CymaBay announces Phase 3 RESPONSE study achieved primary endpoint

CymaBay Therapeutics announced positive topline results from its Phase 3 pivotal RESPONSE study. The study evaluated the safety and efficacy of seladelpar, a potent, selective, orally active delpar or PPARdelta agonist, in development for the treatment of adult patients with primary biliary cholangitis. The registration trial achieved the primary and all key secondary endpoints and supports advancement to regulatory discussions and filing for regulatory approval with the U.S. Food and Drug Administration, the Medicines and Healthcare products Regulatory Agency, and the European Medicines Agency. A total of 61.7% of patients on seladelpar 10 mg met the primary composite endpoint related to serum alkaline phosphatase and bilirubin at 12 months versus 20.0% on placebo. The anti-cholestatic effect of seladelpar was supported by the normalization of alkaline phosphatase at 12 months in 25.0% of patients on seladelpar vs. zero on placebo. The least-squares mean percent reduction in alkaline phosphatase at 12 months was 42.4% in the seladelpar group vs. 4.3% in the placebo group. Seladelpar treatment compared to placebo also demonstrated a statistically significant reduction in pruritus, or itch, after 6 months of treatment. Seladelpar-treated patients with a baseline Numerical Rating Scale greater than or equal to 4 had a least-square mean reduction of 3.2 points in pruritus NRS compared to 1.7 points for patients in the placebo group. Overall, safety was comparable between placebo and seladelpar groups and was consistent with previous studies. Treatment-emergent adverse events, serious adverse events, and patient discontinuations were generally balanced across the treatment and placebo arms. There were no treatment-related serious adverse events in the study. Seladelpar’s tolerability profile appeared favorable and consistent with previous studies.