A Study of Rilzabrutinib in Adult Patients With Immune Thrombocytopenia (ITP)

An Adaptive, Open-Label, Dose-Finding, Phase 1/2 Study Investigating the Safety, Pharmacokinetics, and Clinical Activity of PRN1008, an Oral BTK Inhibitor, in Patients With Relapsed Immune Thrombocytopenia

Status

Completed

Phases

Phase 2

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT03395210

Enrollment

Registered

2018-01-10

Start date

2018-03-22

Completion date

2025-12-11

Last updated

2026-02-23

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Immune Thrombocytopenia

Keywords

ITP

Brief summary

This was a 2 part (Part A and B) adaptive, open-label, dose-finding study of PRN1008 in patients with ITP who are refractory or relapsed with no available and approved therapeutic options, with a platelet count \<30,000/μL on two counts no sooner than 7 days apart in the 15 days before treatment begins. The dose-finding portion of the study was completed. Part B treatment dose was 400 mg twice daily.

Detailed description

This was a 2 part (Part A and B) adaptive, open-label, dose-finding study of PRN1008 in approximately 60 patients in Part A and approximately 25 patients in Part B. Part A enrolled patients with ITP who were refractory or relapsed with no available and approved therapeutic options. Eligible patients had a platelet count \<30,000/μL on two counts no sooner than 7 days apart in the 15 days before treatment begins. The active treatment period was 24 weeks and the post-treatment follow-up period is 4 weeks. In the dose-finding part of the study, each patient enrolled in the study was allowed to up-titrate their dose after 28 days of PRN1008 therapy, if they did not experience a platelet response or a dose-limiting toxicity (DLT) at the last dose level. Patients who responded to PRN1008 per protocol may enter a long term-extension. Part B of the study included approximately 25 patients with ITP who had relapsed or had an insufficient response to prior therapies. Eligible patients had a platelet count \<30,000/µL on two occasions no less than 7 days apart, within 15 days before treatment began and a platelet count of ≤35,000/µL on Study Day 1 (SD1). The study consisted of a 28-day screening period, 24-week active treatment period, and a long-term extension. After the last dose of PRN1008 there was a 4-week safety follow-up period.

Interventions

DRUGRilzabrutinib

BTK inhibitor

Study design

Allocation

Intervention model

SEQUENTIAL

Primary purpose

TREATMENT

Masking

NONE

Eligibility

Sex/Gender

ALL

Age

18 Years to 80 Years

Healthy volunteers

Inclusion criteria

* Male or female patients, aged 18 to 80 years old * Immune-related ITP (both primary and secondary)

Exclusion criteria

* Pregnant or lactating women * Current drug or alcohol abuse * History of solid organ transplant * Positive screening for HIV, hepatitis B, or hepatitis C

Design outcomes

Primary

Measure	Time frame	Description
Part B: Percentage of Participants Who Achieved Platelet Counts >=50,000/μL	Up to 24 Weeks	The percentage of participants who achieved platelet counts \>=50,000/μL on at least 8 out of the last 12 weeks of the 24-week treatment period without the use of rescue medication after 10 weeks of active treatment. 95% CI was based on the Clopper-Pearson exact method.
Part A: Number of Participants With Treatment-Emergent Adverse Events (TEAEs) and Treatment Related Treatment-Emergent Adverse Events	From first dose of rilzabrutinib (Day 1) up to last dose + 1 (up to 294 days)	Adverse event (AE): any untoward medical occurrence in participant or clinical study participant, temporally associated with the use of rilzabrutinib, whether or not considered related to rilzabrutinib. TEAEs: AEs that developed or worsened or became serious on or after the first dose administration of rilzabrutinib (Day 1). Any TEAEs are considered treatment-related TEAEs as per Investigator's evaluation of participant's circumstances surrounding the event, and an evaluation of any potential alternative causes to determine whether an TEAE can be considered as related to the rilzabrutinib.
Part B: Number of Participants With Treatment-Emergent Adverse Events and Treatment Related Treatment-Emergent Adverse Events	From first dose of rilzabrutinib (Day 1) up to last dose + 1 (approximately 170 days)	AE any untoward medical occurrence in participant or clinical study participant, temporally associated with the use of rilzabrutinib, whether or not considered related to rilzabrutinib. TEAEs: AEs that developed or worsened or became serious during the treatment-emergent period, defined as any time after the first dose administration of rilzabrutinib (Day 1). Any TEAEs are considered treatment-related TEAEs as per Investigator's evaluation of participant's circumstances surrounding the event, and an evaluation of any potential alternative causes to determine whether an TEAE can be considered as related to rilzabrutinib.
Part A: Percentage of Participants Who Achieved 2 or More Consecutive Platelet Counts by Starting Dose Level and Overall	Up to 24 Weeks	The percentage of participants who achieved 2 or more consecutive platelet counts, separated by at least 5 days, of \>=50,000/ microliter (μL) and an increase of platelet count of \>=20,000/μL from baseline, by starting dose level and overall, without use of rescue medication in the 4 weeks prior to the latest elevated platelet count. 95% confidence interval (CI) was based on the Clopper-Pearson method. The average of the 2 screening results and the Cycle 1 Day 1 result were used as the baseline value.

