Trial Outcomes & Findings for Efficacy and Safety of Oral E5501 Plus Standard of Care for the Treatment of Thrombocytopenia in Adults With Chronic Immune Thrombocytopenia (Amendment 02) (NCT NCT01438840)

NCT ID: NCT01438840

Last Updated: 2018-02-05

Results Overview

The cumulative number of weeks of platelet response is defined as the total numbers of weeks in which the platelet count is greater than or equal to 50 x 10\^ 9/L during 6 months of treatment of core study in the absence of rescue therapy.

• Recruitment status: COMPLETED
• Study phase: PHASE3
• Target enrollment: 49 participants
• Primary outcome timeframe: Week 1 to Week 26
• Results posted on: 2018-02-05

Participant Flow

A total of 100 participants were screened in study. Of these 100 participants, 51 were screen failures and 49 were randomized into the study.

Participant milestones

Measure	Placebo (Core Study) Placebo was administered as 5 mg, 10 mg, 20 mg, 30 mg or 40 mg in a flexible dose design for 26 weeks. Placebo was administered orally at a starting dose of 20 mg, once daily. Afterwards the dose could be titrated up (maximum dose of 40 mg avatrombopag) or down (minimum dose of 5 mg avatrombopag) depending on the participant's response to the study drug; placebo titration was used to maintain the blind.	Avatrombopag (Core Study) Avatrombopag was administered orally as 5 mg, 10 mg, 20 mg, 30 mg, or 40 mg in a flexible dose design for 26 weeks. Participants received blinded therapy at a starting dose of 20 mg avatrombopag, one daily and they were allowed to have their dose titrated up (maximum dose of 40 mg avatrombopag) or down (minimum dose of 5 mg avatrombopag) depending on their response to study drug.	Avatrombopag (Extension Phase) Participants who met all the eligibility criteria requirements of extension phase and who discontinued the core study because of lack of treatment effect continued into the extension phase. Avatrombopag was administered to participants who entered extension phase, with a starting dose of 20 mg avatrombopag, once daily for 76 weeks and underwent dose titration.
Core Study STARTED	17	32	0
Core Study COMPLETED	1	22	0
Core Study NOT COMPLETED	16	10	0
Extension Phase STARTED	0	0	39
Extension Phase COMPLETED	0	0	29
Extension Phase NOT COMPLETED	0	0	10

Reasons for withdrawal

Measure	Placebo (Core Study) Placebo was administered as 5 mg, 10 mg, 20 mg, 30 mg or 40 mg in a flexible dose design for 26 weeks. Placebo was administered orally at a starting dose of 20 mg, once daily. Afterwards the dose could be titrated up (maximum dose of 40 mg avatrombopag) or down (minimum dose of 5 mg avatrombopag) depending on the participant's response to the study drug; placebo titration was used to maintain the blind.	Avatrombopag (Core Study) Avatrombopag was administered orally as 5 mg, 10 mg, 20 mg, 30 mg, or 40 mg in a flexible dose design for 26 weeks. Participants received blinded therapy at a starting dose of 20 mg avatrombopag, one daily and they were allowed to have their dose titrated up (maximum dose of 40 mg avatrombopag) or down (minimum dose of 5 mg avatrombopag) depending on their response to study drug.	Avatrombopag (Extension Phase) Participants who met all the eligibility criteria requirements of extension phase and who discontinued the core study because of lack of treatment effect continued into the extension phase. Avatrombopag was administered to participants who entered extension phase, with a starting dose of 20 mg avatrombopag, once daily for 76 weeks and underwent dose titration.
Core Study Adverse Event	0	3	0
Core Study Lack of Efficacy	15	7	0
Core Study Withdrawal of consent	1	0	0
Extension Phase Adverse Event	0	0	3
Extension Phase Lost to Follow-up	0	0	1
Extension Phase Withdrawal by Subject	0	0	3
Extension Phase Lack of Efficacy	0	0	2
Extension Phase Other	0	0	1

