LIVMARLI (maralixibat) - (EXPAND)

October 12, 2026: Mirum Pharmaceuticals (NASDAQ: MIRM) reported positive topline results from the Phase 3 EXPAND trial of LIVMARLI (maralixibat) in cholestatic pruritus in patients aged 6 months and older with ultra-rare cholestatic liver diseases, including biliary atresia. The 52-patient randomized, double-blind, placebo-controlled study met its primary endpoint and all five prespecified secondary endpoints.

In pediatric patients, maralixibat improved worst-daily ItchRO(Obs) score by 1.81 points from baseline versus 0.83 for placebo, for a placebo-adjusted difference of 0.98 (p=0.0004). Serum bile acids fell 70.1% versus 3.5% with placebo, a 69.0% treatment effect (p<0.0001), and days with pruritus improvement were 86.0% versus 49.1% (p=0.0008).

In the biliary atresia with native liver subgroup, ItchRO(Obs) improved by 2.16 versus 1.01, for a treatment difference of 1.15 (p=0.0002); serum bile acids fell 75.5% versus 9.0% (treatment effect 73.1%, p<0.0001); and days with pruritus improvement were 96.4% versus 52.2% (p=0.0045).

Safety was consistent with prior maralixibat experience, with no new safety signals. Diarrhea was more common with maralixibat (64.0% vs 11.1%). Mirum plans a U.S. sNDA submission in 1H 2027 based on EXPAND.