Secondary

Measure	Time frame	Description
Part A: Number of Weeks With Platelet Counts >=30,000/μL by Starting Dose Level and Overall	Up to 24 Weeks	The number of weeks in which participant achieved platelet counts \>=30,000/μL in the treatment period are summarized here. The number of weeks is based on the number of scheduled weekly assessments, by study day.
Part A: Time to First Platelet Count >=50,000/μL Across All Dose Levels	Up to 24 Weeks	Time to first platelet count \>=50,000/μL during the treatment period in days was calculated as: (date of first occurrence of platelet count \>=50,000/μL - date of first rilzabrutinib dosing) +1.
Part B: Number of Weeks With Platelet Counts >= 50,000/μL or >= 30,000/μL and Doubling the Baseline	Up to 24 Weeks	The number of weeks in which participant achieved platelet counts with thresholds as: \>=50,000/μL or \>=30,000/μL and doubling the baseline in the absence of rescue therapy (platelet counts will be censored for 4 weeks after the use of rescue medication, if given) are summarized here. Baseline is defined as the average of 3 platelet counts: 2 qualified screening platelet counts collected in electronic case report form (eCRF) and Week 1 (study day 1) platelet count.
Part B: Percentage of Participants Who Achieved 2 or More Consecutive Platelet Counts	Up to 24 Weeks	Percentage of participants who achieved 2 or more consecutive platelet counts, separated by at least 5 days, of \>=50,000/μL and an increase of platelet count of \>=20,000/μL from baseline without use of rescue medication in the 4 weeks prior to the latest elevated platelet count are summarized here. Baseline is defined as the average of 3 platelet counts: 2 qualified screening platelet counts collected in eCRF and Week 1 (study day 1) platelet count. 95% CI was based on the Clopper-Pearson exact method.
Part B: Number of Weeks With Platelet Counts >=30,000/μL and Doubling the Baseline	Up to 24 Weeks	The number of weeks in which participant achieved platelet counts \>=30,000/μL and doubling the baseline in the absence of rescue therapy (platelet counts will be censored for 4 weeks after the use of rescue medication, if given) are summarized here. Baseline is defined as the average of 3 platelet counts: 2 qualified screening platelet counts collected in eCRF and Week 1 (study day 1) platelet count.
Part B: Percentage of Participants Who Received Rescue Medication	Up to 24 Weeks	Rescue medication is defined as any therapy used to rescue a participant (1 of intravenous immunoglobulin \[IVIG\], high-dose steroids, platelet infusion or anti-D immunoglobulin infusion). Percentage of participants who received rescue medication are summarized here. 95% CI was based on the Clopper-Pearson exact method.
Part B: Change From Baseline in Idiopathic Thrombocytopenic Purpura Bleeding Scale (IBLS)	Baseline and up to 24 weeks	The IBLS is a bleeding assessment score. IBLS comprises of 11 sites for female and 10 sites for male, and each site is scored from 0 (none) to 2 (marked bleeding). The total overall score ranges from 0-22, with higher scores indicating higher presence of marked bleeding. For each participant, an IBLS score at each visit was calculated by taking the average across 11 items (10 for male and postmenopausal women) at 9 anatomical sites (8 for male and postmenopausal women). For each participant, a mean IBLS score was also calculated by taking the average across all post-baseline visits during the 24-week treatment period. IBLS average value ranges from 0 to 2. The smaller the IBLS average value is, the healthier the participants are. For change from baseline, negative value indicates an improvement. The baseline value is defined as the last available value before the first dose rilzabrutinib.
Part A: Percentage of Participants Who Received Rescue Medication by Dose Levels and Overall	Up to 24 Weeks	Rescue medication is defined as any therapy used to rescue a participant (1 of IVIG, high-dose steroids, platelet infusion or anti-D immunoglobulin infusion). The percentage of participants who received rescue medication for each dose level and overall are summarized here. 95% CI was based on the Clopper-Pearson method.
Part A: Percentage of Participants With Grade 2 or Higher Bleeding Event by Dose Level and Overall	Up to 24 Weeks	The percentage of participants with intensity grade 2 or higher bleeding event are summarized for each dose level and overall. The TEAEs with standardized medical dictionary for regulatory activities (MedDRA) query (SMQ) hemorrhages were medically determined for analysis of bleeding events. 95% CI was based on the Clopper-Pearson method.
Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Up to 24 Weeks	The ITP-BAT scale comprises of 11 grades from 0 (none) to 2 (marked bleeding), with higher scores indicating higher presence of marked bleeding, assessed at 9 anatomical sites (skin, oral, epistaxis, gastrointestinal \[GI\], urinary, gynecological \[GYN\], pulmonary, intracranial hemorrhage \[HEM\], subconjunctival HEM) by history over the previous week (Hx). In addition, 2 sites (skin and oral), were also assessed by physical examination (PE). The 'worst ever' bleeding experienced at each site was graded using the same system. Here, 0 indicates none; 1 indicates 1-5 bruises and/or scattered petechiae and 2 indicates \>5 bruises with size \>2 centimeter (cm) and/or diffuse petechiae. Each participant summed up the transformed scores across all 11 sites per visit assessment. The total overall score ranges from 0-22 with the higher score indicating worst outcome.
Part A: Maximum Observed Plasma Concentration (Cmax) of Rilzabrutinib	Day 1 of Cycles 1, 2, 3, and 5 (each cycle 28 days)	Plasma samples were collected at specified timepoints to determine Cmax of rilzabrutinib.
Part A: Time of Observed Maximum Plasma Concentration (Tmax) of Rilzabrutinib	Day 1 of Cycles 1, 2, 3, and 5 (each cycle 28 days)	Plasma samples were collected at specified timepoints to determine tmax of rilzabrutinib.
Part A: Area Under the Plasma Concentration-Time Curve From Time Zero to Last Quantifiable Concentration (AUClast) of Rilzabrutinib	Day 1 of Cycles 1, 2, 3, and 5 (each cycle 28 days)	Plasma samples were collected at specified timepoints to determine AUClast of rilzabrutinib.
Part A: Area Under the Plasma Concentration-Time Curve From Time Zero to Infinity (AUCinf) of Rilzabrutinib	Day 1 of Cycles 1, 2, and 3 (each cycle 28 days)	Plasma samples were collected at specified timepoints to determine AUCinf of rilzabrutinib.
Part A: Elimination Half-Life (t1/2) of Rilzabrutinib	Day 1 of Cycles 1, 2, and 3 (each cycle 28 days)	Plasma samples were collected at specified timepoints to determine t1/2 of rilzabrutinib.
Part A: Apparent Volume of Distribution of the Drug After Oral Administration (Vz/F) of Rilzabrutinib	Day 1 of Cycles 1, 2, and 3 (each cycle 28 days)	Plasma samples were collected at specified timepoints to determine Vz/F of rilzabrutinib.
Part A: Apparent Total Clearance of the Drug From Plasma After Oral Administration (CL/F) of Rilzabrutinib	Day 1 of Cycles 1, 2, and 3 (each cycle 28 days)	Plasma samples were collected at specified timepoints to determine CL/F of rilzabrutinib.
Part A: Percentage of Weeks With Platelet Counts >=50,000/μL by Starting Dose Level and Overall	Up to 24 Weeks	The percentage of weeks in which participants achieved platelet counts \>=50,000/μL in the treatment period are summarized here.
Part B: Plasma Concentration of Rilzabrutinib	Pre-dose and 2 hours post-dose on Days 1, 29, and 57	Plasma samples were collected at specified timepoints for evaluation of rilzabrutinib pharmacokinetic (PK) concentrations.
Part A: Percentage of Participants With 4 Out of the Final 8 Platelet Counts >=50,000/μL by Starting Dose Level and Overall	Up to 24 Weeks	The percentage of participants who had at least 4 out of the final 8 platelet counts \>=50,000/μL are summarized here. The final 8 scheduled platelet counts are the measurements performed in the last 8 weeks of rilzabrutinib (depending on treatment duration, not necessarily from Week 19 to Week 24) in the treatment period. 95% CI was based on the Clopper-Pearson method.
Part A: Change From Baseline to the Average of Post Day 1 Platelet Counts by Dose Level and Overall	Baseline and up to 24 Weeks	Average of post Day 1 platelet count is equivalent to average of (average of each participant's post-Day 1 platelet counts), included platelet counts up to 1 day after the date of last dose of rilzabrutinib and excluded platelet counts on or after date of rescue, if applicable. The average of the 2 screening results and the Cycle 1 Day 1 result measured on different date were used as the baseline value.
Part A: Number of Weeks With Platelet Counts >=50,000/μL by Starting Dose Level and Overall	Up to 24 Weeks	The number of weeks in which participant achieved platelet counts \>=50,000/μL in the treatment period are summarized here. The number of weeks is based on the number of scheduled weekly assessments, by study day.

Countries

Australia, Bulgaria, Canada, Czechia, Netherlands, Norway, United Kingdom, United States

Contacts

STUDY_DIRECTOROlga Bandman, MD

Principia Biopharma

Participant flow

Recruitment details

The study was conducted at 31 active centers in 8 countries. As prespecified in statistical analysis plan (SAP), Part A results were presented by either of the of the treatment group labels: Starting dose level (each participant was assigned to only one of the groups), dose level (dose received during the defined period. As most patients received more than one dose, a given patient could be assigned to multiple dose levels) and overall.

Pre-assignment details

A total of 60 participants in Part A and 26 participants in Part B were enrolled in the study. The results are presented up to primary completion date 31 January 2023.

Participants by arm

Arm	Count
Part A: Starting Dose 200 mg QD Participants received rilzabrutinib 200 mg orally QD as starting dose from Day 1 to 4 weeks. Participants were allowed to up-titrate the dose levels unless withdrawn, had a platelet response to current dose level, or the next dose level had been determined to be ineligible for further enrollment every 4 weeks up to the maximum allowed 400 mg BID (800 mg/day) over 24 weeks of treatment period.	9
Part A: Starting Dose 400 mg QD Participants received rilzabrutinib 400 mg orally QD as starting dose from Day 1 to 4 weeks. Participants were allowed to up-titrate the dose levels unless withdrawn, had a platelet response to current dose level, or the next dose level had been determined to be ineligible for further enrollment every 4 weeks up to the maximum allowed 400 mg BID (800 mg/day) over 24 weeks of treatment period.	1
Part A: Starting Dose 300 mg BID Participants received rilzabrutinib 300 mg orally BID as starting dose from Day 1 to 4 weeks. Participants were allowed to up-titrate the dose levels unless withdrawn, had a platelet response to current dose level, or the next dose level had been determined to be ineligible for further enrollment every 4 weeks up to the maximum allowed 400 mg BID (800 mg/day) over 24 weeks of treatment period.	5
Part A: Starting Dose 400 mg BID Participants received rilzabrutinib 400 mg orally BID as starting dose from Day 1 to 24 weeks, unless withdrawn or had a platelet response to current dose level.	45
Part B: Rilzabrutinib 400 mg BID Participants received rilzabrutinib 400 mg orally BID from Day 1 up to 24 weeks of treatment period.	26
Total	86

