Mirum's LIVMARLI meets primary endpoint in Phase 3 EXPAND study for cholestatic liver diseases

What's the deal? On 12 October 2026, Mirum Pharmaceuticals announced that the Phase 3 EXPAND study of LIVMARLI (maralixibat) met its primary endpoint. In patients with biliary atresia, a rare liver disease of babies in which bile ducts are absent or blocked, maralixibat produced a statistically significant reduction in cholestatic pruritus (severe itch caused by bile building up in the blood) compared with placebo (p=0.0002). The study also evaluated maralixibat in other ultra-rare cholestatic liver diseases with chronic itch, where bile flow from the liver is impaired. Secondary measures included changes in serum bile acid levels and days with pruritus improvement.

Why it matters: LIVMARLI is an oral drug that blocks the ileal bile acid transporter, keeping bile acids from being reabsorbed into the blood, which drives the itch. It is already approved for two other rare liver diseases (Alagille syndrome and progressive familial intrahepatic cholestasis), and this readout supports a potential third indication in biliary atresia — a disease with virtually no approved drug treatments. Biliary atresia is normally treated with surgery (the Kasai procedure) and often progresses to liver transplant, so an approved medicine that controls symptoms could change clinical management.

Read more: Mirum Pharmaceuticals, 12 October 2026 · Fierce Pharma, 12 October 2026