Oral SYK Inhibitor for Autoimmune Hemolytic Anemia:
- Autoimmune hemolytic anemia (AIHA) is a rare, serious blood disorder in which the immune system produces antibodies that result in the destruction of the body's own red blood cells.
- AIHA affects approximately 40,000 adult patients in the US and can be a severe, debilitating anemia. To date, there are no approved therapies for AIHA, despite the tremendous medical need that exists for these patients.
- Rigel's fostamatinib disodium hexahydrate (fostamatinib) is an oral spleen tyrosine kinase (SYK) inhibitor. Pre-clinical research with fostamatinib in AIHA showed that inhibiting SYK may ameliorate red blood cell destruction.
- On January 31, 2018, the FDA granted Orphan Drug designation to fostamatinib for the treatment of patients with AIHA.
- In Rigel’s SOAR Phase 2 clinical trial evaluating the safety and efficacy of fostamatinib in patients with warm AIHA who did not receive a meaningful benefit from at least one previous treatment, 9 out of 21 evaluable patients (43%) achieved the primary efficacy endpoint at week 24. One additional patient was a late responder at week 30, for a total of 10 out 21 evaluable patients (48%).
- In May 2019, Rigel enrolled the first patient in a pivotal Phase 3 clinical trial of fostamatinib in warm AIHA. The clinical trial protocol calls for approximately 80 patients in a 24-week study with topline results projected for early 2021.