Regeneron's $3.124 Billion Trading Volume Surges 586.67% Despite Stock Plunge and COPD Treatment Failure

On May 30, 2025, Regeneron's trading volume reached $3.124 billion, marking a significant 586.67% increase from the previous day, placing it 20th in the day's stock market rankings. Regeneron's stock price fell by 19.01%.

Regeneron Pharmaceuticals' stock plummeted after its COPD treatment, developed in partnership with Sanofi, failed unexpectedly in a Phase 3 study. This setback is likely to hinder the companies' ability to seek regulatory approval for the treatment. The drug, itepekimab, was tested in two separate studies involving patients with chronic obstructive pulmonary disease (COPD).

In one study, patients experienced a 21% to 27% reduction in exacerbations after a year, meeting the threshold for clinical significance. However, the second study showed almost no benefit by the 52nd week, indicating inherent challenges in COPD studies, such as the disease's severity and variability. Analysts suggest that another Phase 3 study may be necessary to gain FDA approval, but this could be futile and add years to the development program. The divergent results and potential waning effects of the drug may further reduce the likelihood of success in future studies and commercial enthusiasm if the drug eventually reaches the market.