The technology that rushed COVID-19 vaccines to clinics in record time has found a second calling. mRNA-based treatments are now holding melanoma in check for years and showing early wins against pancreatic and brain tumors, cancers long thought untouchable by the immune system.
Key Takeaways:
- A Moderna-Merck personalized mRNA vaccine paired with immunotherapy has kept high-risk melanoma at bay for five years, cutting the risk of recurrence or death by 49% versus immunotherapy alone.
- Researchers are pushing mRNA cancer treatments into trials for pancreatic, brain, lung, kidney and bladder cancers, with one market forecast putting personalized cancer vaccines at $8.5 billion a year by 2034.
- The U.S. Department of Health and Human Services cut $500 million from mRNA vaccine projects, even as the National Cancer Institute backs a $200 million partnership funding mRNA cancer trials.
The progress arrives at an odd moment, with U.S. health officials sending mixed messages about whether the same technology deserves trust or suspicion.
Cancer vaccines are one of the fastest-growing corners of oncology research. More than 130 studies on the approach were presented this month at the American Society of Clinical Oncology meeting in Chicago.
Moderna and Merck are at the forefront of this technological trend. Their treatment combines a potent immunotherapy drug with an experimental, made-to-order mRNA vaccine, and it has kept melanoma in remission for five years, a landmark for the idea of teaching the immune system to hunt cancer.
These companies are running nine large and midsize trials in lung, kidney, bladder and pancreatic cancers, and early results from their big confirmatory melanoma trial could arrive this year. The melanoma data itself is impressive: in the mid-stage study, roughly 69% of patients who got the combination stayed cancer-free after five years, compared with about 49% on immunotherapy alone, a difference that has analysts watching the looming Phase 3 readout closely.
Other players have moved early lab work into full programs, including Roche and BioNTech. Market research firm Vision Research Reports projects that personalized cancer vaccines, driven largely by mRNA, could hit $8.5 billion in annual sales by 2034.
The logic borrows from infectious disease. Some vaccines train the immune system to spot and destroy a virus, granting lasting protection. “That principle can now be applied to cancer, and that's a big advance,” said Merck Chief Medical Officer Eliav Barr.
The momentum runs against the political current. The U.S. Department of Health and Human Services, led by anti-vaccine activist Robert F. Kennedy Jr., cut $500 million in mRNA vaccine projects. Kennedy has attacked the safety and efficacy of mRNA vaccines without evidence and made exaggerated claims about side effects. Yet the National Cancer Institute is working with the Foundation for the National Institutes of Health on a $200 million public-private partnership to fund promising cancer vaccine trials, mRNA ones among them. An HHS spokesperson defended Kennedy's position on mRNA for infectious diseases but said he sees promise in the technology for preventing cancer recurrence, pointing to that partnership.
Splitting mRNA research into separate boxes worries scientists, who note the technology was given safely to more than 700 million people during the pandemic. The skepticism has already left a mark on the field: Moderna scaled back, discontinuing three vaccine candidates in late 2025 after dozens of government-funded mRNA contracts were canceled, even while doubling down on its cancer work. “We have to be able to innovate around technologies that are going to improve healthcare for all,” said Dr. Elias Sayour, who directs an RNA engineering lab at the University of Florida and advises the NCI's cancer vaccine effort. “If we don't do it, other countries will.”
From a hunch to a possible breakthrough
Ten years ago, Dr. Vinod Balachandran of Memorial Sloan Kettering Cancer Center was among the first to bet on mRNA against the deadliest cancers. He noticed something curious: in rare cases, patients survived pancreatic cancer, a disease scientists assumed was invisible to the immune system. Studies showed that in those survivors, the immune system had learned to recognize and attack the tumors. The puzzle was how to make that the rule rather than the exception.
Balachandran reasoned that mRNA, fast to produce, could power custom vaccines built around the specific mutations found only on a patient's tumor after surgery. A phase 1 trial of 16 patients launched in December 2019, pairing chemotherapy, Roche's immunotherapy Tecentriq, and a tailored BioNTech mRNA vaccine aimed at each patient's mutated proteins. At the American Association for Cancer Research meeting in April, he reported that of the eight pancreatic cancer patients whose immune systems responded to the vaccine, seven were still alive up to six years later. A 260-patient global phase 2 trial is now underway to confirm the finding.
“What a breakthrough it would be if mRNA was the technology that finally was able to achieve an immune response that was clinically meaningful,” said Dr. Robert Vonderheide, director of Penn Medicine's Abramson Cancer Center and AACR's president-elect.
The body's software
Messenger ribonucleic acid sits in every cell. Its everyday job is ferrying genetic instructions from the cell nucleus to the machinery that builds specific proteins. Sayour calls mRNA the software of the human body. It can be reprogrammed for many tasks, including making proteins that teach the immune system to attack pathogens or rogue cancer cells.
That kind of work is happening at Mount Sinai, where Brian Brown, director of the Icahn Genomics Institute, has developed a way to design lipid nanoparticles, the fat bubbles that ferry mRNA into cells, so they steer the cargo to specific parts of the body. A study published in Nature Biotechnology in April suggests mRNA can be turned up or down to boost the immune response or calm harmful reactions, opening doors to stronger cancer treatments or new approaches for autoimmune disease.
Sayour has built a vaccine that injects clusters of lipid nanoparticles into glioblastoma patients, rather than the single nanoparticle used in COVID vaccines. Delivered intravenously, it aims to rapidly rouse the immune system against the fast-growing brain cancer, which carries a 5-year survival rate under 7%. Beating a cancer like glioblastoma is a tall order for a vaccine, Sayour admitted. But, he said, “if it can cure or even make a dent in glioblastoma, the implications for all forms of human cancer, in my mind, are extraordinary.”
Written by Vytautas Valinskas