Merck Stock Pulls Back After Reaching All-Time High on Promising Cancer Vaccine Data

Merck & Co., Inc.'s stock price has pulled back slightly after reaching an all-time high of $151 earlier in the day, down 1.30 percent to $147.60 as of August 28, 2026.

The decline comes on the heels of promising phase 3 data for its personalized cancer vaccine used in combination with Keytruda, which significantly extended the time high-risk melanoma patients remained cancer-free compared to Keytruda alone.

Merck reported total sales of $16.6 billion in Q2 2026, a 5 percent year-over-year increase driven by expansion of its immuno-oncology and vaccines franchises.

Keytruda generated $8.4 billion in revenue in Q2 2026, up 5 percent from the same period last year, highlighting the drug's dominance as Merck's growth engine.