CymaBay Therapeutics Announces Publication of Results From the ENHANCE, Phase 3 Study of Seladelpar in Patients with Primary Biliary Cholangitis (PBC)

CymaBay Therapeutics, a biopharmaceutical company focused on developing and providing access to innovative therapies for patients with liver and other chronic diseases, today announced that results from the ENHANCE phase 3 global study evaluating seladelpar for primary biliary cholangitis (PBC) have been published.

This double-blind, placebo-controlled, global phase 3 study evaluated the efficacy and safety of seladelpar, a potent, selective, orally active PPARδ agonist, or delpar, after 3 months of treatment in patients with PBC. Patients with elevated alkaline phosphtase (≥ 1.67x upper-limit-of-normal) received treatment as an add-on to first line ursodeoxycholic acid (UDCA), or as monotherapy, if patients were intolerant to UDCA. All pre-specified endpoints were assessed after 3 months in patients receiving oral daily seladelpar 5 mg (n=56), 10 mg (n=55) or placebo (n=56). The primary endpoint was a composite of alkaline phosphatase and bilirubin² previously accepted by FDA for pivotal studies in PBC. The composite endpoint was achieved in 78.2% of patients on seladelpar 10 mg and 57.1% on seladelpar 5 mg versus 12.5% on placebo (both seladelpar doses with p<0.0001). A key secondary endpoint of having normal levels of alkaline phosphatase was met in 27.3% (p<0.0001) and 5.4% (p=0.08) in seladelpar 10 mg and 5 mg groups, respectively, versus none in the placebo group. The final key secondary endpoint assessed the patient-reported symptom of pruritus (itching) using a daily pruritus numerical rating scale (NRS; 0-10). Statistically significant improvement in pruritus (p<0.02) for patients with moderate-to severe itch (NRS ≥4) was demonstrated for seladelpar 10 mg versus placebo. Patients taking seladelpar also had significant improvements in markers of liver injury. There were no treatment related adverse endpoints in the study.

Lead author and investigator Professor Gideon Hirschfield, FRCP PhD, Lily and Terry Horner Chair in Autoimmune Liver Disease at the University of Toronto, commented, “Patients with PBC are in need of new therapies that are well tolerated and provide clinical benefits. Data from this study support continued development of seladelpar for patients with PBC. Seladelpar has the potential to offer anti-cholestatic, anti-inflammatory and anti-pruritic benefits for patients at a higher risk of disease progression and for those continuing to suffer from symptom burden.”

Seladelpar is currently being evaluated in RESPONSE, a global phase 3 registration study in patients with PBC, that is expected to read out in the third quarter of 2023. Seladelpar’s development program also includes ASSURE, a global phase 3 long-term study that allows continued treatment with seladelpar in study subjects completing a prior seladelpar study. It is expected that ASSURE will contribute safety and efficacy data on more than 300 patients treated with seladelpar.