Phase 2 Readouts: Lunsekimig Met Endpoints in Asthma and CRSwNP

Key points:

• Lunsekimig met primary and key secondary endpoints in Phase 2 studies in asthma and CRSwNP
• The therapy targets both TSLP and IL-13 via a bispecific Nanobody® design
• An exploratory Phase 2 study in atopic dermatitis did not meet its primary endpoint but showed improvements in secondary measures
• Treatment was generally well tolerated across studies
• Further clinical development is ongoing

Sanofi reported positive results from two Phase 2 studies of its investigational bispecific therapy lunsekimig in respiratory diseases, alongside mixed findings in a third study, according to a company announcement released April 7, 2026.

Lunsekimig is an engineered Nanobody® composed of linked antibody fragments designed to simultaneously inhibit thymic stromal lymphopoietin (TSLP) and interleukin-13 (IL-13), two inflammatory drivers implicated in asthma and related conditions.

In the Phase 2b AIRCULES study in moderate-to-severe asthma, lunsekimig met its primary and key secondary endpoints. The treatment demonstrated a statistically significant reduction in exacerbations and improvements in lung function, as measured by pre-bronchodilator forced expiratory volume in one second (FEV₁), compared with placebo.

Similarly, in the Phase 2a DUET study in chronic rhinosinusitis with nasal polyps (CRSwNP), the therapy met its primary endpoint of change in nasal polyp score from baseline. It also met key secondary endpoints, including improvements in nasal congestion and imaging-based measures of sinus disease at Week 24.

In contrast, results from the exploratory Phase 2b VELVET study in moderate-to-severe atopic dermatitis were mixed. The trial did not meet its primary endpoint of percent change from baseline in eczema area and severity index (EASI) score. However, improvements were observed in secondary endpoints assessing skin clearance, including the proportion of patients achieving EASI-75 and favorable investigator global assessment scores.

Across all three studies, lunsekimig was reported to be generally well tolerated, with adverse event rates and discontinuations comparable to placebo. Common treatment-emergent adverse events included upper respiratory tract infections, nasopharyngitis, headache, and injection-site reactions, depending on the study population.

Sanofi stated that detailed results from the AIRCULES, DUET, and VELVET trials will be presented at upcoming medical meetings. The company also noted that lunsekimig remains in clinical development, with additional ongoing studies, including Phase 2 and Phase 3 trials, and that its safety and efficacy have not yet been established by regulatory authorities.

Overall, the findings support continued development of lunsekimig in respiratory indications, with positive mid-stage results in asthma and CRSwNP and variable outcomes observed in atopic dermatitis.