Breakthrough for Moderna and Merck: Promising Results in Advanced Melanoma Vaccine Trial

An experimental personalized cancer vaccine for melanoma from Merck and Moderna has shown positive preliminary results in its first advanced-stage trial, it was announced on Wednesday. The results bring the companies one step closer to submitting an application to the U.S. Food and Drug Administration (FDA) for treatment approval. Following the announcement, their shares surged on Wall Street.

The vaccine, based on mRNA technology, was administered in combination with Merck's immunotherapy drug Keytruda and met the primary endpoints of the Phase 3 trial. The study included more than 1,100 patients with high-risk or advanced melanoma whose detectable tumor had been completely removed by surgery. The combination treatment significantly extended the duration of time patients lived without the cancer returning compared to treatment with Keytruda alone, and also reduced the risk of the cancer spreading to distant areas of the body.

These results build on positive data from a Phase 2 trial published earlier this year. The companies plan to present the findings at an upcoming international medical conference, though it remains unclear when they intend to file for U.S. approval. Nevertheless, the preliminary data suggest that this combination could become a new treatment option for melanoma—a type of cancer that accounts for only about 1% of skin cancer cases but the vast majority of deaths from them.

Most melanoma recurrences occur within the first two to three years after initial treatment. Dr. Jane Healy, head of early oncology development at Merck, stated:

"Melanoma patients are forced to deal with the new and difficult reality that a diagnosis brings, and then undergo unpleasant treatments like surgery, and after all that they are still afraid that the cancer will return."

Healy described the results as "very exciting," noting that the treatment led to a "clinically meaningful improvement" over the standard of care, with side effects similar to those of other common vaccines. She added that the results provide a significant boost to the personalized treatment approach that Merck and Moderna have been developing for decades.