Volixibat Improves Sleep in Liver Disease Trial
Phase 2b VISTAS data show the investigational drug improved sleep versus placebo in adults with primary sclerosing cholangitis and cholestatic pruritus.
Updated on Nov. 5, 2026 in Sleep Disorders
Mirum Pharmaceuticals' investigational drug volixibat improved sleep compared with placebo in adults with primary sclerosing cholangitis and cholestatic pruritus in the phase 2b VISTAS trial. Investigator Christopher Bowlus presented the sleep and fatigue analysis at The Liver Meeting 2026.
Why it matters
Pruritus, or severe itch, is a common and disruptive symptom in this liver disease, and sleep disturbance is a major contributor to patients' reduced quality of life. The findings suggest that relieving itch may also translate into meaningful gains in sleep for these patients.
The trial enrolled 111 participants, with sleep improving by an LS mean change of -6.47 on volixibat versus -0.78 on placebo (P = .0011). Fatigue differences between arms were not statistically significant (P = .13), and whether sleep gains occur independently of itch relief remains unresolved.
The players
Mirum Pharmaceuticals
Mirum Pharmaceuticals is a biopharmaceutical company developing treatments for rare liver diseases, and it is the sponsor of volixibat.
Christopher Bowlus
Christopher Bowlus is a hepatologist at the University of California Davis who presented the VISTAS sleep and fatigue analysis.
The details
Investigators assessed fatigue and sleep through Week 28 using validated PROMIS health-related quality of life measures. Pruritus responders, defined as those with a reduction of at least 2 points in Adult ItchRO score, showed greater sleep and fatigue improvement than nonresponders regardless of treatment assignment.
Timeline
August 2026: FDA granted volixibat Breakthrough Therapy and Orphan Drug designations.
November 5, 2026: Christopher Bowlus presented the VISTAS analysis at The Liver Meeting 2026.
First half of 2027: Mirum plans further FDA discussions and a potential NDA submission.
Big Picture
Volixibat received FDA Breakthrough Therapy designation in August 2026, and the VISTAS sleep and fatigue findings add patient-reported outcome evidence beyond the primary itch endpoint. The data extend the drug's clinical profile into quality-of-life measures that the designation program is designed to accelerate.
For patients with primary sclerosing cholangitis, relieving itch may also improve nightly rest and daytime energy, though these benefits are not yet approved treatment outcomes. Diarrhea was common on volixibat, affecting 40.3% of participants versus 8.6% on placebo, so patients should weigh that side effect when considering future therapy.
The takeaway
Improving itch in liver disease may bring broader benefits to sleep and fatigue, a link worth tracking as volixibat moves toward regulatory review. Patients should discuss sleep problems with their clinicians, since treatment options are still under investigation.
What happens next
Mirum plans further discussions with the FDA and a potential NDA submission for volixibat in the first half of 2027.
Further reading
For more on how sleep is affected by chronic conditions, see Sleep Disorders.