Baseline characteristics

Characteristic	Part A: Starting Dose 300 mg BID	Part A: Starting Dose 400 mg BID	Part B: Rilzabrutinib 400 mg BID	Total	Part A: Starting Dose 200 mg QD	Part A: Starting Dose 400 mg QD
Age, Customized <65 years	5 Participants	38 Participants	19 Participants	71 Participants	8 Participants	1 Participants
Age, Customized >= 65 years	0 Participants	7 Participants	7 Participants	15 Participants	1 Participants	0 Participants
Race/Ethnicity, Customized American Indian or Alaska Native	0 Participants	0 Participants	0 Participants	0 Participants	0 Participants	0 Participants
Race/Ethnicity, Customized Asian	0 Participants	2 Participants	4 Participants	6 Participants	0 Participants	0 Participants
Race/Ethnicity, Customized Black or African American	0 Participants	0 Participants	0 Participants	0 Participants	0 Participants	0 Participants
Race/Ethnicity, Customized Native Hawaiian or Other Pacific Islander	0 Participants	1 Participants	0 Participants	1 Participants	0 Participants	0 Participants
Race/Ethnicity, Customized Other	0 Participants	3 Participants	1 Participants	4 Participants	0 Participants	0 Participants
Race/Ethnicity, Customized White	5 Participants	39 Participants	21 Participants	75 Participants	9 Participants	1 Participants
Sex: Female, Male Female	3 Participants	27 Participants	16 Participants	50 Participants	4 Participants	0 Participants
Sex: Female, Male Male	2 Participants	18 Participants	10 Participants	36 Participants	5 Participants	1 Participants

Adverse events

Event type	EG000 affected / at risk	EG001 affected / at risk	EG002 affected / at risk	EG003 affected / at risk	EG004 affected / at risk	EG005 affected / at risk
deaths Total, all-cause mortality	0 / 9	0 / 8	0 / 12	1 / 52	1 / 60	0 / 26
other Total, other adverse events	5 / 9	6 / 8	9 / 12	43 / 52	48 / 60	21 / 26
serious Total, serious adverse events	1 / 9	2 / 8	3 / 12	9 / 52	11 / 60	3 / 26

Outcome results

Primary

Part A: Number of Participants With Treatment-Emergent Adverse Events (TEAEs) and Treatment Related Treatment-Emergent Adverse Events

Adverse event (AE): any untoward medical occurrence in participant or clinical study participant, temporally associated with the use of rilzabrutinib, whether or not considered related to rilzabrutinib. TEAEs: AEs that developed or worsened or became serious on or after the first dose administration of rilzabrutinib (Day 1). Any TEAEs are considered treatment-related TEAEs as per Investigator's evaluation of participant's circumstances surrounding the event, and an evaluation of any potential alternative causes to determine whether an TEAE can be considered as related to the rilzabrutinib.

Time frame: From first dose of rilzabrutinib (Day 1) up to last dose + 1 (up to 294 days)

Population: Safety population consisted of all participants who received at least 1 dose of rilzabrutinib. It was prespecified (SAP), data was analyzed by overall and dose level and participants could be classified into multiple dose levels.

Arm	Measure	Group	Value (COUNT_OF_PARTICIPANTS)
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Treatment-Emergent Adverse Events (TEAEs) and Treatment Related Treatment-Emergent Adverse Events	TEAEs	3 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Treatment-Emergent Adverse Events (TEAEs) and Treatment Related Treatment-Emergent Adverse Events	Treatment related TEAEs	2 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Treatment-Emergent Adverse Events (TEAEs) and Treatment Related Treatment-Emergent Adverse Events	TEAEs	3 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Treatment-Emergent Adverse Events (TEAEs) and Treatment Related Treatment-Emergent Adverse Events	Treatment related TEAEs	2 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Treatment-Emergent Adverse Events (TEAEs) and Treatment Related Treatment-Emergent Adverse Events	TEAEs	5 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Treatment-Emergent Adverse Events (TEAEs) and Treatment Related Treatment-Emergent Adverse Events	Treatment related TEAEs	2 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Treatment-Emergent Adverse Events (TEAEs) and Treatment Related Treatment-Emergent Adverse Events	Treatment related TEAEs	29 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Treatment-Emergent Adverse Events (TEAEs) and Treatment Related Treatment-Emergent Adverse Events	TEAEs	44 Participants
Part A: Overall	Part A: Number of Participants With Treatment-Emergent Adverse Events (TEAEs) and Treatment Related Treatment-Emergent Adverse Events	TEAEs	48 Participants
Part A: Overall	Part A: Number of Participants With Treatment-Emergent Adverse Events (TEAEs) and Treatment Related Treatment-Emergent Adverse Events	Treatment related TEAEs	31 Participants

Primary

Part A: Percentage of Participants Who Achieved 2 or More Consecutive Platelet Counts by Starting Dose Level and Overall

The percentage of participants who achieved 2 or more consecutive platelet counts, separated by at least 5 days, of \>=50,000/ microliter (μL) and an increase of platelet count of \>=20,000/μL from baseline, by starting dose level and overall, without use of rescue medication in the 4 weeks prior to the latest elevated platelet count. 95% confidence interval (CI) was based on the Clopper-Pearson method. The average of the 2 screening results and the Cycle 1 Day 1 result were used as the baseline value.

Time frame: Up to 24 Weeks

Population: ITT population consisted of all participants who had enrolled into the study. It was prespecified (SAP), data was analyzed by overall and starting dose level.

Arm	Measure	Value (NUMBER)
Part A: Starting Dose 200 mg QD	Part A: Percentage of Participants Who Achieved 2 or More Consecutive Platelet Counts by Starting Dose Level and Overall	44.4 percentage of participants
Part A: Starting Dose 400 mg QD	Part A: Percentage of Participants Who Achieved 2 or More Consecutive Platelet Counts by Starting Dose Level and Overall	0.0 percentage of participants
Part A: Starting Dose 300 mg BID	Part A: Percentage of Participants Who Achieved 2 or More Consecutive Platelet Counts by Starting Dose Level and Overall	40.0 percentage of participants
Part A: Starting Dose 400 mg BID	Part A: Percentage of Participants Who Achieved 2 or More Consecutive Platelet Counts by Starting Dose Level and Overall	40.0 percentage of participants
Part A: Overall	Part A: Percentage of Participants Who Achieved 2 or More Consecutive Platelet Counts by Starting Dose Level and Overall	40.0 percentage of participants

Primary

Part B: Number of Participants With Treatment-Emergent Adverse Events and Treatment Related Treatment-Emergent Adverse Events

AE any untoward medical occurrence in participant or clinical study participant, temporally associated with the use of rilzabrutinib, whether or not considered related to rilzabrutinib. TEAEs: AEs that developed or worsened or became serious during the treatment-emergent period, defined as any time after the first dose administration of rilzabrutinib (Day 1). Any TEAEs are considered treatment-related TEAEs as per Investigator's evaluation of participant's circumstances surrounding the event, and an evaluation of any potential alternative causes to determine whether an TEAE can be considered as related to rilzabrutinib.

Time frame: From first dose of rilzabrutinib (Day 1) up to last dose + 1 (approximately 170 days)

Population: Safety population consisted of all participants who had taken rilzabrutinib, regardless of the amount administered.

Arm	Measure	Group	Value (COUNT_OF_PARTICIPANTS)
Part A: Starting Dose 200 mg QD	Part B: Number of Participants With Treatment-Emergent Adverse Events and Treatment Related Treatment-Emergent Adverse Events	TEAEs	22 Participants
Part A: Starting Dose 200 mg QD	Part B: Number of Participants With Treatment-Emergent Adverse Events and Treatment Related Treatment-Emergent Adverse Events	Treatment related TEAEs	16 Participants

Primary

Part B: Percentage of Participants Who Achieved Platelet Counts >=50,000/μL

The percentage of participants who achieved platelet counts \>=50,000/μL on at least 8 out of the last 12 weeks of the 24-week treatment period without the use of rescue medication after 10 weeks of active treatment. 95% CI was based on the Clopper-Pearson exact method.

Time frame: Up to 24 Weeks

Population: ITT population consisted of all enrolled participants.

Arm	Measure	Value (NUMBER)
Part A: Starting Dose 200 mg QD	Part B: Percentage of Participants Who Achieved Platelet Counts >=50,000/μL	34.6 percentage of participants

Secondary

Part A: Apparent Total Clearance of the Drug From Plasma After Oral Administration (CL/F) of Rilzabrutinib

Plasma samples were collected at specified timepoints to determine CL/F of rilzabrutinib.

