Rigel Pharmaceuticals has ended enrolment for both studies in the FIT Phase 3 clinical programme of fostamatinib drug, its oral spleen tyrosine kinase (SYK) inhibitor, in immune thromboycytopenic purpura (ITP) disease.
While the first study of this programme completed enrolment at the end of January, the second study has just finished this.
The first study results are expected by mid-2016, and results for the second study are expected shortly afterwards.
The FIT phase 3 clinical programme comprises two similar studies with around 75 patients in each.
Patients were diagnosed with constant or chronic ITP, and had blood platelet counts consistently below 30,000 per microliter of blood.
Patients will remain on treatment for up to 24 weeks.
The primary efficacy endpoint of the programme is a stable platelet response by the last week with platelet counts at or above 50,000 per microliter of blood for at least four of the final six qualifying blood draws.
The patients with ITP experience attack on their immune system that destroys the body's own blood platelets, which play an active role in blood clotting and healing.
ITP patients can suffer unusual bruising, bleeding and fatigue due to low platelet counts.
Currently, steroids, blood platelet production boosters (TPOs) and splenectomy therapies are available for ITP.
Rigel expects that its fostamatinib drug could address the autoimmune basis of the disease.
Research has shown that inhibiting SYK enzyme with fostamatinib could reduce destruction of red blood cells.
In the early part of this year, the company initiated a phase 2 clinical trial in a second autoimmune disorder of the blood, autoimmune hemolytic anemia (AIHA).
The clinical trial aims to assess the safety and efficacy of fostamatinib in patients with chronic AIHA, which affects around 40,000 people in the US.
No approved treatment options currently exist for AIHA patients.
Image: Petechiae, or small bruise-like markings, may occur in ITP. Photo: courtesy of User:Hektor.