Moderna and Merck cancer vaccine shows promising melanoma results

Moderna and Merck have reported encouraging results from a late-stage trial of a personalised mRNA cancer vaccine, saying the treatment significantly reduced the risk of melanoma returning or spreading.

The vaccine, known as Intismeran, met both primary goals of the trial, according to interim findings released on Wednesday. Researchers found that the treatment reduced the likelihood of cancer recurrence and helped prevent the disease from spreading to other parts of the body.

The companies have not yet released detailed trial data. Further findings are expected to be presented at an upcoming medical conference.

The results represent a major milestone for mRNA technology, which gained widespread attention through COVID-19 vaccines but is now being investigated as a potential treatment for cancer and other diseases.

Moderna President Stephen Hoge said thousands of people who undergo surgery to remove high-risk melanoma tumours could potentially benefit from the vaccine as early as next year if regulators approve it.

More than 1.5 million people in the United States were living with melanoma in 2023, according to the National Cancer Institute.

The vaccine was developed jointly by Moderna and Merck and was tested alongside Merck's immunotherapy drug Keytruda. Rather than targeting cancer directly, the personalised vaccine is designed to train the body's immune system to recognise and attack cancer cells carrying specific mutations.

The approach is tailored to individual patients, with the vaccine designed around mutations identified in their tumours.

Scientists are also investigating similar mRNA-based approaches against other cancers, including lung, breast and pancreatic tumours.

Earlier research has provided evidence that mRNA vaccines could help the immune system identify and attack cancer cells. Studies in animals and analyses of patient medical records have offered encouraging signs, although researchers have stressed the need for results from large clinical trials.

The latest findings are particularly significant because they represent the first positive late-stage trial result for an mRNA-based cancer vaccine.

Merck said the two companies have already begun discussions with regulators about the treatment and its potential approval.

The announcement triggered a sharp rise in Moderna's shares, which surged as much as 160 percent during trading.

While the preliminary results are highly encouraging, the full trial data will be closely examined by researchers and regulators before the vaccine's effectiveness and safety can be fully assessed.

If the findings are confirmed in the detailed analysis and the treatment receives regulatory approval, the vaccine could represent a significant advance in personalised cancer care and broaden the use of mRNA technology beyond infectious diseases.