Moderna and Merck's Breakthrough Melanoma Vaccine Revives Promise for mRNA Technology

A personalised vaccine developed by Moderna and Merck successfully reduced the recurrence of melanoma in a large, late-stage trial, boosting expectations for treating the deadliest form of skin cancer and highlighting the potential of mRNA technology.

As reported by Bloomberg, the trial achieved its primary goal when the vaccine, combined with Merck’s immune drug Keytruda, prevented cancer from returning more frequently than immunotherapy alone following surgical removal. The companies announced on Wednesday that the treatment also slowed the spread of the cancer to new areas of the body.

Following the announcement, Moderna shares surged by a record 177 per cent, though the stock remains well below its pandemic-era peaks. Meanwhile, Merck shares climbed nearly 13 per cent. This study represents the first successful final-stage trial for any mRNA-based cancer therapy, offering a major positive development for both organisations and serving as strong evidence that the technology behind Moderna's Covid-era success has a viable future.

For Merck, which faces a looming patent expiration for its best-selling drug Keytruda, the breakthrough introduces an important new market for future growth. Jedd Wolchok, a melanoma expert and director of the Meyer Cancer Centre at Weill Cornell Medicine, noted that the results mark a significant step forward for cancer immunotherapy and vaccines, demonstrating that training the immune system to recognize specific cancer targets can enhance existing immune treatments.

Specific details regarding improvements in recurrence-free survival were not disclosed, and the trial is ongoing to determine whether vaccinated patients live longer. Melanoma remains the most serious form of skin cancer, with the American Cancer Society estimating approximately 112,000 diagnoses and 8,500 deaths annually in the US.

Executives stated they plan to discuss regulatory approval and present the data at an upcoming medical meeting. Moderna Chief Executive Officer Stéphane Bancel stated in an interview that the personalised vaccine could potentially gain approval as early as 2027.

Despite the milestone, questions persist regarding the cost and feasibility of scaling bespoke cancer treatments. Keytruda alone can exceed $200,000 annually for certain cancers, while other individualised therapies like CAR-T for blood cancers can cost over half a million dollars.

Unlike many treatments tested initially on critically ill patients, this melanoma vaccine was administered to individuals whose tumours were completely removed during surgery. The personalised vaccine, named intismeran autogene, relies on mRNA technology to customise treatments based on individual tumour mutations, a process taking approximately six weeks per patient.