Povorcitinib Efficacy in 2 Pivotal Phase 3 Trials Will Support Global Regulatory Submission for Hidradenitis Suppurativa
Both trials met their primary endpoints, demonstrating a statistically significant improvement in HiSCR50 compared to placebo, with a favorable safety profile, according to Incyte.
Positive topline results from the pivotal phase 3 STOP-HS1 and STOP-HS2 clinical trials evaluating povorcitinib in adult patients with moderate to severe hidradenitis suppurativa (HS), "will support planned regulatory submission" for the oral small-molecule JAK1 inhibitor worldwide, according to an announcement today from developer Incyte.1
Both trials met their primary endpoints, demonstrating a statistically significant improvement in Hidradenitis Suppurativa Clinical Response (HiSCR50) at both tested doses (45 mg and 75 mg) compared to placebo, with a favorable safety profile.1
In STOP-HS1, the proportion of study participant achieving HiSCR50 at week 12 was 40.2% for the 45 mg dose and 40.6% for the 75 mg dose, compared to 29.7% in the placebo group (P =.024 and P =.022, respectively). STOP-HS2 yielded similar results, with 42.3% of participants in both dose groups achieving HiSCR50, compared to 28.6% in the placebo group (P =.004 and P =.003, respectively). In a subgroup of participants with prior exposure to biologic therapies, povorcitinib exhibited enhanced efficacy, particularly in STOP-HS2, where the 45 mg and 75 mg doses achieved HiSCR50 rates of 45.0% and 40.0%, respectively, versus 19.5% in the placebo group (P =.001 and P =.005), according to the Incyte press statement.1
HiSCR: at least a 50% reduction in total abscess and inflammatory nodule count, with no increase in abscess count, and no increase in draining fistula count relative to baseline.
Beyond the primary endpoint, povorcitinib demonstrated deep clinical responses, with investigators reporting a greater proportion of active drug-treated participants reaching HiSCR75, flare reductions, and reductions in skin pain of 3 points or more as assessed via the Numeric Rating Scale (NRS). Incyte also documented rapid onset of response, including early pain relief. The safety profile of povorcitinib remained consistent with prior data, with no new safety signals identified.1
HS is a painful chronic inflammatory dermatologic condition believed to be caused by overactive behavior of the JAK/STAT intracellular signaling pathway.2 the characteristic nodules and abscesses can cause irreversible tissue damage and lifetime scarring.3
"Hidradenitis suppurativa is a debilitating condition that significantly affects patients' quality of life. Given the limitations of current therapies, there is an urgent need for well-tolerated treatments that provide rapid symptom relief," Steven Stein, MD, Incyte chief medical officer, said in the release. "The positive [p]hase 3 results support povorcitinib’s potential as a novel oral treatment option for patients with HS."1
Further data from the STOP-HS program will be presented at upcoming scientific meetings, the company said.
Both STOP-HS trials enrolled approximately 600 participants aged 18 years or older with a confirmed diagnosis of HS a minimum of 3 months before screening. Participants also met additional inclusion criteria: total AN count of 5 or more, lesions in at least 2 distinct anatomical areas, and a documented history of inadequate response to at least a 3-month course of at least one conventional systemic therapy (oral antibiotic or biologic drug) for HS, or be otherwise unable to use conventional treatments.1
Each study assessed povorcitinib efficacy and safety over a 12-week double-blind, placebo-controlled period, followed by a 42-week extension period and a 30-day safety follow-up, according to the release. Key secondary endpoints included HiSCR75 rates, flare frequency, and skin pain reduction. Adverse event monitoring confirmed tolerability consistent with previous studies.1
Additional clinical trial details are available at clinicaltrials.gov (NCT05620823, NCT05620836).
