Rigel Pharmaceuticals Plans Not to File Fostamatinib sNDA Following FDA Feedback

Rigel Pharmaceuticals decided to not file a supplemental New Drug Application (sNDA) for fostamatinib in the treatment of patients with warm autoimmune hemolytic anemia, an autoimmune disorder that includes premature destruction of healthy red blood cells.

The company decision follows FDA feedback. The phase 3 trial results also did not help make the case for this drug, which did not demonstrate statistical significance in durable hemoglobin response in the overall study population.

Fostamatinib is FDA-approved as Tavalisse (fostamatinib disodium hexahydrate) for the treatment of adult patients with chronic immune thrombocytopenia who have had an insufficient response to a previous treatment.

Tavalisse is an oral spleen tyrosine kinase inhibitor.