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Immune ThrombocytopeniaPhase 2NCT03395210

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

A Phase 2 study testing Rilzabrutinib in people with Immune Thrombocytopenia, run by Principia Biopharma, a Sanofi Company at 31 sites in 8 countries.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
Search all trials

Trial 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. Read more about this study

Who is it for?
Ages 18 to 80 years
Conditions the study is for
Immune Thrombocytopenia
What is being tested?
Rilzabrutinib
Could I receive a placebo?
No, everyone receives an active treatment
How many people
86 participants
Where
31 sitesin 8 countries
Study dates
22 Mar 2018to 11 Dec 2025
Phase
Phase 2
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 80 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

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

Who cannot join

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

Trial locations and contacts

31 sites in 8 countries.

31 sites in 8 countries

United States8 sites

  • RCCA MC LLC- Site Number : 1091

    Bethesda, Maryland, 20817-1915

  • Massachusetts General Hospital Cancer Center- Site Number : 1092

    Boston, Massachusetts, 02114-2603

  • Beth Israel Deaconess Medical Center- Site Number : 1099

    Boston, Massachusetts, 02215

  • Pitt County Memorial Hospital- Site Number : 1095

    Greenville, North Carolina, 27834

  • Mid Michigan Medical Center- Site Number : 1086

    Midland, Michigan, 48670

  • New York Presbyterian Hospital/Weill Cornell Medical Center- Site Number : 1097

    New York, New York, 10021

  • Bleeding and Clotting Disorders Institute- Site Number : 1087

    Peoria, Illinois, 61614-2868

  • Seattle Cancer Care Alliance Site Number : 1098

    Seattle, Washington, 98109-4405

Other trials in United States

Australia6 sites

  • Investigational Site Number : 105

    Canberra, Australian Capital Territory, 2605

  • Investigational Site Number : 101

    Clayton, Victoria, 3168

  • Investigational Site Number : 106

    Parkville, Victoria, 3050

  • Investigational Site Number : 103

    Perth, Western Australia, 6005

  • Investigational Site Number : 104

    Sydney, New South Wales, 2139

  • Investigational Site Number : 102

    Woolloongabba, Queensland, 4102

Other trials in Australia

Czechia4 sites

  • Investigational Site Number : 431

    Brno, 62500

  • Investigational Site Number : 433

    Hradec Králové, 50005

  • Investigational Site Number : 434

    Ostrava - Poruba, 70852

  • Investigational Site Number : 432

    Prague, 12808

Other trials in Czechia

United Kingdom4 sites

  • Investigational Site Number : 984

    Birmingham, B15 2GW

  • Investigational Site Number : 981

    Leicester, Leicestershire, LE1 5WW

  • Investigational Site Number : 983

    London, London, City of, E1 2ES

  • Investigational Site Number : 980

    London, London, City of, W12 0HS

Other trials in United Kingdom

Bulgaria3 sites

  • Investigational Site Number : 213

    Pleven, 5800

  • Investigational Site Number : 214

    Sofia, 1431

  • Investigational Site Number : 211

    Varna, 9010

Other trials in Bulgaria

Canada2 sites

  • Investigational Site Number : 1162

    Montreal, Quebec, H3A 1A1

  • Investigational Site Number : 1161

    Toronto, Ontario, M5B 1W8

Other trials in Canada

Netherlands2 sites

  • Investigational Site Number : 727

    Rotterdam, 3015 GD

  • Investigational Site Number : 728

    The Hague, 2545 CH

Other trials in Netherlands

Norway2 sites

  • Investigational Site Number : 542

    Bergen, N-5021

  • Investigational Site Number : 541

    Grålum, 1714

Other trials in Norway

About this study

Official title: 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

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.

Read the 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.

Being tested
Rilzabrutinib
Keywords
ITP
Medical subject headings
Purpura, Thrombocytopenic, Idiopathic

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • RilzabrutinibDrug

    Also called PRN1008

    BTK inhibitor

Study groups in NCT03395210
Study groupRoleWhat they receive
Rilzabrutinib (PRN1008) DailyExperimentalPart A approximately 60 patients: Up to 24 weeks open-label treatment with PRN1008 400mg BID; safety and dose evaluation. Patients who respond to PRN1008 per protocol may enter a long-term extension. Part B approximately 25 patients: Up to 24 weeks open-label treatment with PRN1008 400mg BID; safety and dose evaluation. Patients who respond to PRN1008 per protocol may enter a long-term extension
Receives: Drug: Rilzabrutinib

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. 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.

    Measured: Up to 24 Weeks

  2. 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.

    Measured: Up to 24 Weeks

  3. 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.

