures

Measure

Pegloticase With Methotrexate (MTX) n=14 Participants Run-In Period: oral MTX at a dose of 15 mg weekly for 4 weeks prior to the first dose of pegloticase. Pegloticase + IMM Period: pegloticase 8 mg administered IV every 2 weeks from Day 1 through the Week 50 Visit for a total of 26 infusions. MTX 15 mg weekly on the same day each week, within 1 to 3 days prior to each pegloticase infusion and one additional weekly dose after the last infusion.

Percentage of Serum Uric Acid (sUA < 6 mg/dL) Responders During Month 3

78.6 percentage of participants Interval 49.2 to 95.3

SECONDARY outcome

Timeframe: Month 3 and Month 6 combined (Weeks 10, 12, 14, 20, 22, and 24)

Population: Modified Intent to Treat Population: all enrolled participants who received at least 1 dose of pegloticase.

Serum uric acid (sUA < 6 mg/dL) overall responders are defined as participants achieving and maintaining sUA < 6 mg/dL for at least 80% of the time during Month 3 and Month 6 (Weeks 10, 12, 14, 20, 22, and 24) combined. Participants with more than one sUA result in Month 3 and Month 6 are considered responders if a participant's weighted proportion of hours that sUA is < 6 mg/dL is greater than or equal to 80%. Participants with the proportion of hours less than 80% are counted as non-responders. Participants with only one value in Month 3 and Month 6 are considered overall responders if they are considered responders in both Month 3 and Month 6.

Outcome measures

Measure

Pegloticase With Methotrexate (MTX) n=14 Participants Run-In Period: oral MTX at a dose of 15 mg weekly for 4 weeks prior to the first dose of pegloticase. Pegloticase + IMM Period: pegloticase 8 mg administered IV every 2 weeks from Day 1 through the Week 50 Visit for a total of 26 infusions. MTX 15 mg weekly on the same day each week, within 1 to 3 days prior to each pegloticase infusion and one additional weekly dose after the last infusion.

Percentage of Serum Uric Acid (sUA < 6 mg/dL) Overall Responders

78.6 percentage of participants Interval 49.2 to 95.3

SECONDARY outcome

Timeframe: Month 3 (Weeks 10, 12, and 14)

Population: Modified Intent to Treat Population: all enrolled participants who received at least 1 dose of pegloticase.

Serum uric acid (sUA < 5 mg/dL) responders are defined as participants achieving and maintaining sUA < 5 mg/dL for at least 80% of the time during Month 3. Month 3 includes pre-infusion and post-infusion sUA assessments at Week 10, pre-infusion and post-infusion sUA assessments at Week 12, pre-infusion assessments at Week 14, and unscheduled assessments between Week 10 and Week 14 pre-infusion.

Outcome measures

Measure

Pegloticase With Methotrexate (MTX) n=14 Participants Run-In Period: oral MTX at a dose of 15 mg weekly for 4 weeks prior to the first dose of pegloticase. Pegloticase + IMM Period: pegloticase 8 mg administered IV every 2 weeks from Day 1 through the Week 50 Visit for a total of 26 infusions. MTX 15 mg weekly on the same day each week, within 1 to 3 days prior to each pegloticase infusion and one additional weekly dose after the last infusion.

Percentage of Serum Uric Acid (sUA < 5 mg/dL) Responders During Month 3

78.6 percentage of participants Interval 49.2 to 95.3

SECONDARY outcome

Timeframe: Month 6 (Weeks 20, 22, and 24)

Population: Modified Intent to Treat Population: all enrolled participants who received at least 1 dose of pegloticase.

Serum uric acid (sUA < 5 mg/dL) responders are defined as participants achieving and maintaining sUA < 5 mg/dL for at least 80% of the time during Month 6. Month 6 includes pre-infusion and post-infusion sUA assessments at Week 20, pre-infusion and post-infusion sUA assessments at Week 22, pre-infusion assessments at Week 24, and unscheduled sUA assessments between Week 20 and Week 24.

Outcome measures

Measure

Pegloticase With Methotrexate (MTX) n=14 Participants Run-In Period: oral MTX at a dose of 15 mg weekly for 4 weeks prior to the first dose of pegloticase. Pegloticase + IMM Period: pegloticase 8 mg administered IV every 2 weeks from Day 1 through the Week 50 Visit for a total of 26 infusions. MTX 15 mg weekly on the same day each week, within 1 to 3 days prior to each pegloticase infusion and one additional weekly dose after the last infusion.