Time frame: Day 1 of Cycles 1, 2, and 3 (each cycle 28 days)

Population: ITT population consisted of all participants who had enrolled into the study. It was prespecified (SAP), data was analyzed based on frequent sampling on Day 1 of a new, higher dosing level and reported by dose. Only participants who received rilzabrutinib with data collected at specified timepoints are reported.

Arm	Measure	Group	Value (MEAN)	Dispersion
Part A: Starting Dose 200 mg QD	Part A: Apparent Total Clearance of the Drug From Plasma After Oral Administration (CL/F) of Rilzabrutinib	Cycle 1 Day 1	911 liters/hour	Standard Deviation 569
Part A: Starting Dose 400 mg QD	Part A: Apparent Total Clearance of the Drug From Plasma After Oral Administration (CL/F) of Rilzabrutinib	Cycle 2 Day 1	743 liters/hour	Standard Deviation 593
Part A: Starting Dose 300 mg BID	Part A: Apparent Total Clearance of the Drug From Plasma After Oral Administration (CL/F) of Rilzabrutinib	Cycle 1 Day 1	592 liters/hour	Standard Deviation 320
Part A: Starting Dose 300 mg BID	Part A: Apparent Total Clearance of the Drug From Plasma After Oral Administration (CL/F) of Rilzabrutinib	Cycle 3 Day 1	713 liters/hour	Standard Deviation 621
Part A: Starting Dose 400 mg BID	Part A: Apparent Total Clearance of the Drug From Plasma After Oral Administration (CL/F) of Rilzabrutinib	Cycle 1 Day 1	854 liters/hour	Standard Deviation 551
Part A: Starting Dose 400 mg BID	Part A: Apparent Total Clearance of the Drug From Plasma After Oral Administration (CL/F) of Rilzabrutinib	Cycle 2 Day 1	484 liters/hour	—

Secondary

Part A: Apparent Volume of Distribution of the Drug After Oral Administration (Vz/F) of Rilzabrutinib

Plasma samples were collected at specified timepoints to determine Vz/F of rilzabrutinib.

Time frame: Day 1 of Cycles 1, 2, and 3 (each cycle 28 days)

Arm	Measure	Group	Value (MEAN)	Dispersion
Part A: Starting Dose 200 mg QD	Part A: Apparent Volume of Distribution of the Drug After Oral Administration (Vz/F) of Rilzabrutinib	Cycle 1 Day 1	1780 Liters	Standard Deviation 1180
Part A: Starting Dose 400 mg QD	Part A: Apparent Volume of Distribution of the Drug After Oral Administration (Vz/F) of Rilzabrutinib	Cycle 2 Day 1	2090 Liters	Standard Deviation 2640
Part A: Starting Dose 300 mg BID	Part A: Apparent Volume of Distribution of the Drug After Oral Administration (Vz/F) of Rilzabrutinib	Cycle 1 Day 1	1180 Liters	Standard Deviation 611
Part A: Starting Dose 300 mg BID	Part A: Apparent Volume of Distribution of the Drug After Oral Administration (Vz/F) of Rilzabrutinib	Cycle 3 Day 1	1650 Liters	Standard Deviation 1510
Part A: Starting Dose 400 mg BID	Part A: Apparent Volume of Distribution of the Drug After Oral Administration (Vz/F) of Rilzabrutinib	Cycle 1 Day 1	1720 Liters	Standard Deviation 1460
Part A: Starting Dose 400 mg BID	Part A: Apparent Volume of Distribution of the Drug After Oral Administration (Vz/F) of Rilzabrutinib	Cycle 2 Day 1	934 Liters	—

Secondary

Part A: Area Under the Plasma Concentration-Time Curve From Time Zero to Infinity (AUCinf) of Rilzabrutinib

Plasma samples were collected at specified timepoints to determine AUCinf of rilzabrutinib.

Time frame: Day 1 of Cycles 1, 2, and 3 (each cycle 28 days)

Arm	Measure	Group	Value (MEAN)	Dispersion
Part A: Starting Dose 200 mg QD	Part A: Area Under the Plasma Concentration-Time Curve From Time Zero to Infinity (AUCinf) of Rilzabrutinib	Cycle 1 Day 1	331 h*ng/mL	Standard Deviation 224
Part A: Starting Dose 400 mg QD	Part A: Area Under the Plasma Concentration-Time Curve From Time Zero to Infinity (AUCinf) of Rilzabrutinib	Cycle 2 Day 1	787 h*ng/mL	Standard Deviation 446
Part A: Starting Dose 300 mg BID	Part A: Area Under the Plasma Concentration-Time Curve From Time Zero to Infinity (AUCinf) of Rilzabrutinib	Cycle 1 Day 1	653 h*ng/mL	Standard Deviation 351
Part A: Starting Dose 300 mg BID	Part A: Area Under the Plasma Concentration-Time Curve From Time Zero to Infinity (AUCinf) of Rilzabrutinib	Cycle 3 Day 1	818 h*ng/mL	Standard Deviation 671
Part A: Starting Dose 400 mg BID	Part A: Area Under the Plasma Concentration-Time Curve From Time Zero to Infinity (AUCinf) of Rilzabrutinib	Cycle 1 Day 1	703 h*ng/mL	Standard Deviation 455
Part A: Starting Dose 400 mg BID	Part A: Area Under the Plasma Concentration-Time Curve From Time Zero to Infinity (AUCinf) of Rilzabrutinib	Cycle 2 Day 1	827 h*ng/mL	—

Secondary

Part A: Area Under the Plasma Concentration-Time Curve From Time Zero to Last Quantifiable Concentration (AUClast) of Rilzabrutinib

Plasma samples were collected at specified timepoints to determine AUClast of rilzabrutinib.

Time frame: Day 1 of Cycles 1, 2, 3, and 5 (each cycle 28 days)

Arm	Measure	Group	Value (MEAN)	Dispersion
Part A: Starting Dose 200 mg QD	Part A: Area Under the Plasma Concentration-Time Curve From Time Zero to Last Quantifiable Concentration (AUClast) of Rilzabrutinib	Cycle 1 Day 1	320 h*ng/mL	Standard Deviation 217
Part A: Starting Dose 400 mg QD	Part A: Area Under the Plasma Concentration-Time Curve From Time Zero to Last Quantifiable Concentration (AUClast) of Rilzabrutinib	Cycle 2 Day 1	986 h*ng/mL	Standard Deviation 646
Part A: Starting Dose 300 mg BID	Part A: Area Under the Plasma Concentration-Time Curve From Time Zero to Last Quantifiable Concentration (AUClast) of Rilzabrutinib	Cycle 1 Day 1	616 h*ng/mL	Standard Deviation 334
Part A: Starting Dose 300 mg BID	Part A: Area Under the Plasma Concentration-Time Curve From Time Zero to Last Quantifiable Concentration (AUClast) of Rilzabrutinib	Cycle 3 Day 1	788 h*ng/mL	Standard Deviation 610
Part A: Starting Dose 400 mg BID	Part A: Area Under the Plasma Concentration-Time Curve From Time Zero to Last Quantifiable Concentration (AUClast) of Rilzabrutinib	Cycle 1 Day 1	642 h*ng/mL	Standard Deviation 435
Part A: Starting Dose 400 mg BID	Part A: Area Under the Plasma Concentration-Time Curve From Time Zero to Last Quantifiable Concentration (AUClast) of Rilzabrutinib	Cycle 2 Day 1	1150 h*ng/mL	Standard Deviation 1030
Part A: Starting Dose 400 mg BID	Part A: Area Under the Plasma Concentration-Time Curve From Time Zero to Last Quantifiable Concentration (AUClast) of Rilzabrutinib	Cycle 5 Day 1	872 h*ng/mL	Standard Deviation 412

Secondary

Part A: Change From Baseline to the Average of Post Day 1 Platelet Counts by Dose Level and Overall

Average of post Day 1 platelet count is equivalent to average of (average of each participant's post-Day 1 platelet counts), included platelet counts up to 1 day after the date of last dose of rilzabrutinib and excluded platelet counts on or after date of rescue, if applicable. The average of the 2 screening results and the Cycle 1 Day 1 result measured on different date were used as the baseline value.

