Phase 2 trial results have come out strong for Sanofi’s lunsekimig, an investigational drug therapy designed to treat chronic respiratory diseases, including high‑risk asthma. Sanofi announced the encouraging results of “A Randomized, Phase 2, Double-Blind, Placebo-Controlled, Parallel-Group, 2-Arm Study to Investigate the Efficacy, Safety and Tolerability of Subcutaneous Lunsekimig (SAR443765) in Adult Participants With High-Risk Asthma Who Are Not Currently Eligible,” in a press release from its recent phase 2 clinical studies.
According to Sanofi, multiple phase 2 studies demonstrated that lunsekimig met key efficacy endpoints and was generally well tolerated, reinforcing its potential as a novel treatment option for patients with limited therapeutic alternatives.
“These data are promising and support our belief that the dual-targeting mechanism of lunsekimig may offer a novel treatment option for patients living with respiratory diseases, including asthma,” said Sanofi’s Houman Ashrafian in the press release. Ashrafian is executive vice president and head of research and development. “Importantly, these findings underscore lunsekimig’s potential to address multiple critical aspects of respiratory disease management through its unique mechanism.”
Lunsekimig is a bispecific Nanobody® (VHH) composed of five linked antibody fragments that simultaneously block thymic stromal lymphopoietin (TSLP) and interleukin‑13 (IL‑13) — two inflammatory drivers implicated in asthma and related diseases. By targeting both pathways, Sanofi researchers said the therapy aims to address multiple aspects of disease inflammation and tissue damage.
In the AIRLYMPUS program, a randomized, double‑blind, placebo‑controlled phase 2 study, lunsekimig was evaluated as an add‑on subcutaneous therapy in adults aged 18 to 80 with high‑risk asthma who are not eligible for existing biologic treatments. Participants were treated for up to 52 weeks, with the overall study lasting approximately 60 to 64 weeks, depending on follow‑on participation.
Sanofi reported that the AIRCULES phase 2b study met its primary and key secondary endpoints, demonstrating a statistically significant and clinically meaningful reduction in asthma exacerbations. Researchers noted improvements in lung function, as measured by pre‑bronchodilator forced expiratory volume in one second (FEV1), regardless of biomarker status.
Beyond asthma, researchers reported that lunsekimig also showed positive results in chronic rhinosinusitis with nasal polyps. The DUET phase 2a proof‑of‑concept study met its primary endpoint, showing improvement in nasal polyp scores as well as key secondary endpoints related to nasal congestion and CT imaging scores at week 24 compared to placebo.
An exploratory VELVET phase 2b study in moderate‑to‑severe atopic dermatitis did not meet its primary endpoint. However, patients experienced improvements in several secondary measures of skin clearance, suggesting potential activity outside respiratory indications.
Across all studies, lunsekimig was generally well tolerated. The most reported treatment‑emergent adverse events included mild infections such as nasopharyngitis, upper respiratory tract infections, headaches and injection‑site reactions. Rates of serious adverse events and treatment discontinuation were similar between lunsekimig and placebo groups.
Sanofi said that detailed findings from the AIRCULES, DUET and VELVET studies will be presented at upcoming medical congresses, as the company continues to evaluate lunsekimig’s future development pathway.
