Mirum announces primary endpoint met in VISTAS Phase 2b study of volixibat

Mirum Pharmaceuticals (MIRM) announced the primary endpoint was met in the VISTAS Phase 2b study evaluating volixibat, an investigational oral ileal bile acid transporter, IBAT, inhibitor, in patients with primary sclerosing cholangitis, PSC. The VISTAS Phase 2b study included 158 patients with PSC who were assigned to either a primary analysis cohort or a secondary analysis cohort based on itch severity at baseline, as measured by the Adult Itch Reported Outcome scale. The results of the VISTAS Phase 2b study support the potential for volixibat to become the first treatment for cholestatic pruritus in patients with PSC. In the primary analysis cohort, treatment with volixibat demonstrated a robust 2.72 point improvement in pruritus and a placebo-adjusted difference of 1.64 points in the primary endpoint, as measured by the Adult ItchRO scale, reflecting change from baseline to the average of the last 12 weeks of treatment. Statistically significant improvements in pruritus were observed within two weeks of treatment and were also observed in the secondary cohort of patients with mild itch at baseline. Key efficacy data from the VISTAS Phase 2b study are presented below in the Change from Baseline table.