Time frame: Baseline and up to 24 Weeks

Population: ITT population consisted of all participants who had enrolled into the study. It was prespecified (SAP), data was analyzed by overall and dose level and participants can be classified into multiple dose levels. Only participants with data who had more than 4 weeks of rilzabrutinib within a dose level are reported in each dose level. Participants with more than 4 weeks of study drug across all dose levels are included in overall.

Arm	Measure	Value (MEAN)	Dispersion
Part A: Starting Dose 200 mg QD	Part A: Change From Baseline to the Average of Post Day 1 Platelet Counts by Dose Level and Overall	6.92 platelets x10^9/Liter (L)	Standard Deviation 22.52
Part A: Starting Dose 400 mg QD	Part A: Change From Baseline to the Average of Post Day 1 Platelet Counts by Dose Level and Overall	68.10 platelets x10^9/Liter (L)	—
Part A: Starting Dose 300 mg BID	Part A: Change From Baseline to the Average of Post Day 1 Platelet Counts by Dose Level and Overall	37.05 platelets x10^9/Liter (L)	Standard Deviation 29.1
Part A: Starting Dose 400 mg BID	Part A: Change From Baseline to the Average of Post Day 1 Platelet Counts by Dose Level and Overall	29.92 platelets x10^9/Liter (L)	Standard Deviation 41.7
Part A: Overall	Part A: Change From Baseline to the Average of Post Day 1 Platelet Counts by Dose Level and Overall	28.61 platelets x10^9/Liter (L)	Standard Deviation 39.57

Secondary

Part A: Elimination Half-Life (t1/2) of Rilzabrutinib

Plasma samples were collected at specified timepoints to determine t1/2 of rilzabrutinib.

Time frame: Day 1 of Cycles 1, 2, and 3 (each cycle 28 days)

Arm	Measure	Group	Value (MEDIAN)
Part A: Starting Dose 200 mg QD	Part A: Elimination Half-Life (t1/2) of Rilzabrutinib	Cycle 1 Day 1	1.36 hours
Part A: Starting Dose 400 mg QD	Part A: Elimination Half-Life (t1/2) of Rilzabrutinib	Cycle 2 Day 1	1.52 hours
Part A: Starting Dose 300 mg BID	Part A: Elimination Half-Life (t1/2) of Rilzabrutinib	Cycle 1 Day 1	1.30 hours
Part A: Starting Dose 300 mg BID	Part A: Elimination Half-Life (t1/2) of Rilzabrutinib	Cycle 3 Day 1	1.60 hours
Part A: Starting Dose 400 mg BID	Part A: Elimination Half-Life (t1/2) of Rilzabrutinib	Cycle 1 Day 1	1.32 hours
Part A: Starting Dose 400 mg BID	Part A: Elimination Half-Life (t1/2) of Rilzabrutinib	Cycle 2 Day 1	1.34 hours

Secondary

Part A: Maximum Observed Plasma Concentration (Cmax) of Rilzabrutinib

Plasma samples were collected at specified timepoints to determine Cmax of rilzabrutinib.

Time frame: Day 1 of Cycles 1, 2, 3, and 5 (each cycle 28 days)

Arm	Measure	Group	Value (MEAN)	Dispersion
Part A: Starting Dose 200 mg QD	Part A: Maximum Observed Plasma Concentration (Cmax) of Rilzabrutinib	Cycle 1 Day 1	154 nanogram per milliliter (ng/mL)	Standard Deviation 117
Part A: Starting Dose 400 mg QD	Part A: Maximum Observed Plasma Concentration (Cmax) of Rilzabrutinib	Cycle 2 Day 1	451 nanogram per milliliter (ng/mL)	Standard Deviation 408
Part A: Starting Dose 300 mg BID	Part A: Maximum Observed Plasma Concentration (Cmax) of Rilzabrutinib	Cycle 1 Day 1	287 nanogram per milliliter (ng/mL)	Standard Deviation 149
Part A: Starting Dose 300 mg BID	Part A: Maximum Observed Plasma Concentration (Cmax) of Rilzabrutinib	Cycle 3 Day 1	319 nanogram per milliliter (ng/mL)	Standard Deviation 266
Part A: Starting Dose 400 mg BID	Part A: Maximum Observed Plasma Concentration (Cmax) of Rilzabrutinib	Cycle 1 Day 1	273 nanogram per milliliter (ng/mL)	Standard Deviation 203
Part A: Starting Dose 400 mg BID	Part A: Maximum Observed Plasma Concentration (Cmax) of Rilzabrutinib	Cycle 2 Day 1	396 nanogram per milliliter (ng/mL)	Standard Deviation 257
Part A: Starting Dose 400 mg BID	Part A: Maximum Observed Plasma Concentration (Cmax) of Rilzabrutinib	Cycle 5 Day 1	447 nanogram per milliliter (ng/mL)	Standard Deviation 67.2

Secondary

Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level

The ITP-BAT scale comprises of 11 grades from 0 (none) to 2 (marked bleeding), with higher scores indicating higher presence of marked bleeding, assessed at 9 anatomical sites (skin, oral, epistaxis, gastrointestinal \[GI\], urinary, gynecological \[GYN\], pulmonary, intracranial hemorrhage \[HEM\], subconjunctival HEM) by history over the previous week (Hx). In addition, 2 sites (skin and oral), were also assessed by physical examination (PE). The 'worst ever' bleeding experienced at each site was graded using the same system. Here, 0 indicates none; 1 indicates 1-5 bruises and/or scattered petechiae and 2 indicates \>5 bruises with size \>2 centimeter (cm) and/or diffuse petechiae. Each participant summed up the transformed scores across all 11 sites per visit assessment. The total overall score ranges from 0-22 with the higher score indicating worst outcome.

Time frame: Up to 24 Weeks

Population: Safety population consisted of all participants who received at least 1 dose of rilzabrutinib. It was prespecified (SAP), data was analyzed by dose level and participants can be classified into multiple dose levels.

