Trial Finds Lower Melanoma Recurrence Risk With Personalized Vaccine
A personalized mRNA vaccine, given alongside an existing immunotherapy drug, reduced the risk of melanoma returning or causing death in a Phase 3 clinical trial reported by Merck and Moderna. The vaccine is intended for patients who have already undergone treatment, not to prevent melanoma from developing.
The INTerpath-001 trial enrolled 1,137 people whose high-risk melanoma had been completely removed through surgery. Participants received either pembrolizumab, an immunotherapy drug, or pembrolizumab combined with the experimental vaccine, called intismeran autogene.
After an average follow-up of 24.6 months, the combination group had a 42 percent lower risk of recurrence or death than the group receiving pembrolizumab alone. Researchers also reported a 38 percent lower risk of the cancer spreading to other parts of the body. At the end of follow-up, 82.2 percent of patients given both treatments remained free of recurrence, compared with 70 percent of those given only pembrolizumab.
Each vaccine was made using a sample of the patient’s tumor. Researchers identified mutations that could produce proteins recognizable by the immune system, then selected up to three molecular targets for that patient’s vaccine. This individualized process distinguishes the treatment from a vaccine designed for general use.
Some trial participants experienced fever, fatigue or pain at the injection site. The companies said the combination’s safety findings were similar to those seen in earlier trials.
Researchers not involved in the study described the findings as an advance for personalized cancer treatment, while noting that manufacturing individual vaccines at scale could be costly and logistically difficult. The treatment remains under investigation and would require regulatory approval before widespread use.
The findings concern patients with surgically removed, high-risk melanoma. Whether a similar approach will work for other cancers remains a question for further research. Long-term follow-up will also help clarify how durable the reported benefit is.