Sanofi Announces Positive Phase 2a Results for Brivekimig in HS

Sanofi has reported positive results from the HS-OBTAIN phase 2a study (NCT05849922) of brivekimig, a novel dual-target Nanobody molecule, in biologic-naive patients with moderate to severe hidradenitis suppurativa (HS).¹ The data, presented at the 2025 European Academy of Dermatology and Venereology (EADV) Congress in Paris, France, demonstrated clinically meaningful improvements in both primary and key secondary end points at week 16 compared with placebo, along with a favorable safety profile.

“Despite the debilitating impact of HS, treatment options are unfortunately limited,” Alexa Kimball, MD, MPH, professor of dermatology at Harvard Medical School, said in the press release. “The phase 2a results presented at EADV indicate targeting TNF [tumor necrosis factor] and OX40L [OX40 ligand] pathways together with brivekimig may offer a promising strategy to reduce underlying inflammation, leading to improvement in HS symptoms.”¹

Methods and Material

HS-OBTAIN is a randomized, double-blind, placebo-controlled, proof-of-concept phase 2a trial designed to evaluate the efficacy and safety of brivekimig 150 mg administered subcutaneously every 2 weeks over a 16-week treatment period, followed by a 12-week open-label phase and an 8-week safety follow-up. The study enrolled 71 biologic-naive adults with moderate to severe HS. Participants were randomly assigned 2:1 to receive either brivekimig (n = 48) or placebo (n = 23). The primary efficacy end point at 16 weeks was the proportion of patients achieving HS Clinical Response (HiSCR50), which was defined as a greater than or equal to 50% reduction in abscess and inflammatory nodule count with no increase in abscess or draining fistula count. The proportions of patients reaching HiSCR75 and HiSCR90 were considered secondary end points.

Efficacy and Safety Results

When compared with placebo, brivekimig demonstrated statistically and clinically significant improvements across primary and secondary end points, including the following:

• HiSCR50 was achieved in 67% of brivekimig-treated patients vs 37% with placebo.
• HiSCR75 was achieved in 54% of brivekimig-treated patients vs 22% with placebo.
• HiSCR90 was achieved in 31% of brivekimig-treated patients vs 9% with placebo.
• The mean percent change in draining tunnel count was –56.0% for brivekimig vs +10.9% for placebo.

Brivekimig was generally well tolerated, with no serious adverse events reported. The most common adverse effects were nasopharyngitis and headache. These occurred in more than 10% of patients and were more frequent in the brivekimig group than in the placebo arm.

Future Exploration of Brivekimig

Brivekimig for the treatment of HS, which affects approximately 196,000 adult patients in the European Union, is investigational and has not been evaluated by any regulatory authority. The dual-target Nanobody molecule, which inhibits the TNF and OX40L immune regulators, is being investigated for other immune-mediated diseases and inflammatory disorders. This reaffirms Sanofi’s commitment to addressing underlying inflammation across complex, heterogeneous chronic skin diseases, according to the company.

“The positive early-stage results for brivekimig in HS presented at EADV exemplify our deep understanding of pathway biology and commitment to exploring novel platforms and technologies with the goal of delivering new treatment options that can address the complex, heterogeneous nature of chronic inflammatory skin diseases,” said Alyssa Johnsen, MD, PhD, Global Therapeutic Area Head for Immunology and Oncology Development at Sanofi. “We are encouraged by these results and look forward to continuing to explore brivekimig and the impact of dual TNF and OX40 ligand inhibition on the inflammation driving the burdensome symptoms of HS.”¹

Reference

1. EADV: Sanofi’s brivekimig achieved positive results in hidradenitis suppurativa in phase 2a study. News release. Globe Newswire. September 17, 2025. Accessed September 17, 2025. https://www.globenewswire.com/news-release/2025/09/17/3151353/0/en/Press-Release-EADV-Sanofi-s-brivekimig-achieved-positive-results-in-hidradenitis-suppurativa-in-phase-2a-study.html