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News Details View All News Mirum Pharmaceuticals Announces Primary Endpoint Met in Phase 3 EXPAND Study of LIVMARLIⓇ ( maralixibat ) in Ultra - Rare Cholestatic Liver Diseases October 12 , 2026 - Maralixibat demonstrated a statistically significant reduction in cholestatic pruritus compared with placebo ( p = 0.0004 ) , and a 69 % reduction in serum bile acids versus placebo ( p < 0.0001 ) - In patients with biliary atresia , maralixibat demonstrated a statistically significant reduction in cholestatic pruritus compared with placebo ( p = 0.0002 ) - Mirum plans U.S. SNDA submission in the first half of 2027 based on positive EXPAND results - Mirum to host conference call to discuss topline results today , October 12 , at 8:30 a.m. ET FOSTER CITY , Calif .-- ( BUSINESS WIRE ) -- Mirum Pharmaceuticals , Inc. ( Nasdaq : MIRM ) , a leading rare disease company , today announced topline results from the Phase 3 EXPAND study evaluating LIVMARLIⓇ ( maralixibat ) for the treatment of cholestatic pruritus in patients aged 6 months or older with ultra - rare cholestatic liver diseases , including biliary atresia . The study met its primary endpoint and achieved statistical significance across all five prespecified secondary endpoints , including the three endpoints in patients with biliary atresia and a native liver . The Phase 3 EXPAND study enrolled 52 patients , including 46 pediatric and six adult patients , who were randomized during the 20 - week double - blind period to treatment with maralixibat 285 µg / kg twice daily ( BID ) or placebo . Treatment with maralixibat demonstrated a statistically significant improvement in pruritus compared with placebo in the primary analysis population of pediatric patients . Maralixibat resulted in a mean 1.81- point improvement from baseline in average worst - daily ItchRO ( Obs ) severity score during Weeks 13-20 compared with a 0.83 - point improvement for placebo , corresponding to a placebo - adjusted treatment difference of 0.98 points ( p = 0.0004 ) . Maralixibat also resulted in a 70.1 % reduction from baseline in serum bile acids ( SBA ) , compared with 3.5 % for placebo , corresponding to a 69.0 % treatment effect versus placebo ( p < 0.0001 ) . Key efficacy data from the Phase 3 EXPAND study are presented below in the Efficacy Results table . Safety findings in EXPAND were consistent with prior clinical experience with maralixibat and no new safety signals were observed . Key safety data from the Phase 3 EXPAND study are presented below in the Safety Summary table . " These results are especially important because patients with ultra - rare cholestatic liver diseases continue to face a significant burden from pruritus , " said Rob Myers , M.D. , Chief Medical Officer at Mirum Pharmaceuticals . " The improvements in pruritus and reductions in serum bile acids observed in EXPAND reinforce the potential for maralixibat to address this unmet need and benefit a broader population of patients living with ultra - rare cholestatic liver diseases . " " Cholestatic pruritus can be relentless and profoundly disruptive for people living with ultra - rare cholestatic liver diseases , yet treatment options remain limited , " said Jennifer Vittorio , M.D. , FAASLD , Associate Professor of Pediatrics and Medical Director , Pediatric Liver Transplantation , NYU Langone