Arm	Measure	Group	Value (COUNT_OF_PARTICIPANTS)
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GI: Score 2	0 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Epistaxis: Scoring not done/missing	2 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (Hx): Score 1	0 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Urinary: Scoring not done/missing	2 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (Hx): Score 2	0 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Epistaxis: Score 2	0 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (Hx): Scoring not done/missing	2 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (Hx): Score 0	7 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Pulmonary: Scoring not done/missing	3 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Epistaxis: Score 1	0 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (Hx): Score 1	0 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GYN: Score 0	1 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (Hx): Score 2	0 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Epistaxis: Score 0	7 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (Hx): Scoring not done/missing	2 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GYN: Score 1	0 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Intracranial HEM: Scoring not done/missing	2 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Intracranial HEM: Score 0	7 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GYN: Score 2	0 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Subconjunctival HEM: Score 2	0 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GYN: Scoring not done/missing	8 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Urinary: Score 1	0 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Pulmonary: Score 0	6 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Subconjunctival HEM: Score 0	7 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Pulmonary: Score 1	0 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Intracranial HEM: Score 2	0 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Urinary: Score 0	7 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Pulmonary: Score 2	0 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (PE): Score 0	7 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Subconjunctival HEM: Scoring not done/missing	2 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GI: Scoring not done/missing	2 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (PE): Score 1	0 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (PE): Score 2	0 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (PE): Scoring not done/missing	2 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (PE): Score 0	7 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Intracranial HEM: Score 1	0 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GI: Score 1	0 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (PE): Score 1	0 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Urinary: Score 2	0 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (PE): Score 2	0 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GI: Score 0	7 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (PE): Scoring not done/missing	2 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Subconjunctival HEM: Score 1	0 Participants
Part A: Starting Dose 200 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (Hx): Score 0	7 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (PE): Scoring not done/missing	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Urinary: Score 0	8 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Intracranial HEM: Score 1	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (Hx): Score 1	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Pulmonary: Score 1	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Epistaxis: Score 2	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GI: Score 1	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (Hx): Score 2	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Urinary: Scoring not done/missing	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (PE): Scoring not done/missing	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (PE): Score 0	8 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (Hx): Scoring not done/missing	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Subconjunctival HEM: Score 1	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Epistaxis: Score 1	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Pulmonary: Score 2	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (Hx): Score 0	8 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GI: Scoring not done/missing	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Intracranial HEM: Score 2	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (PE): Score 2	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (Hx): Score 1	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (PE): Score 0	8 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Epistaxis: Score 0	8 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Urinary: Score 2	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (Hx): Score 2	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GYN: Score 0	1 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (Hx): Score 0	8 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (PE): Score 1	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (Hx): Scoring not done/missing	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Subconjunctival HEM: Score 0	8 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Intracranial HEM: Score 0	8 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (PE): Score 1	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GYN: Score 1	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Subconjunctival HEM: Scoring not done/missing	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GI: Score 2	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Epistaxis: Scoring not done/missing	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GYN: Score 2	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (PE): Score 2	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Urinary: Score 1	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Intracranial HEM: Scoring not done/missing	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GYN: Scoring not done/missing	7 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Subconjunctival HEM: Score 2	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Pulmonary: Scoring not done/missing	0 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GI: Score 0	8 Participants
Part A: Starting Dose 400 mg QD	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Pulmonary: Score 0	8 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Intracranial HEM: Scoring not done/missing	4 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Subconjunctival HEM: Score 0	8 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Subconjunctival HEM: Score 1	0 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Subconjunctival HEM: Score 2	0 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Subconjunctival HEM: Scoring not done/missing	4 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Urinary: Score 2	0 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Urinary: Scoring not done/missing	3 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GYN: Score 0	4 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GYN: Score 1	0 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GYN: Score 2	0 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GYN: Scoring not done/missing	8 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Pulmonary: Score 0	8 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Pulmonary: Score 1	0 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (PE): Score 0	6 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (PE): Score 1	3 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (PE): Score 2	0 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (PE): Scoring not done/missing	3 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (PE): Score 0	9 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (PE): Score 1	0 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (PE): Score 2	0 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (PE): Scoring not done/missing	3 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (Hx): Score 0	5 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (Hx): Score 1	4 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (Hx): Score 2	0 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (Hx): Scoring not done/missing	3 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (Hx): Score 0	9 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (Hx): Score 1	0 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (Hx): Score 2	0 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (Hx): Scoring not done/missing	3 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Epistaxis: Score 0	9 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Epistaxis: Score 1	0 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Epistaxis: Score 2	0 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Epistaxis: Scoring not done/missing	3 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GI: Score 0	10 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GI: Score 1	0 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GI: Score 2	0 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GI: Scoring not done/missing	2 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Urinary: Score 0	9 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Urinary: Score 1	0 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Pulmonary: Score 2	0 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Intracranial HEM: Score 0	8 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Pulmonary: Scoring not done/missing	4 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Intracranial HEM: Score 1	0 Participants
Part A: Starting Dose 300 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Intracranial HEM: Score 2	0 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Subconjunctival HEM: Score 1	0 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Epistaxis: Scoring not done/missing	2 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (PE): Score 2	4 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (PE): Score 1	4 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Intracranial HEM: Score 0	49 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GI: Score 0	49 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (PE): Score 0	42 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (PE): Scoring not done/missing	2 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Pulmonary: Scoring not done/missing	3 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GI: Score 1	1 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (PE): Score 2	6 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (PE): Score 1	12 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Subconjunctival HEM: Scoring not done/missing	2 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GI: Score 2	0 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (PE): Score 0	32 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Pulmonary: Score 2	0 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Subconjunctival HEM: Score 0	50 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GI: Scoring not done/missing	2 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Pulmonary: Score 1	0 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Pulmonary: Score 0	49 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Intracranial HEM: Score 1	0 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Urinary: Score 0	48 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GYN: Scoring not done/missing	28 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GYN: Score 2	1 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Subconjunctival HEM: Score 2	0 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Urinary: Score 1	2 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Intracranial HEM: Scoring not done/missing	3 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GYN: Score 1	1 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	GYN: Score 0	22 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (Hx): Scoring not done/missing	2 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (Hx): Score 2	5 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (Hx): Score 1	2 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Intracranial HEM: Score 2	0 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Epistaxis: Score 0	49 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (Hx): Score 0	43 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (Hx): Scoring not done/missing	2 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Urinary: Scoring not done/missing	2 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Epistaxis: Score 1	0 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (Hx): Score 2	5 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (Hx): Score 1	11 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Urinary: Score 2	0 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Epistaxis: Score 2	1 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Skin (Hx): Score 0	34 Participants
Part A: Starting Dose 400 mg BID	Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level	Oral (PE): Scoring not done/missing	2 Participants

Secondary

Part A: Number of Weeks With Platelet Counts >=30,000/μL by Starting Dose Level and Overall

The number of weeks in which participant achieved platelet counts \>=30,000/μL in the treatment period are summarized here. The number of weeks is based on the number of scheduled weekly assessments, by study day.

Time frame: Up to 24 Weeks

Population: ITT population consisted of all participants who had enrolled into the study. Only participants with data collected at specified timepoints are reported. It was prespecified (SAP), data was analyzed by overall and starting dose level.

Arm	Measure	Value (MEAN)	Dispersion
Part A: Starting Dose 200 mg QD	Part A: Number of Weeks With Platelet Counts >=30,000/μL by Starting Dose Level and Overall	8.4 weeks	Standard Deviation 11.2
Part A: Starting Dose 400 mg QD	Part A: Number of Weeks With Platelet Counts >=30,000/μL by Starting Dose Level and Overall	0.0 weeks	—
Part A: Starting Dose 300 mg BID	Part A: Number of Weeks With Platelet Counts >=30,000/μL by Starting Dose Level and Overall	14.0 weeks	Standard Deviation 14.1
Part A: Starting Dose 400 mg BID	Part A: Number of Weeks With Platelet Counts >=30,000/μL by Starting Dose Level and Overall	8.8 weeks	Standard Deviation 9.2
Part A: Overall	Part A: Number of Weeks With Platelet Counts >=30,000/μL by Starting Dose Level and Overall	9.0 weeks	Standard Deviation 9.8

Secondary

Part A: Number of Weeks With Platelet Counts >=50,000/μL by Starting Dose Level and Overall

The number of weeks in which participant achieved platelet counts \>=50,000/μL in the treatment period are summarized here. The number of weeks is based on the number of scheduled weekly assessments, by study day.

Time frame: Up to 24 Weeks

Arm	Measure	Value (MEAN)	Dispersion
Part A: Starting Dose 200 mg QD	Part A: Number of Weeks With Platelet Counts >=50,000/μL by Starting Dose Level and Overall	5.9 weeks	Standard Deviation 7.8
Part A: Starting Dose 400 mg QD	Part A: Number of Weeks With Platelet Counts >=50,000/μL by Starting Dose Level and Overall	0.0 weeks	—
Part A: Starting Dose 300 mg BID	Part A: Number of Weeks With Platelet Counts >=50,000/μL by Starting Dose Level and Overall	10.2 weeks	Standard Deviation 12
Part A: Starting Dose 400 mg BID	Part A: Number of Weeks With Platelet Counts >=50,000/μL by Starting Dose Level and Overall	5.7 weeks	Standard Deviation 8.1
Part A: Overall	Part A: Number of Weeks With Platelet Counts >=50,000/μL by Starting Dose Level and Overall	6.0 weeks	Standard Deviation 8.3

Secondary

Part A: Percentage of Participants Who Received Rescue Medication by Dose Levels and Overall

Rescue medication is defined as any therapy used to rescue a participant (1 of IVIG, high-dose steroids, platelet infusion or anti-D immunoglobulin infusion). The percentage of participants who received rescue medication for each dose level and overall are summarized here. 95% CI was based on the Clopper-Pearson method.

Time frame: Up to 24 Weeks

Population: Safety population consisted of all participants who received at least 1 dose of rilzabrutinib. Participants are classified into different dose levels according to the dose received at the start of rescue medication. A given participant can be classified into multiple dose levels. It was prespecified (SAP), data was analyzed by overall and dose level.