Baseline Characteristics

Efficacy and Safety of Oral E5501 Plus Standard of Care for the Treatment of Thrombocytopenia in Adults With Chronic Immune Thrombocytopenia (Amendment 02)

Baseline characteristics by cohort

Measure	Placebo (Core Study) n=17 Participants Placebo was administered as 5 mg, 10 mg, 20 mg, 30 mg or 40 mg in a flexible dose design for 26 weeks. Placebo was administered orally at a starting dose of 20 mg, once daily. Afterwards the dose could be titrated up (maximum dose of 40 mg avatrombopag) or down (minimum dose of 5 mg avatrombopag) depending on the participant's response to the study drug; placebo titration was used to maintain the blind.	Avatrombopag (Core Study) n=32 Participants Avatrombopag was administered orally as 5 mg, 10 mg, 20 mg, 30 mg, or 40 mg in a flexible dose design for 26 weeks. Participants received blinded therapy at a starting dose of 20 mg avatrombopag, one daily and they were allowed to have their dose titrated up (maximum dose of 40 mg avatrombopag) or down (minimum dose of 5 mg avatrombopag) depending on their response to study drug.	Total n=49 Participants Total of all reporting groups
Age, Continuous	41.2 Years STANDARD_DEVIATION 14.7 • n=5 Participants	46.4 Years STANDARD_DEVIATION 14.2 • n=7 Participants	44.6 Years STANDARD_DEVIATION 14.44 • n=5 Participants
Sex: Female, Male Female	8 Participants n=5 Participants	23 Participants n=7 Participants	31 Participants n=5 Participants
Sex: Female, Male Male	9 Participants n=5 Participants	9 Participants n=7 Participants	18 Participants n=5 Participants

PRIMARY outcome

Timeframe: Week 1 to Week 26

Population: Full Analysis Set (Core Study): All participants who were randomized into the study.

The cumulative number of weeks of platelet response is defined as the total numbers of weeks in which the platelet count is greater than or equal to 50 x 10^ 9/L during 6 months of treatment of core study in the absence of rescue therapy.

Outcome measures

Measure	Placebo (Core Study) n=17 Participants Placebo was administered as 5 mg, 10 mg, 20 mg, 30 mg or 40 mg in a flexible dose design for 26 weeks. Placebo was administered orally at a starting dose of 20 mg, once daily. Afterwards the dose could be titrated up (maximum dose of 40 mg avatrombopag) or down (minimum dose of 5 mg avatrombopag) depending on the participant's response to the study drug; placebo titration was used to maintain the blind.	Avatrombopag (Core Study) n=32 Participants Avatrombopag was administered orally as 5 mg, 10 mg, 20 mg, 30 mg, or 40 mg in a flexible dose design for 26 weeks. Participants received blinded therapy at a starting dose of 20 mg avatrombopag, one daily and they were allowed to have their dose titrated up (maximum dose of 40 mg avatrombopag) or down (minimum dose of 5 mg avatrombopag) depending on their response to study drug.
Number of Weeks With Platelet Count Greater Than or Equal to 50 x 10^9/L During 6-Month Treatment Period	0 Weeks Interval 0.0 to 2.0	12.4 Weeks Interval 0.0 to 25.0

SECONDARY outcome

Timeframe: Week 1 through Week 26

Population: Full Analysis Set (Core Study): All participants who were randomized into the study.

Only participants on concomitant ITP medications at baseline were included.

