Phase III Trials Show Povorcitinib Significantly Improves Hidradenitis Suppurativa Outcomes

Image Credit: Adobe Stock Images/Kristina Blokhin

Results from the Phase III STOP-HS1 and STOP-HS2 trials show that povorcitinib (Incyte), an oral JAK1 inhibitor, successfully met the primary endpoint in treating moderate to severe hidradenitis suppurativa (HS). The trials demonstrated that a significantly higher proportion of patients treated with povorcitinib achieved Hidradenitis Suppurativa Clinical Response (HiSCR) compared to placebo. Notably, patients who had previously received biologic treatments experienced even greater efficacy with povorcitinib.¹

"[HS] is a challenging and debilitating condition without a cure. Given the limitations of current HS treatments and its impact on patients’ daily lives, there is a critical need for new, well tolerated and effective therapies that provide a rapid reduction in the signs and symptoms of HS, in particular, pain," said Steven Stein, MD, chief medical officer, Incyte, in a press release. "The positive Phase III data highlights the potential of povorcitinib as an effective oral treatment option for people living with HS.”

Both the STOP-HS1 and STOP-HS2 trials were 12-week, double-blind studies with a placebo-controlled treatment period, followed by a 42-week extension, and a 30-day safety follow-up. Each trial included approximately 600 patients, all of whom had been diagnosed with HS for at least three months prior to study initiation.

The primary endpoint for both trials was proportion of patients achieving HiSCR50, which investigators defined as a minimum 50% drop from baseline in total abscess and inflammatory nodule (AN) count at week 12. Secondary endpoints included the percentage of patients achieving a 75% decrease in AN count without experiencing an increases in abscess or draining tunnel count; proportion of patients experiencing at least one flare-up through week 12; proportion of patients with a >3-point decrease in the Skin Pain Numeric Rating Scale (NRS) score among those with a baseline score of ≥3; and percentage of patients achieving at least a 30% decrease with a minimum 1-unit decrease from baseline in the Skin Pain NRS at week 12.

In the STOP-HS1 trial, 34.2% of patients administered povorcitinib 45 mg achieved HiSCR50 compared to 21.9% in the placebo group. In the povorcitinib 75 mg group, 37.8% achieved HiSCR50 compared to 21.9% in the placebo group.

In the STOP-HS2 trial, 45.0% of patients administered 45 mg povorcitinib achieved HiSCR50, compared to 19.5% in the placebo group. For the 75 mg povorcitinib dose, 40.0% of patients achieved HiSCR50 compared to 19.5% in the placebo group. For the secondary endpoints, povorcitinib demonstrated significant improvements in HiSCR75, skin pain reduction, and flare frequency at week 12.

The safety profile of povorcitinib was consistent with previous data, with no new safety concerns. Both doses were well tolerated by patients, and there were no significant changes in adverse event rates compared to placebo.¹

According to a study published in JAMA Dermatology, the overall prevalence of HS is estimated to be 0.5% globally.² According to the Cleveland Clinic, women are more likely to get HS during their lifetime.³ Medline Plus states that it is also more common in Black people, smokers, people with overweight or obesity, and people with a family history of HS.⁴ According to the HS Foundation, approximately 30% of all people with HS have a family history of it. While HS most commonly starts during puberty, it can develop in patients between 40 and 50 years of age.⁵

References

1. Incyte Announces Positive Topline Results From Two Phase 3 Clinical Trials of Povorcitinib in Patients With Hidradenitis Suppurativa. Incyte. March 17, 2025. Accessed March 19, 2025. https://investor.incyte.com/news-releases/news-release-details/incyte-announces-positive-topline-results-two-phase-3-clinical

2. Prevalence of Hidradenitis Suppurativa A Systematic Review and Meta-regression Analysis. JAMA Network. Accessed March 19, 2025. https://jamanetwork.com/journals/jamadermatology/fullarticle/2780049

3. Hidradenitis Suppurativa. Cleveland Clinic. Accessed March 19, 2025. https://my.clevelandclinic.org/health/diseases/17716-hidradenitis-suppurativa

4. Hidradenitis Suppurativa. Medline Plus. Accessed March 19, 2025. https://medlineplus.gov/hidradenitissuppurativa.html

5. What is HS (Hidradenitis Suppurativa)? HS Foundation. Accessed March 19, 2025. https://www.hs-foundation.org/what-is-hs