Impact of setanaxib on quality of life outcomes in primary biliary cholangitis in a phase 2 randomized controlled trial

Background: There is a real unmet need for primary biliary cholangitis (PBC) treatments that can improve quality of life impacting symptoms. In this post hoc analysis, we evaluated potential effects of the NADP oxidase 1/4 inhibitor, setanaxib, on patient-reported quality of life from a phase 2 trial in PBC. Patients and Methods: The underpinning double-blind, randomized, placebo-controlled trial (NCT03226067) recruited 111 patients with PBC and inadequate response/intolerance to ursodeoxycholic acid. Patients self-administered oral placebo (n = 37), setanaxib 400 mg once daily (OD; n = 38), or setanaxib 400 mg twice daily (BID; n = 36), in addition to ursodeoxycholic acid for 24 weeks. Quality of life outcomes were assessed using the validated PBC-40 questionnaire. Patients were stratified post hoc by baseline fatigue severity. Results: At week 24, patients treated with setanaxib 400 mg BID reported greater mean (SE) absolute reductions from baseline in PBC-40 fatigue domain score [–3.6 (1.3)] versus those receiving setanaxib 400 mg OD [–0.8 (1.0)]) or placebo [0.6 (0.9)]. Similar observations were made across all PBC-40 domains except itch. In the setanaxib 400 mg BID arm, patients with moderate-to-severe fatigue at baseline had a greater reduction in mean fatigue score at week 24 [–5.8 (2.1)] versus those with mild fatigue [–0.6 (0.9)]; results were similar across all domains. Reduced fatigue was correlated with emotional, social, symptom, and cognitive improvements. Conclusions: These results support further investigation of setanaxib as a treatment for patients with PBC, particularly for those with clinically significant fatigue.