Cancer treatments have been veering toward more personalized approaches that recruit the immune system, and the latest results involving an mRNA-based therapy from Moderna and an immunotherapy from Merck show that combining them may result in significant benefit for certain cancer patients.
In a release, the two companies report that people with melanoma who received Moderna’s therapy, intismeran, and Merck’s pembrolizumab (Keytruda), lived longer without any recurrence of their cancer, as well as had fewer incidences of their cancer spreading, compared to those receiving Keytruda alone, which is the current standard treatment. Combining the two therapies seems to lead to better outcomes in this later-stage trial. Moderna’s intismeran is not yet approved, while Merck’s Keytruda was first approved to treat melanoma in 2014, and in 2019 to treat melanoma in people after tumors were removed. The current study included people in this latter group with stage 2 to stage 4 melanoma who were treated with either intismeran and Keytruda or Keytruda alone after surgeons removed the bulk of their tumors.
“What we’re trying to do here is to tell the immune system that it missed the signature of the tumor cell if you have cancer,” Moderna CEO Stephane Bancel tells TIME of intismeran. “This product basically allows us to teach the immune system about the mutation in your cancer that allows the cancer to grow.”
The study involved 1,137 people with stage 2 to stage 4 melanoma who received surgery then were randomly assigned to receive either the combination of therapies or Keytruda for just over a year. Intismeran is the first of its kind autogene therapy that relies on studying a patient’s cancer mutations, making mRNA sequences of those mutations and giving them back to the patient in so their immune systems can recognize the tumor signals in the same way it would a virus—in what’s known as a therapeutic vaccine. One of the advantages of the mRNA platform is its ability to generate such genetic sequences relatively quickly, in a matter of weeks, which is essential for scaling up more personalized cancer treatment approaches. Keytruda works by unveiling the cancer cells, which can often hide from the immune system since they start out as normal cells before picking up mutations that make them grow out of control.
The companies did not provide specific details about the recurrence or survival rates, but earlier this year reported at ASCO, a major cancer conference, from an earlier stage study that showed that the combination lowered the risk of recurring melanoma by 49% and lowered the risk of distant spread of the cancer or death by 59%.
The latest results bring some good news to Moderna, which has seen its stock drop after reaching highs during the COVID pandemic following development of the first mRNA vaccine, against SARS-CoV-2. In 2025, Bancel laid off 10% of the workforce, amounting to 500 to 800 employees worldwide, after a combination of sagging sales from the COVID shot and loss of important government contracts to develop pandemic flu vaccines based on mRNA technology. In August, the U.S. Food and Drug Administration (FDA) approved the first mRNA flu shot, developed by Moderna, but only after initially refusing to review the company’s submission.
Bancel says that Moderna is also exploring using intismeran alone, perhaps in earlier stage cancers. For the current trial, because intismeran is still an experimental therapy under study, and an approved therapy, Keytruda, does exist for melanoma patients, regulators at the FDA were more comfortable with combining the drugs so every patient received at least the standard of care and therefore would not be additionally harmed by joining the study. “It would be unethical for us to tell people to come on a study of something that we don’t know if it works, when people are fighting for their lives,” he says. “That’s why we did the study together with Keytruda, which can improve outcomes, and we tried to show that the combination was better, and we did.”
Bancel’s teams are already studying intismeran in stage 1 lung cancer, to see if using it earlier, and priming the immune system, can lead to equally beneficial outcomes for those people. In lung cancer, standard treatment involves surgery and careful monitoring for any signs of returning cancer, so doctors can ethically study how adding intismeran for some patients affects their cancer outcomes compared to those not receiving it. While that study is still in early stages, Bancel is optimistic since “from a scientific standpoint there is no scientific sense that it would work in melanoma and not work in another tumor type,” he says of the mRNA-based approach. “I think it will be transformational. Think about if you get a screening X-ray and find stage 1 lung cancer. Then you get intismeran, which is like a vaccine so you have no severe toxicity like with other immunotherapy. Think about getting this product on your way to work, or even [potentially] at your local pharmacy—that would be an incredible change in care. And it can help reduce the risk of metastasis, and have a profound impact on patients, as well as prevent people from getting very severe disease.”
Moderna is also studying intismeran in stage 3 lung cancer, and hoping to see similarly encouraging results as they did in melanoma patients. And its scientists are studying the compound in kidney, pancreas, and bladder cancers in nine ongoing studies, says Bancel.
“Because of all the things we learned over the years in the field of immunology, we believe this molecule will be used in many different cancer types,” he says.
The post Promising Results for mRNA Cancer Vaccine from Moderna and Merck appeared first on TIME.
