Maralixibat Side Effects and What Clinicians Should Know From EXPAND
Mirum Pharmaceuticals' maralixibat (Livmarli) showed gastrointestinal side effects in the phase 3 EXPAND trial for ultra-rare cholestatic liver diseases. Diarrhea occurred in 64.0% of patients vs 11.1% on placebo, with other adverse events including abdominal pain and increased alanine aminotransferase. The drug improved pruritus symptoms significantly. Mirum plans to submit a supplemental new drug application in 2027 based on EXPAND results.
How this was made
The 30-second read
Why it matters
Phase 3 data provide the first peer‑reviewed safety numbers; GI adverse events are common, but itch reduction is statistically significant, shaping future regulatory and commercial prospects.
Market read
New phase 3 data could affect Mirum's stock and peers in the rare‑disease biotech space, but the mixed safety profile tempers immediate upside.
What to watch
Future supplemental NDA filing in 2027 and lack of peer‑reviewed data may delay commercial uptake.
Background
The article summarizes an interview about the safety and efficacy of marixibat (Livmarli) from the phase 3 EXPAND trial in ultra‑rare cholestatic liver diseases.
Ticker impact
Mirum Pharmaceuticals reported phase 3 EXPAND trial results for Livmarli (marixibat), including safety data and efficacy endpoints.
potential modest downside as safety concerns weigh against efficacy benefits
Safety profile may temper enthusiasm despite positive itch‑RO improvement; market may price in risk of slower uptake.
Market effects
adds data to the IBAT inhibitor space, may influence peer biotech valuations
U.S. biotech sector sees mixed reaction; no broader regional effect
limited to niche rare‑disease therapeutics market
Counterpoint
Investors could view the strong itch‑RO improvement as outweighing GI side‑effects, supporting a buy on upside potential.
Key entities
- CompanyMirum Pharmaceuticals
Developer of Livmarli (marixibat) and sponsor of the EXPAND trial.
- PersonJennifer Vittorio, MD
Medical director of pediatric liver transplantation at NYU Langone Health, providing clinical commentary.
