Merck Stock Dips 2.16 Percent Despite Positive Pipeline Updates

Merck & Co.'s stock fell 2.16 percent in after-hours trading on October 5, 2026, closing at EUR 125.19. The decline came after the stock had previously closed at EUR 127.96, according to Lang & Schwarz.

Despite the drop, Merck reported promising developments in its pipeline. On September 30, 2026, the company announced positive results from its Phase 2b study of tulisokibart, an investigational treatment for hidradenitis suppurativa. The study met its primary endpoint, with 72 percent of patients in the high-dose group and 64 percent in the medium-dose group achieving HiSCR50 at week 16, compared to 35 percent in the placebo group. Merck stated that these results will guide the Phase 3 development of the drug.

Additionally, on September 28, 2026, Merck entered an exclusive global license agreement with SciBrunch Therapeutics for SPR2015, a preclinical oral KRAS G12D inhibitor. The deal includes a $400 million upfront payment and potential milestone payments totaling up to $2.13 billion. Merck plans to record a $400 million pretax charge in its third-quarter 2026 results due to this agreement.