Mirum Pharmaceuticals' Volixibat Meets Primary Endpoint in PSC Study
Mirum Pharmaceuticals announced that its VISTAS Phase 2b study of volixibat, an investigational IBAT inhibitor, met its primary endpoint in patients with primary sclerosing cholangitis (PSC). Volixibat demonstrated a robust and statistically significant 2.72 point improvement in pruritus compared to placebo, supporting its potential as the first treatment for cholestatic pruritus in PSC patients. The safety profile was consistent with known IBAT inhibition effects, primarily gastrointestinal adverse events and liver enzyme elevations. The company plans a pre-NDA meeting with the FDA in summer 2026, with an NDA submission targeted for the second half of 2026, and expects topline data from its VANTAGE Phase 2b study in PBC in Q1 2027.
Key Highlights
- Volixibat met primary endpoint in VISTAS Phase 2b study for primary sclerosing cholangitis (PSC).
- Volixibat showed a 2.72 point pruritus improvement (vs. -1.08 placebo) in primary analysis cohort.
- Placebo-adjusted difference of 1.64 points in pruritus was statistically significant (p<0.0001).
- 55.6% of volixibat patients achieved ">=2 point itch reduction vs. 26.3% for placebo.
- Safety profile consistent with IBAT inhibition, mainly GI adverse events and liver enzyme elevations.
- Pre-NDA meeting with FDA scheduled for summer 2026 for volixibat in PSC.
- NDA submission for volixibat in PSC planned for the second half of 2026.
- Topline data from VANTAGE Phase 2b study in PBC expected in Q1 2027.