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

  4. 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.

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

Secondary outcomes (22)

  1. 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.

    Measured: Up to 24 Weeks

  2. 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.

    Measured: Up to 24 Weeks

  3. 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.

    Measured: Baseline and up to 24 Weeks

  4. 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.

    Measured: Up to 24 Weeks

  5. 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.

    Measured: Up to 24 Weeks

  6. 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.

    Measured: Up to 24 Weeks

  7. 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.

    Measured: Up to 24 Weeks

  8. 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.

    Measured: Up to 24 Weeks

  9. 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.

    Measured: Up to 24 Weeks

  10. 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.

    Measured: Up to 24 Weeks

  11. 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.

    Measured: Baseline and up to 24 weeks

  12. 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.

    Measured: Up to 24 Weeks

  13. 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.

    Measured: Up to 24 Weeks

  14. 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.

    Measured: Up to 24 Weeks

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

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

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

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

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

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

  17. 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.

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

  18. 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.

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

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

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

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

  20. 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.

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

  21. 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.

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

  22. Part B: Plasma Concentration of Rilzabrutinib

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

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

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted10 Jan 2018
  2. Study start22 Mar 2018
  3. Primary completion31 Jan 2023
  4. Study completion11 Dec 2025

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 2
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Sequential
Masking
None (open label)
Enrolment
86 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT03395210
Sponsor's protocol ID
DFI17124
Other IDs
PRN1008-010, U1111-1260-4044, 2023-509397-39, 2023
Status last verified
Feb 2026
First submitted
22 Dec 2017
Last updated
23 Feb 2026
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
Yes: Qualified researchers may request access to patient level data and related study documents including the clinical study report, study protocol with any amendments, blank case report form, statistical analysis plan, and dataset specifications. Patient level data will be anonymized and study documents will be redacted to protect the privacy of trial participants. Further details on Sanofi's data sharing criteria, eligible studies, and process for requesting access can be found at: https://vivli.org

Publications

  • Cooper N, Jansen AJG, Bird R, Mayer J, Sholzberg M, Tarantino MD, Garg M, Ypma PF, McDonald V, Percy C, Kostal M, Goncalves I, Bogdanov LH, Gernsheimer TB, Diab R, Yao M, Daak A, Kuter DJ. Efficacy and Safety Results With Rilzabrutinib, an Oral Bruton Tyrosine Kinase Inhibitor, in Patients With Immune Thrombocytopenia: Phase 2 Part B Study. Am J Hematol. 2025 Mar;100(3):439-449. doi: 10.1002/ajh.27539. Epub 2025 Jan 22.

    PubMed 39844469

  • Kuter DJ, Mayer J, Efraim M, Bogdanov LH, Baker R, Kaplan Z, Garg M, Trneny M, Choi PY, Jansen AJG, McDonald V, Bird R, Gumulec J, Kostal M, Gernsheimer T, Ghanima W, Daak A, Cooper N. Long-term treatment with rilzabrutinib in patients with immune thrombocytopenia. Blood Adv. 2024 Apr 9;8(7):1715-1724. doi: 10.1182/bloodadvances.2023012044.

    PubMed 38386978

  • Kuter DJ, Efraim M, Mayer J, Trneny M, McDonald V, Bird R, Regenbogen T, Garg M, Kaplan Z, Tzvetkov N, Choi PY, Jansen AJG, Kostal M, Baker R, Gumulec J, Lee EJ, Cunningham I, Goncalves I, Warner M, Boccia R, Gernsheimer T, Ghanima W, Bandman O, Burns R, Neale A, Thomas D, Arora P, Zheng B, Cooper N. Rilzabrutinib, an Oral BTK Inhibitor, in Immune Thrombocytopenia. N Engl J Med. 2022 Apr 14;386(15):1421-1431. doi: 10.1056/NEJMoa2110297.

    PubMed 35417637

  • Del Pozo Martin Y. 2021 ASH annual meeting. Lancet Haematol. 2022 Feb;9(2):e92-e93. doi: 10.1016/S2352-3026(21)00384-7. Epub 2021 Dec 16. No abstract available.

    PubMed 34922648

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing Rilzabrutinib in people with Immune Thrombocytopenia, run by Principia Biopharma, a Sanofi Company at 31 sites in 8 countries.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 2 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 23 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 31 sites in United States, Australia, Czechia, United Kingdom, Bulgaria and 3 more countries. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 14 Nov 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Part A: Percentage of Participants Who Achieved 2 or More Consecutive Platelet Counts by Starting Dose Level and Overall (time frame: Up to 24 Weeks). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT03395210, which also lists 4 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 23 Feb 2026.

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