Arm	Measure	Value (NUMBER)
Part A: Starting Dose 200 mg QD	Part A: Percentage of Participants Who Received Rescue Medication by Dose Levels and Overall	11.1 percentage of participants
Part A: Starting Dose 400 mg QD	Part A: Percentage of Participants Who Received Rescue Medication by Dose Levels and Overall	0.0 percentage of participants
Part A: Starting Dose 300 mg BID	Part A: Percentage of Participants Who Received Rescue Medication by Dose Levels and Overall	8.3 percentage of participants
Part A: Starting Dose 400 mg BID	Part A: Percentage of Participants Who Received Rescue Medication by Dose Levels and Overall	9.6 percentage of participants
Part A: Overall	Part A: Percentage of Participants Who Received Rescue Medication by Dose Levels and Overall	11.7 percentage of participants

Secondary

Part A: Percentage of Participants With 4 Out of the Final 8 Platelet Counts >=50,000/μL by Starting Dose Level and Overall

The percentage of participants who had at least 4 out of the final 8 platelet counts \>=50,000/μL are summarized here. The final 8 scheduled platelet counts are the measurements performed in the last 8 weeks of rilzabrutinib (depending on treatment duration, not necessarily from Week 19 to Week 24) in the treatment period. 95% CI was based on the Clopper-Pearson method.

Time frame: Up to 24 Weeks

Population: ITT population consisted of all participants who had enrolled into the study. It was prespecified (SAP), data was analyzed by overall and starting dose level.

Arm	Measure	Value (NUMBER)
Part A: Starting Dose 200 mg QD	Part A: Percentage of Participants With 4 Out of the Final 8 Platelet Counts >=50,000/μL by Starting Dose Level and Overall	11.1 percentage of participants
Part A: Starting Dose 400 mg QD	Part A: Percentage of Participants With 4 Out of the Final 8 Platelet Counts >=50,000/μL by Starting Dose Level and Overall	0.0 percentage of participants
Part A: Starting Dose 300 mg BID	Part A: Percentage of Participants With 4 Out of the Final 8 Platelet Counts >=50,000/μL by Starting Dose Level and Overall	40.0 percentage of participants
Part A: Starting Dose 400 mg BID	Part A: Percentage of Participants With 4 Out of the Final 8 Platelet Counts >=50,000/μL by Starting Dose Level and Overall	31.1 percentage of participants
Part A: Overall	Part A: Percentage of Participants With 4 Out of the Final 8 Platelet Counts >=50,000/μL by Starting Dose Level and Overall	28.3 percentage of participants

Secondary

Part A: Percentage of Participants With Grade 2 or Higher Bleeding Event by Dose Level and Overall

The percentage of participants with intensity grade 2 or higher bleeding event are summarized for each dose level and overall. The TEAEs with standardized medical dictionary for regulatory activities (MedDRA) query (SMQ) hemorrhages were medically determined for analysis of bleeding events. 95% CI was based on the Clopper-Pearson method.

Time frame: Up to 24 Weeks

Population: Safety population consisted of all participants who received at least 1 dose of rilzabrutinib. Participants are classified into different dose levels according to the dose received at the start of the bleeding event. A given participant can be classified into multiple dose levels. It was prespecified (SAP), data was analyzed by overall and dose level.

Arm	Measure	Value (NUMBER)
Part A: Starting Dose 200 mg QD	Part A: Percentage of Participants With Grade 2 or Higher Bleeding Event by Dose Level and Overall	0.0 percentage of participants
Part A: Starting Dose 400 mg QD	Part A: Percentage of Participants With Grade 2 or Higher Bleeding Event by Dose Level and Overall	0.0 percentage of participants
Part A: Starting Dose 300 mg BID	Part A: Percentage of Participants With Grade 2 or Higher Bleeding Event by Dose Level and Overall	8.3 percentage of participants
Part A: Starting Dose 400 mg BID	Part A: Percentage of Participants With Grade 2 or Higher Bleeding Event by Dose Level and Overall	17.3 percentage of participants
Part A: Overall	Part A: Percentage of Participants With Grade 2 or Higher Bleeding Event by Dose Level and Overall	16.7 percentage of participants

Secondary

Part A: Percentage of Weeks With Platelet Counts >=50,000/μL by Starting Dose Level and Overall

The percentage of weeks in which participants achieved platelet counts \>=50,000/μL in the treatment period are summarized here.

Time frame: Up to 24 Weeks

Arm	Measure	Value (MEAN)	Dispersion
Part A: Starting Dose 200 mg QD	Part A: Percentage of Weeks With Platelet Counts >=50,000/μL by Starting Dose Level and Overall	27.92 percentage of weeks	Standard Deviation 29.42
Part A: Starting Dose 400 mg QD	Part A: Percentage of Weeks With Platelet Counts >=50,000/μL by Starting Dose Level and Overall	0.00 percentage of weeks	—
Part A: Starting Dose 300 mg BID	Part A: Percentage of Weeks With Platelet Counts >=50,000/μL by Starting Dose Level and Overall	39.58 percentage of weeks	Standard Deviation 41.3
Part A: Starting Dose 400 mg BID	Part A: Percentage of Weeks With Platelet Counts >=50,000/μL by Starting Dose Level and Overall	28.14 percentage of weeks	Standard Deviation 36.41
Part A: Overall	Part A: Percentage of Weeks With Platelet Counts >=50,000/μL by Starting Dose Level and Overall	28.60 percentage of weeks	Standard Deviation 35.39

Secondary

Part A: Time of Observed Maximum Plasma Concentration (Tmax) of Rilzabrutinib

Plasma samples were collected at specified timepoints to determine tmax of rilzabrutinib.

Time frame: Day 1 of Cycles 1, 2, 3, and 5 (each cycle 28 days)

Arm	Measure	Group	Value (MEDIAN)
Part A: Starting Dose 200 mg QD	Part A: Time of Observed Maximum Plasma Concentration (Tmax) of Rilzabrutinib	Cycle 1 Day 1	1.43 hours (h)
Part A: Starting Dose 400 mg QD	Part A: Time of Observed Maximum Plasma Concentration (Tmax) of Rilzabrutinib	Cycle 2 Day 1	2.00 hours (h)
Part A: Starting Dose 300 mg BID	Part A: Time of Observed Maximum Plasma Concentration (Tmax) of Rilzabrutinib	Cycle 1 Day 1	1.50 hours (h)
Part A: Starting Dose 300 mg BID	Part A: Time of Observed Maximum Plasma Concentration (Tmax) of Rilzabrutinib	Cycle 3 Day 1	1.50 hours (h)
Part A: Starting Dose 400 mg BID	Part A: Time of Observed Maximum Plasma Concentration (Tmax) of Rilzabrutinib	Cycle 1 Day 1	1.50 hours (h)
Part A: Starting Dose 400 mg BID	Part A: Time of Observed Maximum Plasma Concentration (Tmax) of Rilzabrutinib	Cycle 2 Day 1	1.05 hours (h)
Part A: Starting Dose 400 mg BID	Part A: Time of Observed Maximum Plasma Concentration (Tmax) of Rilzabrutinib	Cycle 5 Day 1	1.25 hours (h)

Secondary

Part A: Time to First Platelet Count >=50,000/μL Across All Dose Levels

Time to first platelet count \>=50,000/μL during the treatment period in days was calculated as: (date of first occurrence of platelet count \>=50,000/μL - date of first rilzabrutinib dosing) +1.

Time frame: Up to 24 Weeks

Population: ITT population consisted of all participants who had enrolled into the study. It was prespecified (protocol and SAP) that data will be analyzed for overall across all dose levels, so combined data reported here. Only participants with data collected at specified timepoints are reported.

Arm	Measure	Value (MEAN)	Dispersion
Part A: Starting Dose 200 mg QD	Part A: Time to First Platelet Count >=50,000/μL Across All Dose Levels	27.4 days	Standard Deviation 31.86

Secondary

Part B: Change From Baseline in Idiopathic Thrombocytopenic Purpura Bleeding Scale (IBLS)

The IBLS is a bleeding assessment score. IBLS comprises of 11 sites for female and 10 sites for male, and each site is scored from 0 (none) to 2 (marked bleeding). The total overall score ranges from 0-22, with higher scores indicating higher presence of marked bleeding. For each participant, an IBLS score at each visit was calculated by taking the average across 11 items (10 for male and postmenopausal women) at 9 anatomical sites (8 for male and postmenopausal women). For each participant, a mean IBLS score was also calculated by taking the average across all post-baseline visits during the 24-week treatment period. IBLS average value ranges from 0 to 2. The smaller the IBLS average value is, the healthier the participants are. For change from baseline, negative value indicates an improvement. The baseline value is defined as the last available value before the first dose rilzabrutinib.

Time frame: Baseline and up to 24 weeks

Population: ITT population consisted of all enrolled participants. Only participants with data collected at specified timepoints are reported.