Percentage of Serum Uric Acid (sUA < 5 mg/dL) Responders During Month 6

78.6 percentage of participants Interval 49.2 to 95.3

SECONDARY outcome

Timeframe: Month 3 and Month 6 combined (Weeks 10, 12, 14, 20, 22, and 24)

Population: Modified Intent to Treat Population: all enrolled participants who received at least 1 dose of pegloticase.

Serum uric acid (sUA < 5 mg/dL) overall responders are defined as participants achieving and maintaining sUA < 5 mg/dL for at least 80% of the time during Month 3 and Month 6 (Weeks 10, 12, 14, 20, 22, and 24) combined. Participants with more than one sUA result in Month 3 and Month 6 are considered responders if a participant's weighted proportion of hours that sUA is < 6 mg/dL is greater than or equal to 80%. Participants with the proportion of hours less than 80% are counted as non-responders. Participants with only one value in Month 3 and Month 6 are considered overall responders if they are considered responders in both Month 3 and Month 6.

Outcome measures

Measure

Pegloticase With Methotrexate (MTX) n=14 Participants Run-In Period: oral MTX at a dose of 15 mg weekly for 4 weeks prior to the first dose of pegloticase. Pegloticase + IMM Period: pegloticase 8 mg administered IV every 2 weeks from Day 1 through the Week 50 Visit for a total of 26 infusions. MTX 15 mg weekly on the same day each week, within 1 to 3 days prior to each pegloticase infusion and one additional weekly dose after the last infusion.

Percentage of Serum Uric Acid (sUA < 5 mg/dL) Overall Responders

78.6 percentage of participants Interval 49.2 to 95.3

SECONDARY outcome

Timeframe: Baseline (defined as the last measurement taken prior to the first infusion of pegloticase in the pegloticase + IMM period), Pre- and Post-Infusion at Weeks 14, 24, 36 and Week 52

Population: Modified Intent to Treat Population: all enrolled participants who received at least 1 dose of pegloticase. Participants with a measurement at given time point.

The mean change from baseline is based on observed values in participants remaining on treatment at given time point. For sUA values less than the lower limit of detection (up to 1.5 mg/dL), 0 is used in the analysis.

Outcome measures

Measure	Pegloticase With Methotrexate (MTX) n=14 Participants Run-In Period: oral MTX at a dose of 15 mg weekly for 4 weeks prior to the first dose of pegloticase. Pegloticase + IMM Period: pegloticase 8 mg administered IV every 2 weeks from Day 1 through the Week 50 Visit for a total of 26 infusions. MTX 15 mg weekly on the same day each week, within 1 to 3 days prior to each pegloticase infusion and one additional weekly dose after the last infusion.
Mean Change in sUA From Pegloticase Baseline to Weeks 14, 24, 36, 52 Change at Week 14 - pre-infusion	-9.27 mg/dL Standard Deviation 2.810
Mean Change in sUA From Pegloticase Baseline to Weeks 14, 24, 36, 52 Change at Week 14 - post-infusion	-9.31 mg/dL Standard Deviation 2.959
Mean Change in sUA From Pegloticase Baseline to Weeks 14, 24, 36, 52 Change at Week 24 - pre-infusion	-9.27 mg/dL Standard Deviation 2.810
Mean Change in sUA From Pegloticase Baseline to Weeks 14, 24, 36, 52 Change at Week 24 - post-infusion	-9.48 mg/dL Standard Deviation 4.135
Mean Change in sUA From Pegloticase Baseline to Weeks 14, 24, 36, 52 Change at Week 36 - pre-infusion	-8.13 mg/dL Standard Deviation 3.975
Mean Change in sUA From Pegloticase Baseline to Weeks 14, 24, 36, 52 Change at Week 36 - post-infusion	-9.41 mg/dL Standard Deviation 3.293
Mean Change in sUA From Pegloticase Baseline to Weeks 14, 24, 36, 52 Change at Week 52	-8.15 mg/dL Standard Deviation 4.086

Adverse Events

Run-In Period: MTX

Serious events: 0 serious events

Other events: 10 other events

Deaths: 0 deaths

Pegloticase + IMM Period: Pegloticase + MTX

Serious events: 1 serious events

Other events: 14 other events

Deaths: 0 deaths

Serious adverse events

Measure	Run-In Period: MTX n=15 participants at risk Run-In Period: oral MTX at a dose of 15 mg weekly for 4 weeks prior to the first dose of pegloticase.	Pegloticase + IMM Period: Pegloticase + MTX n=14 participants at risk Pegloticase + IMM Period: pegloticase 8 mg administered IV every 2 weeks from Day 1 through the Week 50 Visit for a total of 26 infusions. MTX 15 mg weekly on the same day each week, within 1 to 3 days prior to each pegloticase infusion and one additional weekly dose after the last infusion.
Infections and infestations Bacterial Sepsis	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.

