Regeneron Hit with Securities Class Action Over Melanoma Trial Protocol Changes and Failure
REGN sits 25% above its 52-week low of $541.
Summary
A securities class action lawsuit has been filed against Regeneron, alleging the company misled investors about the prospects of its Phase 3 melanoma trial for fianlimab plus Libtayo. The suit claims management concealed flawed statistical assumptions and slow event rates while expressing confidence, then abruptly disclosed protocol changes in April 2026 and trial failure on May 15, 2026, wiping out $11 billion in market cap. This follows the May 15 trial failure news and adds legal risk. The lead plaintiff deadline is September 14, 2026. While the underlying trial outcome is known, the lawsuit introduces potential financial liability and reputational damage.
At the time of this announcement, REGN was trading at $674.90 on NASDAQ in the Life Sciences sector, with a market capitalization of approximately $70.8B. The 52-week trading range was $541.00 to $821.11. This news item was assessed with negative market sentiment and an importance score of 7 out of 10. Source: PR Newswire.