HS-OBTAIN: Brivekimig Achieves Positive Results in Hidradenitis Suppurativa

Treatment of hidradenitis suppurativa (HS) with brivekimig has resulted in clinically meaningful HS improvements among biologic-naïve patients compared to placebo at Week 16, according to recent findings.1

These data, presented at the European Academy of Dermatology and Venereology (EADV) 2025 Congress in Paris, resulted from the HS-OBTAIN phase 2a study (NCT05849922) assessing brivekimig in patients with HS.1 HS is a chronic and debilitating inflammatory skin condition that commonly features painful cutaneous nodules, abscesses, and draining tunnels.

“Despite the debilitating impact of HS, treatment options are unfortunately limited,” Alexa B. Kimball, MD, MPH, professor of dermatology at Harvard Medical School, said in a statement.1 “The phase 2a results presented at EADV indicate targeting TNF and OX40L pathways together with brivekimig may offer a promising strategy to reduce underlying inflammation, leading to improvement in HS symptoms.”

Brivekimig was designed as a dual-target Nanobody block both tumor necrosis factor (TNF) and OX40-ligand. These are both known to be important immune mediators. The medication is currently under investigation for its application in several immune-mediated and inflammatory conditions.

During the HS-OBTAIN trial, a phase 2a randomized, double-blind, placebo-controlled proof-of-concept study design was used. The research team evaluated the safety and efficacy of brivekimig in adults patients with moderate-to-severe HS. Those taking part as subjects were assigned in a 2:1 ratio to receive either subcutaneous brivekimig 150 mg or placebo every 2 weeks for a total of 16 weeks.

This was followed by a 12-week open-label extension and an additional 8-week safety follow-up. The investigative team's main endpoint was the proportion of biologic-naïve individuals attaining a Hidradenitis Suppurativa Clinical Response (HiSCR50) at the 16-week mark, evaluated through the use of a Bayesian logistic regression model adjusted for Hurley stage.

In their assessment of secondary endpoints, the team included reports of HiSCR75, HiSCR90, and shifts in draining tunnel count. These secondary endpoints were each assessed at Week 16 with adjusted estimates and nominal p-values.

Outcomes related to efficacy at the 16-week mark included:

• HiSCR50 (≥50% reduction in abscesses and inflammatory nodules without worsening of abscess or fistula counts): attained by 67% of individuals involved as participants treated with brivekimig (n=48) compared with 37% in the placebo arm (n=23). The Bayesian primary analysis indicated an estimated difference of 29% (90% credible interval [CrI]: 10%–47%), with a 99.28% probability of superiority.
• HiSCR75: 54% of brivekimig-treated subjects attained this outcome compared with 22% of placebo-treated individuals (estimated difference 29%; 90% CI: 11%–48%; P = .0171).
• HiSCR90: 31% of those in the brivekimig cohort attained this threshold compared with 9% in the placebo cohort (estimated difference 20%; 90% CI: 5%–34%; P = .0576).
• Draining tunnel count: mean percent change from baseline was –56.0% for those on brivekimig versus +10.9% given a placebo, representing an estimated difference of –67.0% (90% CI: –105.2% to –28.8%; P = .005).

In assessing safety findings, HS-OBTAIN investigators found the most common treatment-emergent adverse events (taking place in more than 10% of subjects and at higher frequency with brivekimig than placebo) were nasopharyngitis and headache.

Brivekimig remains an investigational agent for HS and has not yet undergone regulatory review or approval.

References

1. Press Release: EADV: Sanofi’s brivekimig achieved positive results in hidradenitis suppurativa in phase 2a study. Sanofi. September 17, 2025. https://www.sanofi.com/en/media-room/press-releases/2025/2025-09-17-05-00-00-3151353. Accessed September 18, 2025.