French healthcare company Sanofi S.A. (Euronext Paris:SAN) (Nasdaq:SNY) announced on Wednesday that its investigational therapy brivekimig achieved positive results in the phase 2a HS-OBTAIN study for moderate-to-severe hidradenitis suppurativa (HS).

HS is a chronic and debilitating inflammatory skin disease characterised by painful cutaneous nodules, abscesses and draining tunnels.

The trial demonstrated clinically meaningful improvements in the primary endpoint, with brivekimig showing higher response rates than placebo at week 16 in biologic-naïve patients.

Study results showed a 67% HiSCR50 response rate for brivekimig compared with 37% for placebo, with a probability of superiority above 99%. Secondary endpoints reinforced efficacy, with HiSCR75 achieved in 54% of brivekimig patients versus 22% for placebo, and HiSCR90 achieved in 31% versus 9%, respectively. Brivekimig also reduced draining tunnel counts by 56%, compared with a 10.9% increase on placebo.

Brivekimig was well tolerated, with no serious adverse events reported. The most common side effects were nasopharyngitis and headache.

A dual-target Nanobody inhibiting TNF and OX40L, brivekimig is being investigated for HS and other immune-mediated diseases. Results from the trial were presented at the European Academy of Dermatology and Venereology (EADV) 2025 Congress in Paris.