Other adverse events

Measure	Run-In Period: MTX n=15 participants at risk Run-In Period: oral MTX at a dose of 15 mg weekly for 4 weeks prior to the first dose of pegloticase.	Pegloticase + IMM Period: Pegloticase + MTX n=14 participants at risk Pegloticase + IMM Period: pegloticase 8 mg administered IV every 2 weeks from Day 1 through the Week 50 Visit for a total of 26 infusions. MTX 15 mg weekly on the same day each week, within 1 to 3 days prior to each pegloticase infusion and one additional weekly dose after the last infusion.
Blood and lymphatic system disorders Leukopenia	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Blood and lymphatic system disorders Neutropenia	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Blood and lymphatic system disorders Lymphopenia	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Blood and lymphatic system disorders Splenomegaly	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Eye disorders Dry Eye	6.7% 1/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	0.00% 0/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Eye disorders Eye Irritation	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Gastrointestinal disorders Abdominal Discomfort	13.3% 2/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	0.00% 0/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Gastrointestinal disorders Dental Caries	6.7% 1/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	0.00% 0/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Gastrointestinal disorders Diarrhoea	6.7% 1/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	21.4% 3/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Gastrointestinal disorders Nausea	13.3% 2/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Gastrointestinal disorders Abdominal Pain	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Gastrointestinal disorders Constipation	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Gastrointestinal disorders Gastrooesophageal Reflux Disease	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Gastrointestinal disorders Tooth Impacted	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
General disorders Non-Cardiac Chest Pain	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Hepatobiliary disorders Cholecystitis Acute	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Hepatobiliary disorders Cholelithiasis	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Infections and infestations Chronic Sinusitis	6.7% 1/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Infections and infestations Nasopharyngitis	6.7% 1/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	21.4% 3/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Infections and infestations Carbuncle	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Infections and infestations Gastroenteritis Viral	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Infections and infestations Influenza	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Infections and infestations Sinusitis	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	14.3% 2/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Infections and infestations Upper Respiratory Tract Infection	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	21.4% 3/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Injury, poisoning and procedural complications Infusion Related Reaction	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Injury, poisoning and procedural complications Laceration	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Injury, poisoning and procedural complications Limb Injury	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Injury, poisoning and procedural complications Muscle Strain	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	21.4% 3/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Investigations Alanine Aminotransferase Increased	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Investigations Liver Function Test Increased	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Metabolism and nutrition disorders Gout	33.3% 5/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	92.9% 13/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Metabolism and nutrition disorders Hypercholesterolaemia	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Musculoskeletal and connective tissue disorders Arthralgia	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	21.4% 3/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Musculoskeletal and connective tissue disorders Osteoarthritis	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Musculoskeletal and connective tissue disorders Plantar Fasciitis	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Musculoskeletal and connective tissue disorders Tendonitis	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Nervous system disorders Carpal Tunnel Syndrome	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Nervous system disorders Dysgeusia	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Nervous system disorders Headache	6.7% 1/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Nervous system disorders Parosmia	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Renal and urinary disorders Dysuria	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Respiratory, thoracic and mediastinal disorders Cough	6.7% 1/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Skin and subcutaneous tissue disorders Pruritus	6.7% 1/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Skin and subcutaneous tissue disorders Rash Papular	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Skin and subcutaneous tissue disorders Skin Lesion	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	7.1% 1/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.
Vascular disorders Hypertension	0.00% 0/15 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.	14.3% 2/14 • From first dose of study drug through the end of treatment plus 30 days. Mean duration of MTX Treatment during the MTX Run-in Period was 23.0 days, and during the Pegloticase+IMM Period was 242.4 days. Mean duration of pegloticase treatment during the Pegloticase + IMM Period was 242.4 days. Treatment-emergent adverse events (TEAEs) are presented. The Intent to Treat population (all enrolled participants who took at least one dose of MTX) is used to present TEAEs for the run-in period. Modified Intent to Treat Population (all enrolled participants who received at least 1 dose of pegloticase) is used to present TEAEs for the Pegloticase + IMM Period.

Additional Information

Paul Peloso, MD

Horizon Therapeutics Ireland DAC

Phone: 866-479-6742

Email: clinicaltrials@horizontherapeutics.com

Results disclosure agreements

• Principal investigator is a sponsor employee Horizon requests that any Investigator/institution that plans on presenting or publishing results provide written notification of their request a minimum of 60 days prior to presentation or publication. The Sponsor may request that Confidential Information be deleted and/or the publication be postponed in order to protect the Sponsors' Intellectual Property rights.
• Publication restrictions are in place

Restriction type: OTHER