Merck and Moderna Cancer Vaccine Trial Yields Promising Results

Merck and Moderna have announced positive results from their late-stage trial of an experimental personalized cancer vaccine. The mRNA-based shot, combined with Merck's immunotherapy Keytruda, met its main goal in a phase three trial involving over 1,100 patients with advanced melanoma. The treatment significantly extended the time patients lived without their melanoma returning compared to using Keytruda alone.

The combination regimen also reduced the risk of cancer spreading to distant parts of the body. These results build on positive phase two trial data from earlier this year. Merck and Moderna plan to present the full data at an upcoming international medical meeting, but it's unclear when they will submit applications for approval in the U.S.

Merck shares rose over 8% in premarket trading, while Moderna's stock soared about 90%. The personalized vaccine is designed to target specific mutations in each patient's tumor rather than using a one-size-fits-all approach. Merck's head of oncology early development, Dr. Jane Healy, called the results 'very exciting' and noted that side effects were similar to other vaccines.