Gilead posts long-term data showing sustained liver marker normalization with Livdelzi

Gilead Sciences (NASDAQ:GILD) released new results from a post hoc analysis of its open-label Phase 3 ASSURE study, demonstrating that its approved drug Livdelzi (seladelpar) achieved high and sustained rates of normalization in a key biomarker of liver disease progression.

The Foster City, California-based biopharmaceutical company presented the clinical data package at the European Association for the Study of the Liver (EASL) Congress 2026 in Barcelona, Spain.

The findings focus on a specific patient cohort living with primary biliary cholangitis (PBC)—a chronic, progressive autoimmune disease of the bile ducts that can lead to liver failure—who continue to exhibit elevated alkaline phosphatase (ALP) levels despite receiving baseline, first-line therapies.

The clinical analysis specifically tracked 50 participants who entered the trial with moderately elevated baseline ALP levels, defined between 1 and 1.67 times the upper limit of normal (ULN).

This sub-population has historically been underrepresented in traditional randomized clinical trials.

The data showed that 83% of evaluable participants achieved composite ALP normalization—defined as an overall ALP level at or below 1×ULN alongside at least a 15% absolute reduction—after 12 months of daily treatment.

The therapeutic response remained durable over an extended window, with 74% of the evaluable group maintaining the target normalization endpoint at the 24-month mark.

Investigators noted that mean ALP levels dropped substantially from baseline and remained lowered throughout the long-term follow-up period.

Parallel improvements were recorded in secondary markers of cholestasis, such as gamma-glutamyl transferase (GGT), while total bilirubin levels remained stable overall.

The evaluated group included individuals carrying established risk factors for rapid liver decline, including younger age at initial diagnosis and compensated cirrhosis.

Up to two years of continuous clinical observation indicated that Livdelzi was generally well tolerated, with zero recorded treatment discontinuations due to adverse events and no new safety signals emerging during the extension phase.

In a separate exploratory tracking initiative across the wider ASSURE study population, 85% of the 91 participants who achieved an initial biochemical response at 12 months maintained or showed descriptive improvements in liver stiffness measurements through three years of follow-up.

Liver stiffness metrics serve as a common, non-invasive indicator used by clinicians to forecast long-term structural hepatic outcomes.

Livdelzi is a first-in-class selective peroxisome proliferator-activated receptor delta (PPAR-delta) agonist.

The therapeutic agent holds active regulatory approvals for use in combination with ursodeoxycholic acid (UDCA) in adults with inadequate responses to standard care, or as a monotherapy for patients intolerant to UDCA, across major international jurisdictions including the United States, the United Kingdom, Canada, and the European Economic Area.