The stock of Sanofi SA (NASDAQ: SNY) experienced a decline following disappointing results in late-stage trials for amlitelimab, a potential replacement for the successful eczema drug Dupixent. The global COAST 1 phase 3 study showed that amlitelimab met primary and key secondary endpoints, showing significant skin clearance and disease severity reduction compared to placebo in patients 12 years and older with moderate-to-severe atopic dermatitis at Week 24. However, analysts at William Blair pointed out that amlitelimab, the second anti-OX40 ligand (OX40L) antibody, did not meet expectations. Comparisons have been drawn with Amgen Inc.'s (NASDAQ: AMGN) rocatinlimab, as both fell short of Dupixent's effectiveness which saw a 36% improvement in EASI-75. This has raised concerns about Sanofi's ability to maintain its dermatology franchise post-patent expiration. For further details, visit Benzinga.com.