Arm	Measure	Value (MEAN)	Dispersion
Part A: Starting Dose 200 mg QD	Part B: Change From Baseline in Idiopathic Thrombocytopenic Purpura Bleeding Scale (IBLS)	-0.07 score on a scale	Standard Deviation 0.13

Secondary

Part B: Number of Weeks With Platelet Counts >=30,000/μL and Doubling the Baseline

The number of weeks in which participant achieved platelet counts \>=30,000/μL and doubling the baseline in the absence of rescue therapy (platelet counts will be censored for 4 weeks after the use of rescue medication, if given) are summarized here. Baseline is defined as the average of 3 platelet counts: 2 qualified screening platelet counts collected in eCRF and Week 1 (study day 1) platelet count.

Time frame: Up to 24 Weeks

Population: ITT population consisted of all enrolled participants.

Arm	Measure	Value (MEAN)	Dispersion
Part A: Starting Dose 200 mg QD	Part B: Number of Weeks With Platelet Counts >=30,000/μL and Doubling the Baseline	9.3 weeks	Standard Deviation 10.1

Secondary

Part B: Number of Weeks With Platelet Counts >= 50,000/μL or >= 30,000/μL and Doubling the Baseline

The number of weeks in which participant achieved platelet counts with thresholds as: \>=50,000/μL or \>=30,000/μL and doubling the baseline in the absence of rescue therapy (platelet counts will be censored for 4 weeks after the use of rescue medication, if given) are summarized here. Baseline is defined as the average of 3 platelet counts: 2 qualified screening platelet counts collected in electronic case report form (eCRF) and Week 1 (study day 1) platelet count.

Time frame: Up to 24 Weeks

Population: ITT population consisted of all enrolled participants.

Arm	Measure	Value (MEAN)	Dispersion
Part A: Starting Dose 200 mg QD	Part B: Number of Weeks With Platelet Counts >= 50,000/μL or >= 30,000/μL and Doubling the Baseline	9.3 weeks	Standard Deviation 10.1

Secondary

Part B: Percentage of Participants Who Achieved 2 or More Consecutive Platelet Counts

Percentage of participants who achieved 2 or more consecutive platelet counts, separated by at least 5 days, of \>=50,000/μL and an increase of platelet count of \>=20,000/μL from baseline without use of rescue medication in the 4 weeks prior to the latest elevated platelet count are summarized here. Baseline is defined as the average of 3 platelet counts: 2 qualified screening platelet counts collected in eCRF and Week 1 (study day 1) platelet count. 95% CI was based on the Clopper-Pearson exact method.

Time frame: Up to 24 Weeks

Population: ITT population consisted of all enrolled participants.

Arm	Measure	Value (NUMBER)
Part A: Starting Dose 200 mg QD	Part B: Percentage of Participants Who Achieved 2 or More Consecutive Platelet Counts	42.3 percentage of participants

Secondary

Part B: Percentage of Participants Who Received Rescue Medication

Rescue medication is defined as any therapy used to rescue a participant (1 of intravenous immunoglobulin \[IVIG\], high-dose steroids, platelet infusion or anti-D immunoglobulin infusion). Percentage of participants who received rescue medication are summarized here. 95% CI was based on the Clopper-Pearson exact method.

Time frame: Up to 24 Weeks

Population: ITT population consisted of all enrolled participants.

Arm	Measure	Value (NUMBER)
Part A: Starting Dose 200 mg QD	Part B: Percentage of Participants Who Received Rescue Medication	11.5 percentage of participants

Secondary

Part B: Plasma Concentration of Rilzabrutinib

Plasma samples were collected at specified timepoints for evaluation of rilzabrutinib pharmacokinetic (PK) concentrations.

Time frame: Pre-dose and 2 hours post-dose on Days 1, 29, and 57

Population: PK population consisted of all enrolled participants from the safety population who had at least 1 post-baseline PK result.

Arm	Measure	Group	Value (MEAN)	Dispersion
Part A: Starting Dose 200 mg QD	Part B: Plasma Concentration of Rilzabrutinib	Day 1: pre-dose	NA ng/mL	—
Part A: Starting Dose 200 mg QD	Part B: Plasma Concentration of Rilzabrutinib	Day 1: 2 hours post-dose	154.09 ng/mL	Standard Deviation 131.79
Part A: Starting Dose 200 mg QD	Part B: Plasma Concentration of Rilzabrutinib	Day 29: pre-dose	5.07 ng/mL	Standard Deviation 8.61
Part A: Starting Dose 200 mg QD	Part B: Plasma Concentration of Rilzabrutinib	Day 29: 2 hours post-dose	228.67 ng/mL	Standard Deviation 173.68
Part A: Starting Dose 200 mg QD	Part B: Plasma Concentration of Rilzabrutinib	Day 57: pre-dose	26.42 ng/mL	Standard Deviation 90.43
Part A: Starting Dose 200 mg QD	Part B: Plasma Concentration of Rilzabrutinib	Day 57: 2 hours post-dose	331.81 ng/mL	Standard Deviation 151.07

Source: ClinicalTrials.gov · Data processed: Feb 24, 2026

A Study of Rilzabrutinib in Adult Patients With Immune Thrombocytopenia (ITP)

Conditions

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Brief summary

Detailed description

Related papers

Interventions

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Study design

Eligibility

Inclusion criteria

Exclusion criteria

Design outcomes

Primary

Secondary

Countries

Contacts

Participant flow

Recruitment details

Pre-assignment details

Participants by arm

Baseline characteristics

Adverse events

Outcome results

Part A: Number of Participants With Treatment-Emergent Adverse Events (TEAEs) and Treatment Related Treatment-Emergent Adverse Events

Part A: Percentage of Participants Who Achieved 2 or More Consecutive Platelet Counts by Starting Dose Level and Overall

Part B: Number of Participants With Treatment-Emergent Adverse Events and Treatment Related Treatment-Emergent Adverse Events

Part B: Percentage of Participants Who Achieved Platelet Counts >=50,000/μL

Part A: Apparent Total Clearance of the Drug From Plasma After Oral Administration (CL/F) of Rilzabrutinib

Part A: Apparent Volume of Distribution of the Drug After Oral Administration (Vz/F) of Rilzabrutinib

Part A: Area Under the Plasma Concentration-Time Curve From Time Zero to Infinity (AUCinf) of Rilzabrutinib

Part A: Area Under the Plasma Concentration-Time Curve From Time Zero to Last Quantifiable Concentration (AUClast) of Rilzabrutinib

Part A: Change From Baseline to the Average of Post Day 1 Platelet Counts by Dose Level and Overall

Part A: Elimination Half-Life (t1/2) of Rilzabrutinib

Part A: Maximum Observed Plasma Concentration (Cmax) of Rilzabrutinib

Part A: Number of Participants With Idiopathic Thrombocytopenic Purpura/Immune Thrombocytopenia (ITP) Bleeding Assessment Tool (ITP-BAT) Scale by Dose Level

Part A: Number of Weeks With Platelet Counts >=30,000/μL by Starting Dose Level and Overall

Part A: Number of Weeks With Platelet Counts >=50,000/μL by Starting Dose Level and Overall

Part A: Percentage of Participants Who Received Rescue Medication by Dose Levels and Overall

Part A: Percentage of Participants With 4 Out of the Final 8 Platelet Counts >=50,000/μL by Starting Dose Level and Overall

Part A: Percentage of Participants With Grade 2 or Higher Bleeding Event by Dose Level and Overall

Part A: Percentage of Weeks With Platelet Counts >=50,000/μL by Starting Dose Level and Overall

Part A: Time of Observed Maximum Plasma Concentration (Tmax) of Rilzabrutinib

Part A: Time to First Platelet Count >=50,000/μL Across All Dose Levels

Part B: Change From Baseline in Idiopathic Thrombocytopenic Purpura Bleeding Scale (IBLS)

Part B: Number of Weeks With Platelet Counts >=30,000/μL and Doubling the Baseline

Part B: Number of Weeks With Platelet Counts >= 50,000/μL or >= 30,000/μL and Doubling the Baseline

Part B: Percentage of Participants Who Achieved 2 or More Consecutive Platelet Counts

Part B: Percentage of Participants Who Received Rescue Medication

Part B: Plasma Concentration of Rilzabrutinib