A Phase 2, Randomized, Double-Blind, Placebo-Controlled Study Evaluating the Efficacy and Safety of Ritlecitinib in Adults with Moderate to Severe Hidradenitis Suppurativa

The primary objective of this study is to evaluate the efficacy of ritlecitinib compared to a placebo in adults with hidradenitis suppurativa, as measured by the Hidradenitis Suppurativa Clinical Response (HiSCR50). 5: Efficacy.

Secondary objectives include the assessment of:

• Efficacy via HiSCR75, HiSCR90, and total abscess count.
• Impact on disease flare.
• Reduction of pain and other clinical symptoms.
• Safety and tolerability profile. 4: Safety.
• Changes in quality of life related to the condition.
• Disease severity using the International Hidradenitis Suppurativa Severity Score System (IHS4).
• Hidradenitis Suppurativa Investigator Global Assessment (HS-IGA).

The study involves 49 participants diagnosed with hidradenitis suppurativa. The study population includes both male and female individuals within a specific age range. Eligible subjects must have a documented clinical diagnosis of the disease for a minimum of 6 months and present with moderate to severe disease, classified as Hurley Stage II or III. Selection requires the presence of at least 5 inflammatory lesions across 2 distinct anatomical areas at baseline. Additionally, participants must have demonstrated an inadequate response to a minimum 4-week course of systemic therapy or possess a documented medical reason for the avoidance of such treatment.

This Phase 2, multicenter, randomized, double-blind, placebo-controlled study is designed to evaluate the safety and efficacy of ritlecitinib tosilate in adults with moderate to severe hidradenitis suppurativa. The primary objective is to assess the Hidradenitis Suppurativa Clinical Response (HiSCR50) at Week 16. Eligible participants include adults aged 18 to 75 years with a documented clinical diagnosis of the disease for at least 6 months, meeting Hurley Stage II or III criteria, and demonstrating an inadequate response to systemic therapy. The study involves an initial screening visit to confirm eligibility, followed by a 16-week treatment period. During this period, participants receive either the active capsule or a placebo administered via the oral route. Clinical assessments and follow-up evaluations occur at Weeks 1, 2, 4, 6, 8, 12, and 16 to monitor efficacy and safety, including the incidence of treatment-emergent adverse events. Total participant involvement is expected to span the 16-week treatment duration.

The experimental treatment consists of ritlecitinib tosilate administered in capsule form. This medication is intended for oral administration.

The control group receives a placebo for pf-06651600-15, which is used as a comparator in this study for hidradenitis suppurativa.

The efficacy of ritlecitinib in adults with moderate to severe hidradenitis suppurativa is primarily assessed through the HiSCR50 response at Week 16. Secondary endpoints include HiSCR75 and HiSCR90 responses at Weeks 1, 2, 4, 6, 8, 12, and 16. Clinical response is further evaluated based on the total abscess and nodule (AN) count at Week 16, including specific thresholds of 0 or 1, and 0, 1, or 2. The percent change from baseline (CFB) in the total AN count is measured at Weeks 1, 2, 4, 6, 8, 12, and 16.

Additional assessments involve the Hidradenitis Suppurativa Investigator Global Assessment (HS-IGA), measuring absolute scores and CFB, as well as the achievement of an HS-IGA score of 0 or 1 at multiple timepoints from Week 1 through Week 16. The occurrence of an HS flare, defined by a minimum 25% increase in total AN count with at least 2 additional lesions relative to baseline, is monitored at Weeks 4, 8, 12, and 16. Efficacy is also evaluated using the Hidradenitis Suppurativa Symptom Daily Diary (HSSDD) to determine CFB. Pain is assessed via the Numeric Rating Scale (NRS), specifically focusing on NRS30, NRS50, and NRS70 responses, as well as CFB in skin pain at various intervals for participants with a baseline NRS ≥3.

Quality of life and disease severity are measured using the Hidradenitis Suppurativa Quality of Life (HiSQOL) instrument and the IHS4 scale, tracking absolute scores and CFB at Weeks 1, 2, 4, 6, 8, 12, and 16.