Rigel's fostamatinib misses in Phase II for IgA nephropathy

Rigel Pharmaceuticals Inc. (NASDAQ:RIGL) said Tavalisse fostamatinib missed the primary endpoint in a Phase II trial to treat IgA nephropathy. Twice-daily 100 and 150 mg doses of fostamatinib each failed to significantly reduce mean proteinuria from baseline to week 24 as measured by spot urine protein/creatinine ratio (sPCR) vs. placebo (577 and 158 mg/g, respectively, vs. 177 mg/g, p-values not disclosed). The double-blind, international trial enrolled 76 patients with IgA nephropathy verified by biopsy and proteinuria greater than 500 mg/day at baseline.

Rigel saw a non-significant trend favoring fostamatinib over placebo in reducing proteinuria in a prespecified subgroup of patients with more advanced disease. In 45 patients with baseline proteinuria greater than 1 g/day, low- and high-dose fostamatinib non-significantly reduced median proteinuria from baseline to week 24 by 720 and 803 mg/g, respectively, vs. 177 mg/g for placebo...