This is 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 enrolls patients with ITP who are refractory or relapsed with no available and approved therapeutic options. Eligible patients have 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 is 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 is allowed to up-titrate their dose after 28 days of PRN1008 therapy, if they do not experience a platelet response or a dose-limiting toxicity (DLT) at the last dose level. Patients who respond to PRN1008 per protocol may enter a long term-extension.~Part B of the study will include approximately 25 patients with ITP who have relapsed or have an insufficient response to prior therapies. Eligible patients will have a platelet count <30,000/µL on two occasions no less than 7 days apart, within 15 days before treatment begins and a platelet count of ≤35,000/µL on Study Day 1 (SD1). The study consists of a 28-day screening period, 24-week active treatment period, and a long-term extension. After the last dose of PRN1008 there will be a 4-week safety follow-up period.
This is 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 has been completed. Part B treatment dose is 400 mg twice daily.