Moderna, Merck melanoma vaccine success offers fresh hope for cancer care

The revolutionary mRNA technology that enabled the rapid development of COVID-19 vaccines is once again at the centre of a major medical advance, with two pharmaceutical giants joining forces to tackle one of the most devastating illnesses of our time.

Moderna and Merck have announced promising results from a late-stage trial of their personalised mRNA cancer vaccine, Intismeran, in patients with melanoma, Reuters reports, with the news sending Moderna’s shares sharply higher as investors responded to the results.

According to the companies, the vaccine reduced the risk of melanoma returning or spreading in patients who had undergone surgery to remove their tumours, marking a major milestone for the emerging field of personalised cancer vaccines.

Interim results released on August 19 showed that the treatment met both primary goals of reducing cancer recurrence and preventing the spread of tumours. The companies have not yet released the detailed findings, which are expected to be presented at an upcoming medical meeting.

Moderna President Stephen Hoge said thousands of patients who have had high-risk melanoma tumours surgically removed could potentially benefit from the treatment as early as next year if the vaccine receives regulatory approval.

Developed by Moderna in partnership with pharmaceutical giant Merck, the experimental vaccine was tested in combination with Merck’s immunotherapy drug Keytruda.

The vaccine is designed to train a patient’s immune system to identify and attack cancer cells by targeting mutations specific to their tumour.

Similar approaches are being investigated as potential treatments for other cancers, including lung, breast and pancreatic cancer.

Previous studies have suggested that mRNA vaccines could help the immune system recognise and attack cancer cells, with evidence emerging from experiments in mice as well as analyses of medical records from cancer patients.

The latest results represent the first positive late-stage trial result for an mRNA cancer vaccine, according to Merck. The companies have already begun discussions with regulators about potential approval of the treatment.

Needed revival for Moderna

Moderna’s shares surged following the announcement, with the company’s stock rising around 160%.

According to an article by the Financial Times, the surge represents a dramatic turnaround for Moderna. For much of the previous year, the company had been among the most heavily shorted stocks in the S&P 500 and faced significant pressure from US Health Secretary Robert F. Kennedy Jr.

Kennedy, who has openly raised concerns about several vaccines, cancelled funding in 2025 for mRNA vaccines being developed to protect against respiratory viruses, dealing a blow to Moderna, Pfizer and other companies developing the technology.

After a difficult 2025, Moderna is now among the best-performing companies in the S&P 500 index on the American stock exchange.

The turnaround is being driven in part by a pipeline of experimental cancer vaccines being developed by the Cambridge, Massachusetts-based company. Several of the treatments use messenger RNA, the genetic material that acts as a molecular courier within the body.

By Nazrin Sadigova