Povorcitinib Delivers Deepening Responses Through 54 Weeks in Moderate-to-Severe HS, With Martina Porter, MD

An oral selective JAK1 inhibitor has demonstrated sustained and deepening clinical response through 54 weeks in moderate-to-severe hidradenitis suppurativa (HS), with up to 29% of patients achieving complete abscess and inflammatory nodule clearance — adding a mechanistically distinct option to a treatment landscape that has expanded rapidly but remained anchored to injectable biologics.

To discuss the findings, we spoke with Martina L. Porter, MD, of Harvard Medical School and Beth Israel Deaconess Medical Center in Boston, presenting author of the 54-week STOP-HS data at the 2026 American Academy of Dermatology (AAD) Annual Meeting held in Denver, Colorado, from March 27-31. STOP-HS1 (NCT05620823) and STOP-HS2 (NCT05620836) are identically designed global phase 3 trials enrolling 1,227 adults total (STOP-HS1, n = 608; STOP-HS2, n = 619) with moderate-to-severe HS, randomized 1:1:1 to povorcitinib 75 mg once daily, 45 mg once daily, or placebo for a 12-week placebo-controlled period, followed by a 42-week blinded extension through week 54. Patients were required to have AN count ≥5 in ≥2 anatomic areas, Hurley stage II or III, disease duration ≥3 months, and prior systemic therapy — with 37.2% having previously received a biologic. Mean disease duration was 10.3 years (SD 9.4), mean AN count 12.0 (SD 8.8), and 75.5% had at least 1 draining tunnel at baseline.

At the primary endpoint of HiSCR50 at week 12, both doses were statistically significant versus placebo in both studies — 40.2% (45 mg) and 40.6% (75 mg) versus 29.7% placebo in STOP-HS1 (P <.025), and 42.3% for both doses versus 28.6% placebo in STOP-HS2 (P <.01) — with continuous improvement through week 54. By observed-cases analysis at week 54, HiSCR50 reached 60.2%–61.9% (STOP-HS1) and 57.3%–67.5% (STOP-HS2) in patients on continuous povorcitinib, with placebo crossover patients achieving comparable rates after switching at week 12. High-threshold responses deepened comparably, with up to 29.0% of patients achieving HiSCR100 at week 54. Full clearance of all inflammatory lesions (ANdT = 0) was achieved in 16.1%–20.2% of patients across both studies. Clinically meaningful improvements were observed across patient-reported outcome measures at week 54: ≥3-point decreases in skin pain NRS in 40.5%–58.0% of eligible patients, ≥4-point improvements in FATIGUE (FACIT-F) in 40.5%–49.0%, ≥4-point decreases in DLQI in 59.4%–64.7%, and ≥21-point decreases in HiSQoL total score in 33.7%–40.2%.

Safety through week 54 was consistent with the class profile — the most common TEAEs were acne (16.4%–21.1%), nasopharyngitis (9.4%–13.6%), and upper respiratory tract infection (9.1%–12.2%). Serious TEAEs occurred in 3.7%–6.4% of patients across arms, with no malignancies excluding NMSC reported and MACE occurring in only 1 patient (0.3%) in STOP-HS2. Porter contextualized povorcitinib's JAK1 mechanism as genuinely complementary to existing options: while TNF-α and IL-17 inhibitors — including secukinumab, bimekizumab, and the phase 3-complete agents izokibep and imsidolimab — share overlapping proximity in the inflammatory signaling cascade, JAK-STAT pathway inhibition operates through a distinct mechanism that may benefit patients who have already failed biologic therapy, and Porter suggested it could potentially be considered first line pending the FDA approval pathway.

“For some patients who have already taken biologics and had very minimal response, this could be very promising for them especially. But I've also seen in clinical practice that it has a variety effects of on different types of HS patients, and so I also think it could be considered first line in the future as well, depending on how It's [potentially] approved through the FDA,” Porter said.

Relevant disclosures for Porter include Abbvie, Bristol Myers Squibb, Janssen, Eli Lilly, Novartis, Pfizer, UCB, Trifecta Clinical, Incyte, and Anaptys Bio.

Reference

Porter ML, Martorell A, Sayed CJ, et al. Povorcitinib in patients with moderate to severe hidradenitis suppurativa: 54-week efficacy and safety results from the STOP-HS1 & STOP-HS2 phase 3 studies. Presented at: American Academy of Dermatology Annual Meeting; March 27–31, 2026; Denver, CO. Presentation 80034.