Outcome measures

Measure	Placebo (Core Study) n=7 Participants Placebo was administered as 5 mg, 10 mg, 20 mg, 30 mg or 40 mg in a flexible dose design for 26 weeks. Placebo was administered orally at a starting dose of 20 mg, once daily. Afterwards the dose could be titrated up (maximum dose of 40 mg avatrombopag) or down (minimum dose of 5 mg avatrombopag) depending on the participant's response to the study drug; placebo titration was used to maintain the blind.	Avatrombopag (Core Study) n=15 Participants Avatrombopag was administered orally as 5 mg, 10 mg, 20 mg, 30 mg, or 40 mg in a flexible dose design for 26 weeks. Participants received blinded therapy at a starting dose of 20 mg avatrombopag, one daily and they were allowed to have their dose titrated up (maximum dose of 40 mg avatrombopag) or down (minimum dose of 5 mg avatrombopag) depending on their response to study drug.
Number of Participants With a Reduction in Use of Concomitant Immune/Idiopathic Thrombocytopenic Purpura (ITP) Medication Yes	0 Participants	5 Participants
Number of Participants With a Reduction in Use of Concomitant Immune/Idiopathic Thrombocytopenic Purpura (ITP) Medication No	7 Participants	10 Participants

SECONDARY outcome

Timeframe: Week 1 (Day 8)

Population: Full Analysis Set (Core Study): All participants who were randomized into the study.

Participants with platelet response at Day 8 are defined as those who had a platelet count greater than or equal to 50 x 10^9/L at day 8 in the absence of rescue therapy on or before Day 8.

Outcome measures

Measure	Placebo (Core Study) n=17 Participants Placebo was administered as 5 mg, 10 mg, 20 mg, 30 mg or 40 mg in a flexible dose design for 26 weeks. Placebo was administered orally at a starting dose of 20 mg, once daily. Afterwards the dose could be titrated up (maximum dose of 40 mg avatrombopag) or down (minimum dose of 5 mg avatrombopag) depending on the participant's response to the study drug; placebo titration was used to maintain the blind.	Avatrombopag (Core Study) n=32 Participants Avatrombopag was administered orally as 5 mg, 10 mg, 20 mg, 30 mg, or 40 mg in a flexible dose design for 26 weeks. Participants received blinded therapy at a starting dose of 20 mg avatrombopag, one daily and they were allowed to have their dose titrated up (maximum dose of 40 mg avatrombopag) or down (minimum dose of 5 mg avatrombopag) depending on their response to study drug.
Number of Participants With Platelet Count Greater Than or Equal to 50 x 10^9/L at Day 8 Yes	0 Participants	21 Participants
Number of Participants With Platelet Count Greater Than or Equal to 50 x 10^9/L at Day 8 No	17 Participants	11 Participants

Adverse Events

Placebo (Core Study)

Serious events: 1 serious events

Other events: 10 other events

Deaths: 0 deaths

Avatrombopag (Core Study)

Serious events: 9 serious events

Other events: 31 other events

Deaths: 0 deaths

Avatrombopag (Extension Phase)

