Key takeaways:
- Phase 3 trial finds personalized intismeran plus pembrolizumab may better prevent high-risk melanoma recurrence after surgery
- The trial enrolled 1,137 patients and builds on phase 2 results showing about half the recurrence risk
- Moderna and Merck plan to present detailed findings and pursue potential regulatory approval for the treatment
New research from a phase 3 clinical trial is showing further promising results for preventing melanoma recurrence after surgery.
Intismeran, a personalized mRNA vaccine, helped prevent the deadly skin cancer from returning and allowed those with high-risk disease to live longer, trial data showed.
Moffitt Cancer Center was among the participating research sites in the trial developed by Moderna and Merck, which enrolled 1,137 patients with high-risk melanoma following surgery.
"Moffitt played a major role in the conduct of the phase 3 trial that enrolled and treated patients at our center," said Ahmad Tarhini, MD, PhD, Moffitt's Cutaneous Clinical and Translational Research director. "This immunotherapy regimen is bound to change the standard of care pending FDA approval."
Tarhini served as Moffitt's site principal investigator and has led several studies in adjuvant therapy over the years.
How it Works
The trial consisted of using intismeran, a personalized cancer vaccine immunotherapy designed and produced using genetic information from a patient's own tumor, combined with pembrolizumab (Keytruda), an immunotherapy drug that is widely used to reduce the risk of melanoma recurrence.
Moffitt Cancer Center was among the participating research sites in the trial.
After a piece of the patient's tumor is removed, it is analyzed in the lab to identify any unique mutations. That information is used to make the mRNA vaccine, which delivers synthetic mRNA into cells. While Keytruda harnesses the immune system to recognize the cancer, the vaccine helps train the immune system to attack.
The mRNA technology played a major role in the development of the Covid-19 vaccine and reignited research into therapeutic cancer vaccines.
In the phase 3 trial, researchers found the combination treatment could provide additional protection against melanoma returning or spreading to other parts of the body.
The latest findings build on earlier results showing that, after five years, patients who received intismeran combined with Keytruda had about half the risk of melanoma recurrence compared to those who received Keytruda alone. The results from the phase 2 trial were presented at the 2026 American Society of Clinical Oncology Annual Meeting.
Impact on Standard of Care
Merck and Moderna say they plan to present detailed data from the trial at an upcoming international medical meeting and engage with regulators on potential filings for approval.
"By intervening earlier in the course of disease, when many cancers are considered most treatable, the goal of adjuvant therapy given after surgery is to increase the possibility of cure for more patients," said Dean Y. Li, MD, PhD, Merck Research Laboratories president.
Previous findings shared this summer showed patients who received intismeran with Keytruda were less likely to have their melanoma return.
Melanoma is considered the deadliest form of skin cancer because of its ability to grow and spread quickly. The American Cancer Society estimates that about 112,000 new cases of melanoma will be diagnosed in the United States in 2026.
The personalized mRNA vaccine approach is also being tested to prevent the recurrence of lung and other cancers.
Moffitt remains dedicated to advancing innovative cancer research and developing new approaches that can help prevent cancer from returning, with the ultimate goal of improving outcomes and saving more lives.
Medically reviewed by Ahmad Tarhini, MD, P
News – Curated by Amanda Scott, Alias Group Creative
Follow her on Bluesky
Melanoma mRNA Vaccine Shows Promise in Preventing Disease Recurrence
Key takeaways: Phase 3 trial finds personalized intismeran plus pembrolizumab may better prevent high-risk melanoma recurrence after surgery The trial enrolled 1,137 patients and builds on phase 2 results showing about half the recurrence [...]
Scientists Discover a Powerful New Weapon Against a Dangerous Gut Infection
The promise of an experimental treatment for C. difficile gut infections lies partly in the bacteria it leaves alive, according to early laboratory and mouse research. Broad-spectrum antibiotics can disrupt the gut’s microbial community, [...]
Your Bones May Hold a Hidden Clue to Blood Cancer Survival
For people with blood cancers called myelodysplastic syndromes, osteoporosis may hold an overlooked clue to survival, a three-year observational study suggests. In blood cancers that develop in the bone marrow, an important clue to [...]
Researchers Discover What Reading for Pleasure May Be Doing to Your Brain
Reading for pleasure may offer surprising benefits for the brain, with research linking the habit to better mental health, stronger cognitive abilities, and a lower risk of dementia. Reading for pleasure may do far [...]
Scientists Discover a Hidden Trigger That Keeps Inflammation Alive
Inflammation persists after proteins detach from immune receptors, revealing a potential target for autoimmune treatments. Since a Nobel Prize-winning discovery in the 1990s identified molecules called Toll-like Receptors as the guardians of the human [...]
A Virus Gives Itself Away the Moment It Attacks
Researchers have found the trigger behind a powerful bacterial defense against viruses. Viruses that prey on bacteria could become an increasingly important tool for treating bacterial infections, particularly as antibiotic resistance makes some infections [...]
Scientists Discover Aspirin May Slash Dementia Risk by 70% – but Only for Certain People
Aspirin was linked to a sharply lower dementia risk in some older adults, and their genes may hold the clue. A Monash University analysis found that older adults with a particular genetic profile had [...]
Inflammation May Awaken Dormant Cancer Cells Years After Treatment
The body’s response to inflammation may disturb cancer cells that have been lying silent for years, giving them an opportunity to grow again. Researchers at the Francis Crick Institute have found that gut inflammation [...]
Where do nanoparticles go once they enter the body?
New international best practice guidance, co-written at ANSTO, sets out how to measure where nanoparticles like titanium dioxide end up in the body and how long they remain. The guidance has been shared by [...]
Long-Acting HIV Shots Could Solve a Major Treatment Challenge for Young People
A major African trial suggests that changing how HIV treatment is delivered could significantly improve viral suppression in adolescents. Young people with HIV were more likely to keep the virus suppressed when they received [...]
WHO Factsheets – The top 10 causes of death
In 2023, the 10 leading causes of death accounted for 33 million deaths, or 54% of the total 61 million deaths worldwide. The top global causes of death, in order of total number of lives lost, [...]
Aging Cells May Be Hiding From the Immune System – Scientists Think They Know How
Your immune system is supposed to clear out damaged cells. Researchers may have found how some of them hide and linger as the body ages. Researchers led by Cedars-Sinai Health Sciences University have identified [...]
Your Voice May Reveal How Fast Your Brain Is Aging
Researchers have developed a machine-learning “speech clock” that estimates age from subtle patterns in how people speak and what they say. It is possible that people’s voices may contain certain signals of aging that [...]
Optogenetics Pioneers Win 2026 Nobel Prize in Physiology or Medicine
The 2026 Nobel Prize in Physiology or Medicine has been awarded to Peter Hegemann, Georg Nagel, and Karl Deisseroth for the development of optogenetics, a revolutionary technology that uses light to control individual neurons [...]
Molecular Manufacturing: The Future of Nanomedicine – From NanoappsMedical Inc.
This book explores the revolutionary potential of atomically precise manufacturing technologies to transform global healthcare, as well as practically every other sector across society. This forward-thinking volume examines how envisaged Factory@Home systems might enable the cost-effective [...]
What is ‘American Covid’ and how bad is it?
Cases of so-called ‘American Covid’ are on the rise in the UK. The strain is officially called XFG, or ‘Stratus’, and is the most common variant in North America, hence the name. It might soon [...]
