Gilead's Livdelzi meets primary endpoint in Phase 3 IDEAL trial in primary biliary cholangitis

What's the deal? On 5 November 2026, Gilead Sciences reported positive topline results from the Phase 3 IDEAL trial of Livdelzi (seladelpar) in adults with primary biliary cholangitis (PBC), a chronic autoimmune disease in which the bile ducts of the liver become inflamed and damaged, which can progress to cirrhosis and liver failure.

Why it matters: The double-blind, placebo-controlled study evaluated Livdelzi as a second-line treatment in patients whose disease remained inadequately controlled — defined as alkaline phosphatase (an enzyme whose level reflects bile-duct damage) at 1–1.67 times the upper limit of normal — despite at least 12 months of the standard therapy ursodeoxycholic acid, or who could not tolerate that drug. At week 52, 75.4% (49/65) of patients taking Livdelzi reached the primary endpoint of alkaline phosphatase normalisation (a return to normal levels plus a further drop of at least 15%), versus 16.1% (5/31) of patients on placebo. Serious adverse events were reported in 3.1% of the Livdelzi group and 12.9% of the placebo group, with none judged related to the study drug. Livdelzi, which Gilead gained through its 2024 acquisition of CymaBay, is already approved for PBC; Gilead said it is in discussions with global regulators about these new results, which support earlier treatment initiation in patients with lower baseline enzyme elevations.

Read more: Gilead Sciences, 5 November 2026