Serious events: 15 serious events

Other events: 45 other events

Deaths: 0 deaths

Serious adverse events

Measure	Placebo (Core Study) n=17 participants at risk Placebo was administered as 5 mg, 10 mg, 20 mg, 30 mg or 40 mg in a flexible dose design for 26 weeks. Placebo was administered orally at a starting dose of 20 mg, once daily. Afterwards the dose could be titrated up (maximum dose of 40 mg avatrombopag) or down (minimum dose of 5 mg avatrombopag) depending on the participant's response to the study drug; placebo titration was used to maintain the blind.	Avatrombopag (Core Study) n=32 participants at risk Avatrombopag was administered orally as 5 mg, 10 mg, 20 mg, 30 mg, or 40 mg in a flexible dose design for 26 weeks. Participants received blinded therapy at a starting dose of 20 mg avatrombopag, one daily and they were allowed to have their dose titrated up (maximum dose of 40 mg avatrombopag) or down (minimum dose of 5 mg avatrombopag) depending on their response to study drug.	Avatrombopag (Extension Phase) n=47 participants at risk Participants who met all eligibility criteria requirements of extension phase and who discontinued the core study because of lack of treatment effect continued into the extension phase. Avatrombopag was administered to participants who entered extension phase, with a starting dose of 20 mg avatrombopag, once daily for 76 weeks and underwent dose titration.
Blood and lymphatic system disorders Idiopathic thrombocytopenic purpura	5.9% 1/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	0.00% 0/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	0.00% 0/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Blood and lymphatic system disorders Thrombocytopenia	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	3.1% 1/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	6.4% 3/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Gastrointestinal disorders Food poisoning	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	3.1% 1/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	2.1% 1/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Gastrointestinal disorders Mouth haemorrhage	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	3.1% 1/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	2.1% 1/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Gastrointestinal disorders Nausea	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	3.1% 1/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	2.1% 1/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Gastrointestinal disorders Vomiting	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	6.2% 2/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	4.3% 2/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Gastrointestinal disorders Erosive duodenitis	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	0.00% 0/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	2.1% 1/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Gastrointestinal disorders Gastritis haemorrhagic	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	0.00% 0/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	2.1% 1/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Gastrointestinal disorders Gingival bleeding	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	0.00% 0/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	2.1% 1/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
General disorders Polyserositis	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	3.1% 1/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	2.1% 1/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Infections and infestations Urinary tract infection	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	3.1% 1/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	2.1% 1/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Investigations Platelet count decreased	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	3.1% 1/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	4.3% 2/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Investigations Alanine aminotransferase increased	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	0.00% 0/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	2.1% 1/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Investigations Aspartate aminotransferase increased	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	0.00% 0/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	2.1% 1/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Investigations Gamma-glutamyltransferase increased	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	0.00% 0/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	2.1% 1/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Nervous system disorders Cerebrovascular accident	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	3.1% 1/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	2.1% 1/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Nervous system disorders Headache	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	6.2% 2/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	4.3% 2/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Nervous system disorders Dizziness	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	0.00% 0/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	2.1% 1/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Musculoskeletal and connective tissue disorders Intervertebral disc disorder	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	0.00% 0/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	2.1% 1/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Chronic myelomonocytic leukaemia	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	0.00% 0/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	2.1% 1/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Reproductive system and breast disorders Uterine haemorrhage	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	3.1% 1/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	2.1% 1/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Respiratory, thoracic and mediastinal disorders Epistaxis	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	3.1% 1/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	2.1% 1/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Skin and subcutaneous tissue disorders Petechiae	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	3.1% 1/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	2.1% 1/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Vascular disorders Deep vein thrombosis	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	3.1% 1/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	2.1% 1/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Vascular disorders Jugular vein thrombosis	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	0.00% 0/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	2.1% 1/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.

