Stock Market Update

[BRIEFING.COM] The S&P 500 (-0.3%), Nasdaq Composite (-0.7%), and DJIA (flat) remain mostly lower at midday.

The health care sector (-0.1%) is modestly lower, pressured by weakness in Regeneron Pharma (REGN 625.62, -72.64, -10.40%) after the company reported that its Phase 3 trial evaluating fianlimab in combination with cemiplimab for first-line unresectable or metastatic melanoma failed to achieve statistical significance on the primary endpoint of progression-free survival versus pembrolizumab monotherapy. While the dataset showed encouraging efficacy trends in the high-dose arm, investors viewed the result as a major disappointment given expectations for a potentially important new immuno-oncology growth platform.

The sharp sell-off likely reflects concerns that REGN may now face a more complicated regulatory and commercial path in melanoma, particularly against increasingly established competitors like Keytruda and Opdualag.