Merck & Co. Stock Surges as Keytruda Faces Biosimilar and Trial Pressure
Merck & Co.'s stock has reached near its 52-week high of $156.92 USD, trading at around $152.32 as of early September 2026 on the New York Stock Exchange.
The company's valuation is approximately $369.73 billion USD according to market data compiled by ad-hoc-news and stock portals as of September 2, 2026.
Keytruda, Merck's flagship immunotherapy drug, faces biosimilar and trial pressure with a new partnership between India-based Cipla and China's Qilu Pharmaceutical for the U.S. market of Keytruda, which generated over $31 billion USD in sales in 2025.
Additionally, clinical trial data from Summit Therapeutics' partner Akeso shows that ivonescimab monotherapy delivered a statistically significant survival advantage over Keytruda in PD-L1-positive patients with advanced non-small cell lung cancer.