GSK has shared the data behind its phase 3 liver disease win, revealing patients on linerixibat reported reductions in itching that began after two weeks and persisted through the 24-week primary endpoint.
The British Big Pharma reported the trial met its primary endpoint in November without providing any details. GSK filled in the gaps Thursday, May 8 using the European Association for the Study of the Liver Congress 2025 to share the numbers behind the primary endpoint hit and provide a first look at the effect of the IBAT inhibitor on secondary endpoints.
Investigators enrolled 238 people with the liver disease primary biliary cholangitis and cholestatic pruritus, a medical term for relentless itch. After 24 weeks of oral dosing, scores on a 10-point itch scale fell 2.86 points in the linerixibat arm and 2.15 points in the placebo cohort.
The difference between the two arms was statistically significant, achieving the trial’s primary endpoint. After two weeks, there was a statistically significant 0.71-point difference between the control and treatment groups. The level of itch reduction, which was 1.78 points on linerixibat at Week 2, deepened over time, but the difference versus placebo was almost unchanged at the primary endpoint.
GSK reported a significant improvement in itch-related sleep interference. More patients on linerixibat than placebo—56% versus 43%—had a three-point or greater improvement in itch, which GSK said is clinically meaningful. Linerixibat was also associated with more four-point or greater improvements, beating placebo on that endpoint by 41% to 29%.
Diarrhea was more common on linerixibat, affecting 61% of patients versus 18% of people on placebo, and 4% of people discontinued the study drug because of the gastrointestinal side effect. The rate of abdominal pain was also higher in recipients of linerixibat.
The results set the bar for GSK’s rivals. Mirum Pharmaceuticals is using the 10-point ItchRO scale in a phase 2b trial of its IBAT inhibitor, volixibat. The biotech reported placebo-adjusted changes of around 2.3 points at an interim analysis.
GSK has a head start on the competition. The drugmaker is aiming (PDF) to win approval for linerixibat in the U.S. in the second half of the year and secure green lights to sell the product in China, the EU and Japan in 2026.