Rigel Pharmaceuticals announced positive data from the Phase 3 study of fostamatinib for the treatment of chronic or persistent immune thrombocytopenia (ITP) in adults.

The study was the first of two identical, multicenter, randomized, double-blind, placebo-controlled Phase 3 trials from the FIT clinical program evaluating the efficacy and safety of fostamatinib in ITP patients with platelet counts consistently below 30,000/uL of blood. Patients received either fostamatinib or placebo twice a day for up to 24 weeks. The primary efficacy endpoint was stable response, defined as achieving platelet counts ≥50,000/uL of blood for at least 4 of the last 6 clinic visits. 

Related Articles

The trial met its primary endpoint, showing that 18% of patients treated with fostamatinib achieved a stable platelet response vs. 0% in the placebo group (P=0.0261). A platelet count increase from a median of 16,000/uL at baseline to a median of >100,000/uL at Week 24 was achieved in patients treated with fostamatinib. Patients typically had an increase in platelet counts to a level >50,000/uL within the initial weeks of treatment, an indication for a viable ITP treatment. The study found fostamatinib to be generally well-tolerated, with gastrointestinal-related adverse events as the most frequent drug reactions.

Patients who achieved the primary endpoint from this study were subsequently enrolled in the ongoing, long-term Phase 3 extension study. Upon successful completion of the extension study and the second FIT Phase 3 study, the company intends to submit a New Drug Application (NDA) for fostamatinib with the FDA in the first quarter of 2017.

Fostamatinib is an oral spleen tyrosine kinase (SYK) inhibitor.

For more information call (650) 624–1100 or visit Rigel.com.