Other adverse events

Measure	Placebo (Core Study) n=17 participants at risk Placebo was administered as 5 mg, 10 mg, 20 mg, 30 mg or 40 mg in a flexible dose design for 26 weeks. Placebo was administered orally at a starting dose of 20 mg, once daily. Afterwards the dose could be titrated up (maximum dose of 40 mg avatrombopag) or down (minimum dose of 5 mg avatrombopag) depending on the participant's response to the study drug; placebo titration was used to maintain the blind.	Avatrombopag (Core Study) n=32 participants at risk Avatrombopag was administered orally as 5 mg, 10 mg, 20 mg, 30 mg, or 40 mg in a flexible dose design for 26 weeks. Participants received blinded therapy at a starting dose of 20 mg avatrombopag, one daily and they were allowed to have their dose titrated up (maximum dose of 40 mg avatrombopag) or down (minimum dose of 5 mg avatrombopag) depending on their response to study drug.	Avatrombopag (Extension Phase) n=47 participants at risk Participants who met all eligibility criteria requirements of extension phase and who discontinued the core study because of lack of treatment effect continued into the extension phase. Avatrombopag was administered to participants who entered extension phase, with a starting dose of 20 mg avatrombopag, once daily for 76 weeks and underwent dose titration.
Blood and lymphatic system disorders Anaemia	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	6.2% 2/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	4.3% 2/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Blood and lymphatic system disorders Idiopathic thrombocytopenic purpura	5.9% 1/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	0.00% 0/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	0.00% 0/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Blood and lymphatic system disorders Iron deficiency anaemia	5.9% 1/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	0.00% 0/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	0.00% 0/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Blood and lymphatic system disorders Thrombocytopenia	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	6.2% 2/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	19.1% 9/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Gastrointestinal disorders Dyspepsia	5.9% 1/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	3.1% 1/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	2.1% 1/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Gastrointestinal disorders Gingival bleeding	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	12.5% 4/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	17.0% 8/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Gastrointestinal disorders Mouth Haemorrhage	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	9.4% 3/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	8.5% 4/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Gastrointestinal disorders Nausea	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	9.4% 3/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	6.4% 3/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Gastrointestinal disorders Vomiting	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	6.2% 2/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	4.3% 2/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
General disorders Fatigue	5.9% 1/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	12.5% 4/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	14.9% 7/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Infections and infestations Influenza	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	6.2% 2/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	8.5% 4/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Infections and infestations Nasopharyngitis	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	9.4% 3/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	10.6% 5/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Infections and infestations Pharyngitis	5.9% 1/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	0.00% 0/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	12.8% 6/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Infections and infestations Upper respiratory tract infection	5.9% 1/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	18.8% 6/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	23.4% 11/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Infections and infestations Urinary tract infection	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	3.1% 1/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	6.4% 3/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Injury, poisoning and procedural complications Contusion	23.5% 4/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	31.2% 10/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	40.4% 19/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Injury, poisoning and procedural complications Joint injury	5.9% 1/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	0.00% 0/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	0.00% 0/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Investigations Blood gastrin increased	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	6.2% 2/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	4.3% 2/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Investigations Blood urine present	5.9% 1/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	0.00% 0/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	0.00% 0/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Musculoskeletal and connective tissue disorders Arthralgia	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	12.5% 4/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	10.6% 5/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Musculoskeletal and connective tissue disorders Back pain	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	9.4% 3/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	8.5% 4/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Musculoskeletal and connective tissue disorders Pain in extremity	5.9% 1/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	3.1% 1/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	6.4% 3/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Nervous system disorders Dizziness	5.9% 1/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	0.00% 0/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	4.3% 2/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Nervous system disorders Headache	11.8% 2/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	37.5% 12/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	29.8% 14/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Nervous system disorders Somnolence	5.9% 1/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	0.00% 0/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	0.00% 0/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Psychiatric disorders Insomnia	5.9% 1/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	9.4% 3/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	6.4% 3/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Respiratory, thoracic and mediastinal disorders Cough	0.00% 0/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	6.2% 2/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	6.4% 3/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Respiratory, thoracic and mediastinal disorders Epistaxis	17.6% 3/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	12.5% 4/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	17.0% 8/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Skin and subcutaneous tissue disorders Petechiae	5.9% 1/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	12.5% 4/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	14.9% 7/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.
Vascular disorders Hypertension	5.9% 1/17 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	6.2% 2/32 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.	10.6% 5/47 • Core Study: up to 39 Weeks (including Screening, Titration, Treatment, Dose Taper, and Follow-up for those who did not enter the Extension Phase). Extension Phase: up to 104 weeks (including Conversion, Maintenance Period, Dose Taper, and Follow-up). Treatment emergent adverse events were collected. Core Study Safety Analysis Set (SAS): All participants who received at least 1 dose of study drug and had at least 1 postdose safety assessment. Extension Phase SAS: All participants who received at least 1 dose of avatrombopag (either Core or Extension Phase) and had a postdose safety assessment.

Additional Information

Eisai Inc.

Eisai Call Center

Phone: 888-422-4743

Results disclosure agreements

• Principal investigator is a sponsor employee
• Publication restrictions are in place

Restriction type: OTHER