SNY Down Despite Eczema Candidate Meeting Goal in Phase III Study

Core Insights - Sanofi announced positive results from the phase III COAST 1 study for amlitelimab, an anti-OX40L monoclonal antibody, aimed at treating moderate-to-severe atopic dermatitis in patients aged 12 and above [1][7] - The study achieved all primary and key secondary endpoints, demonstrating significant skin clearance and improvement in disease severity compared to placebo [2][7] Study Results - Amlitelimab, administered every four weeks or every 12 weeks, showed statistically significant and clinically meaningful efficacy in skin clearance and disease severity at week 24 [2] - The treatment was generally safe and well-tolerated, with no new safety concerns reported [2] Market Reaction - Despite the positive data, Sanofi's shares fell by 8.8% in pre-market trading on September 4, as the results did not meet investor expectations [3] - Analysts expressed concerns that amlitelimab may be less effective than Sanofi's existing drug Dupixent, which is a leading treatment for various inflammatory diseases [3] Dupixent Performance - In the first half of 2025, Dupixent generated sales of €7.31 billion, marking a 20.7% year-over-year increase [4] - Dupixent holds the top new-to-brand prescription market share across all its approved indications in the U.S., with ongoing efforts to expand its label [4] Stock Performance - Year-to-date, Sanofi's shares have increased by 3.5%, contrasting with a 0.1% decline in the industry [5] Future Developments - Amlitelimab is part of the OCEANA clinical development program, which includes four other phase III studies, with data expected through 2026 [9][10] - Positive results from these studies could support global regulatory filings for amlitelimab for atopic dermatitis [9] Additional Indications - Besides atopic dermatitis, Sanofi is also exploring amlitelimab for celiac disease, alopecia areata, asthma, and systemic sclerosis in mid-stage studies [10]