Shares of vaccine developers surged in premarket trading on Wednesday after Moderna and Merck reported positive results from a late-stage trial of a personalized melanoma vaccine.
Moderna’s stock climbed as much as 86% ahead of the market open, while Merck advanced 8.7%. BioNTech rose 7.5% and Novavax added 4.0% in premarket activity. The gains reflected investor optimism following the trial outcomes, which demonstrated a reduction in melanoma recurrence.
The personalized cancer vaccine, developed in collaboration between Moderna and Merck, targets melanoma, a form of skin cancer. The trial’s positive results were disclosed in a statement published on Wednesday, August 19, 2026, and contributed to broader strength in vaccine-related equities.
The surge in Moderna’s shares underscored the market’s reaction to the trial’s potential implications for cancer treatment and the company’s pipeline. Analysts and investors closely monitor such developments for their impact on valuation and future revenue prospects in the biotechnology sector.
