Will amlitelimab be the first and best-in-class novel investigational anti-OX40-ligand monoclonal antibody?

Sanofi’s amlitelimab showed statistically significant improvements in signs and symptoms of moderate-to-severe atopic dermatitis in adults, according to topline Phase 2b data.

Amlitelimab is a fully human non-depleting monoclonal antibody that binds to OX40-Ligand, a key immune regulator, and has the potential to be a first-in-class treatment for a range of immune-mediated diseases and inflammatory disorders, including moderate-to-severe atopic dermatitis and asthma. By targeting OX40-Ligand, amlitelimab aims to restore immune homeostasis between pro-inflammatory and regulatory T cells. Amlitelimab is currently under clinical investigation, and its safety and efficacy have not been evaluated by any regulatory authority.

The study met its primary endpoint of percentage change in Eczema Area and Severity Index score from baseline at 16 weeks, with continued improvement seen through 24 weeks; improvements also seen in key secondary endpoints at 16 and 24 weeks. 

In this dose-ranging study, treatment with amlitelimab resulted in statistically significant improvements in average Eczema Area and Severity Index (EASI) score from baseline at 16 weeks compared to placebo for all four subcutaneous doses that were studied. There were also improvements in key secondary outcome measures and continued improvements were observed through week 24 in primary and key secondary outcomes. Biomarker results support an effect on both type 2 and non-type 2 pathways.

Amlitelimab was well-tolerated in the study across all dose arms, and no new safety concerns were identified.

The Phase 2b study (STREAM-AD) included adults with moderate-to-severe atopic dermatitis whose disease cannot be adequately controlled with topical medications or for whom topical medications are not a recommended treatment approach. The study enrolled 390 people in Australia, Bulgaria, Canada, Czechia, Germany, Hungary, Japan, Poland, Spain, Taiwan, the United Kingdom and the United States.