Sanofi Plunges 9.76% on Disappointing Drug Trial Data

On September 4, 2025, Sanofi's stock experienced a significant drop of 9.76% in pre-market trading, reflecting a notable decline in investor confidence.

Sanofi's stock price took a hit following the release of disappointing late-stage trial data for its experimental inflammatory disease drug, amlitelimab. The data indicated that the drug did not meet the primary endpoint, leading to a sharp decline in investor sentiment. This setback is particularly concerning as Sanofi had high hopes for amlitelimab, which was seen as a potential breakthrough in treating inflammatory diseases.

The negative trial results have raised questions about the future of Sanofi's pipeline and its ability to deliver on its promises. Investors are now closely watching the company's next steps, including any potential adjustments to its research and development strategy. The market reaction underscores the high stakes involved in drug development and the significant impact that clinical trial outcomes can have on a company's stock price.