Merck Stock Gains on Positive Melanoma Vaccine Data

Merck & Co. stock saw a 1.6% gain on September 1, 2026, closing at $150.17 USD in New York trading.

The company's focus on oncology was sharpened by new data from its personalized melanoma mRNA vaccine in combination with Keytruda, its established PD-1 immunotherapy.

A randomized trial showed that adding the vaccine reduced the relative risk of recurrence or death by 49% and distant metastasis or death by 59% compared to Keytruda alone.

This is significant because it supports earlier interim findings and provides late-stage confirmation for Merck's oncology strategy.