Phase 3 Extension Study of Long-Term Safety and Efficacy of Remibrutinib in Adults With Moderate to Severe Hidradenitis Suppurativa

The primary objective is to evaluate the long-term safety of remibrutinib in adult participants with moderate to severe hidradenitis suppurativa, which is clinically relevant for characterizing tolerability during extended treatment. The secondary objectives are to evaluate long-term observed efficacy during year 1 and after year 1 of the extension study, including the proportion of participants achieving AN50/75/90 response, the mean percentage change from baseline in IHS4, the proportion of participants achieving HiSCR 50/75/90 response, and the proportion of participants with clinical response in HS-related skin pain (NRS30, worst case).

The trial population comprised 564 participants with hidradenitis suppurativa, including both female and male participants and patients considered vulnerable. The population included adult participants with moderate to severe disease. Participants were selected from those who had completed the full 68-week treatment period in the core studies CLOU064J12301 or CLOU064J12302 and who did not meet any treatment discontinuation criteria at Week 68. Relevant eligibility requirements included signed informed consent, the ability to communicate effectively with the investigator, and willingness and ability to comply with study requirements.

This is a double-blind, double-dummy, parallel-group, multicenter Phase 3 extension study evaluating two doses of remibrutinib in adult participants with moderate to severe hidradenitis suppurativa. The main objective is to assess the safety of long-term treatment. Participants are required to complete the full 68-week treatment period in the core studies and must not meet any treatment discontinuation criteria at Week 68. Study participation begins with an inclusion screening visit, where eligibility is confirmed and informed consent is obtained before any assessment is performed. This is followed by study treatment and scheduled follow-up visits according to the protocol, with an end-of-study visit at completion of the study period. The overall planned study duration extends from 30 September 2026 to 25 October 2032. Early termination from the study may occur if treatment discontinuation criteria are met.

The investigational treatment consisted of remibrutinib, administered as an oral film-coated tablet. Two doses were evaluated in adult participants with moderate to severe hidradenitis suppurativa. The study used a double-blind, double-dummy, parallel-group design, and treatment was given long term. The frequency of administration was not specified in the source data.

The non-experimental treatment was a matching placebo to remibrutinib film-coated tablet. Placebo and active treatment were used in a double-dummy manner to maintain blinding between study groups. Specific dose strength, route, and administration schedule for the placebo were not provided in the source data.

Compliance monitoring procedures were not described in the source data.

Efficacy will be assessed in adult participants with moderate to severe hidradenitis suppurativa using the achievement of AN50, AN75, and AN90, the percentage change from baseline in IHS4, the achievement of HiSCR50, HiSCR75, and HiSCR90, and the achievement of NRS30 among participants with baseline NRS ≥ 3 in the main studies.