Sanofi’s bispecific nanobody lunsekimig won two respiratory Phase 2 trials and failed one eczema trial on the same day, leaving the company without a clear successor to Dupixent as that drug’s patent cliff approaches.
The drug cleared the Aircules phase 2b study in moderate-to-severe asthma, hitting a statistically significant reduction in exacerbations at 48 weeks. It also hit the primary endpoint in the Duet phase 2a study for chronic rhinosinusitis with nasal polyps. Two wins in one morning.
But the Velvet phase 2b study for atopic dermatitis missed its primary endpoint. Dupixent generated roughly $13B in 2024 sales and lunsekimig was supposed to be the heir apparent. It showed secondary endpoint improvements like skin clearance, but that won’t satisfy analysts watching the patent clock.
Sanofi ousted its CEO in February after a year of clinical setbacks. Two Phase 2 wins in one morning break that losing run. They’re not the Dupixent succession answer it needed more.
Lunsekimig targets both TSLP and IL-13, competing in a space that now includes Pfizer’s tilrekimig. The drug is already in two Phase 3 studies for COPD.
The eczema program isn’t dead. Full data goes to upcoming medical congresses — no dates announced.
Sarah Chen