Merck Shares Surge Near 52-Week High on Cancer Vaccine Data

Merck & Co., Inc. (ISIN US58933Y1055) shares have been trading near a fresh 52-week high in late August 2026, supported by new Phase 3 data for its personalized mRNA cancer vaccine that builds on the company's blockbuster immunotherapy Keytruda.

The recent data shows statistically significant improvements in recurrence-free survival and distant metastasis-free survival compared to Keytruda alone in a large melanoma trial. Patients receiving the personalized vaccine plus Keytruda experienced significantly lower rates of cancer recurrence than those treated with Keytruda alone.

Keytruda's $31.7 billion global sales last year make it the world's top-selling drug by revenue, according to South Korean business media. Its substance patent is scheduled to expire in Korea in 2028 and in Europe in early 2031.