Why Regeneron Shares Lost Nearly 20%

Jun 2, 2025 - 14:00
Why Regeneron Shares Lost Nearly 20%

In the last year, Regeneron (REGN) performed poorly. REGN stock entered a prolonged downtrend, despite no major news that would explain the decline.

Last Friday, May 30, Regeneron and its drug development partner Sanofi (SNY) reported clinical phase 3 trials for a drug treating COPD. The companies reported disappointing data for a second study treating patients with Itepekimab. The stock fell by nearly 20%, suggesting an overreaction. Shareholders depended on Regeneron to enrich its drug pipeline. It needs new products to offset an eventual slowdown in sales of its blockbuster, Dupixent.

Last quarter, revenue unexpectedly fell by around 3.7%. Dupixent is a monoclonal antibody that targets IL-4 and IL-13. Itepekimab targets IL-33.

Risks

Investors are pricing in the risks of a delay for an Itepekimab market application. Instead of adding up to $6 billion in revenue, the company may need to rely on current products for the single-digit percentage growth.

Eylea is a mature product that faces biosimilar competition. Product pricing will continue to erode, hurting profit margins.

The economic prospects for the drug sector continue to worsen. President Trump indicated several times his displeasure with high drug prices. Investors should expect The White House to continue to target the drug manufacturers and pharmacy benefit management markets. As a result, drug companies like Merck (MRK), Bristol-Myers Squibb (BMY), Pfizer (PFE), and GSK (GSK) may underperform the overall market.