The results from the initial trial are anticipated in the middle of this year, with the results from the second study expected soon thereafter.
The FIT program features two similar studies of 75 patients each, who will be diagnosed with persistent or chronic ITP, and have blood platelet counts below 30,000 per microliter of blood.
The patients will be treated for 24 weeks. The primary efficacy endpoint of the program is a stable platelet response by week 24 with platelet counts at or above 50,000 per microliter of blood for about four of the last six qualifying blood draws.
Rigel has secured orphan drug designation from the US Food and Drug Administration for fostamatinib, oral spleen tyrosine kinase inhibitor, to treat patients with ITP.
The company said in patients with ITP, the immune system attacks and destroys the body’s own blood platelets, which play a key role in blood clotting and healing.
ITP patients can experience extraordinary bruising, bleeding and fatigue due to low platelet counts. The existing therapies for ITP are steroids, blood platelet production boosters and splenectomy.
Rigel Pharmaceuticals is engaged in the discovery and development of novel, targeted drugs in the therapeutic areas of immunology, oncology and immuno-oncology.
Apart from fostamatinib, Rigel is also undertaking a phase 2 clinical trial for IgA nephropathy. A phase 2 clinical trial for autoimmune hemolytic anemia is planned to be undertaken laster this year.