NCT03395210

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
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 86 (actual)
• Sponsor: Principia Biopharma, a Sanofi Company · Industry
• Sex: All
• Age: 18 Years – 80 Years
• Healthy volunteers: Not accepted

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.

Conditions

• Immune Thrombocytopenia

Interventions

Type	Name	Description
DRUG	Rilzabrutinib	BTK inhibitor

Timeline

• Start date: 2018-03-22
• Primary completion: 2023-01-31
• Completion: 2025-12-11
• First posted: 2018-01-10
• Last updated: 2026-02-23
• Results posted: 2025-11-14

Locations

31 sites across 8 countries: United States, Australia, Bulgaria, Canada, Czechia, Netherlands, Norway, United Kingdom

Regulatory

• FDA-regulated drug study