Personalized mRNA vaccine reduces melanoma return in trial

A personalized mRNA cancer vaccine developed by Moderna and Merck reduced the risk that high-risk melanoma would return or spread when used with an established immunotherapy drug, the companies said, marking the first positive late-stage trial result for an mRNA cancer vaccine.

The vaccine, called Intismeran, was tested alongside Keytruda, Merck’s immunotherapy treatment, in patients who had undergone surgery for high-risk melanoma, a serious form of skin cancer. The companies said interim results from a phase three trial showed the combination significantly extended the time patients remained cancer free compared with Keytruda alone and reduced the risk of the disease spreading to other organs.

The study involved more than 1,000 patients with high-risk stage two, three or four melanoma, ranging from large tumors confined to one area to cancers that had already spread to other parts of the body. Moderna and Merck said the trial met both goals: reducing recurrence and preventing tumor spread. Detailed results have not yet been released or peer-reviewed, and Moderna said they are expected to be presented at an upcoming medical meeting.

The treatment is designed for each patient. Scientists remove a small piece of a patient’s tumor, sequence its DNA and use mRNA technology to create a vaccine that targets specific mutations in that person’s cancer cells. The goal is to train the immune system to recognize and attack any tumor cells that remain after surgery.

Moderna Chief Executive Stephane Bancel called the findings a “pivotal moment” in cancer research. Moderna President Stephen Hoge said thousands of patients who have had high-risk melanoma tumors removed in surgery could benefit by next year if regulators approve the treatment, Al Jazeera reported. Merck said the companies are already in talks with regulators.

Cancer specialists described the results as promising but urged caution because the full data have not been published or reviewed by independent experts. Dr Talisia Quallo, head of prevention and early detection at Cancer Research UK, said the research “shows promise” but said the interim data still need full review.

“It’s vital that research like this continues to be funded so that more people with cancer can have personalised treatment options to help them live longer, better lives,” she said.

Dr Lennard Lee, a consultant medical oncologist and associate professor at the University of Oxford, said the findings had implications beyond melanoma. “This is certainly good news for patients with melanoma, but the study has much wider implications,” he said. “It provides proof of principle that personalised cancer vaccines work.”

Karen Knudsen, CEO of the Parker Institute for Cancer Immunotherapy, told Al Jazeera the results could point to a new phase in treating solid-tumor cancers. “The positive hit here leads us into truly this next phase in immunotherapy,” she said. “This is an auspicious start – this is where things begin.”

Even if the trial process is completed successfully, the treatment would still require regulatory approval. In the United Kingdom, it would then need to go through another approval process before becoming available on the NHS, the BBC reported.

The announcement sent investor interest sharply higher. Al Jazeera reported that Moderna shares surged as much as 160 percent, while the BBC reported that shares in both Moderna and Merck rose after the announcement.

Moderna and Merck are also testing similar personalized vaccines for other cancers. The BBC reported trials involving lung, bladder and kidney cancers, while Al Jazeera reported similar approaches are being tested against lung, breast and pancreatic cancers.