ABSTRACT
Primary biliary cholangitis (PBC) is typically associated with elevated serum bile acid levels and pruritus, but pruritus is often refractory to treatment with existing therapies. This phase 2 study assessed the efficacy and safety of maralixibat, a selective, ileal, apical, sodium-dependent, bile acid transporter inhibitor, in adults with PBC and pruritus. Adults with PBC and pruritus who had received ursodeoxycholic acid (UDCA) for ≥6 months or were intolerant to UDCA were randomized 2:1 to maralixibat (10 or 20 mg/day) or placebo for 13 weeks in combination with UDCA (when tolerated). The primary outcome was change in Adult Itch Reported Outcome (ItchRO™) average weekly sum score (0, no itching; 70, maximum itching) from baseline to week 13/early termination (ET). The study enrolled 66 patients (maralixibat [both doses combined], n = 42; placebo, n = 24). Mean ItchRO™ weekly sum scores decreased from baseline to week 13/ET with maralixibat (-26.5; 95% confidence interval [CI], -31.8, -21.2) and placebo (-23.4; 95% CI, -30.3, -16.4). The difference between groups was not significant (P = 0.48). In the maralixibat and placebo groups, adverse events (AEs) were reported in 97.6% and 70.8% of patients, respectively. Gastrointestinal disorders were the most frequently reported AEs (maralixibat, 78.6%; placebo, 50.0%). Conclusion: Reductions in pruritus did not differ significantly between maralixibat and placebo. However, a large placebo effect may have confounded assessment of pruritus. Lessons learned from this rigorously designed and executed trial are indispensable for understanding how to approach trials assessing pruritus as the primary endpoint and the therapeutic window of bile acid uptake inhibition as a therapeutic strategy in PBC.
ABSTRACT
OBJECTIVES: The aim was to develop a clinical outcome assessment (COA) for itching in children with cholestatic pruritus. METHODS: This prospective study aimed to enroll patients aged 4-30 years with Alagille syndrome (ALGS) or progressive familial intrahepatic cholestasis type 1 and caregivers of patients aged 5 months to 14 years. Eligible patients experienced itching during ≥3 of the 7 days before enrollment and had not undergone liver transplant or surgical interruption of the enterohepatic circulation. Open-ended qualitative interviews confirmed that itching was a primary concern for patients and caregivers. Diaries were modified and then evaluated by participants during cognitive debriefing. Interview results were reviewed by clinical, COA and statistical experts. Diary questions were revised following an interim analysis before finalizing the Itch Reported Outcome (ItchRO). RESULTS: Thirty-six interviews were analyzed, representing 25 families of patients with ALGS. Itching was reported spontaneously (without prompting by the interviewer) by ten of 12 patients with ALGS and 19 of 20 caregivers. Consequences of itching included skin damage (78%), mood changes (59%), and difficulties staying asleep (59%) or falling asleep (53%). Two versions of the ItchRO were developed: ItchRO(Patient) for self-completion by patients and ItchRO(Observer) for caregivers. The ItchRO diaries comprise a single scorable item to assess itch and are to be completed twice daily (morning and evening). CONCLUSIONS: Itching was the most bothersome ALGS symptom reported by study participants. We have developed the ItchRO(Patient) and ItchRO(Observer) to assess itching in children with ALGS and other cholestatic liver diseases. These diaries are being validated for use in clinical trials.
