Personalized Cancer Vaccine Cuts Melanoma Return
In a late-stage trial of 1,137 patients, Merck and Moderna's mRNA vaccine, built from each patient's own tumor and given with Keytruda, cut the risk of melanoma returning or death by 42% compared with Keytruda alone. The results have not yet been peer-reviewed.
A cancer vaccine tailored to each patient's tumor cut the risk of melanoma returning or the patient dying by 42% in a Phase 3 trial. Merck and Moderna's intismeran is an mRNA shot that uses information from a patient's own tumor to train the immune system to recognize cancer cells. It was given with Merck's immunotherapy Keytruda.
The trial enrolled 1,137 people whose stage IIB to IV melanoma had been surgically removed. After a median follow-up of about two years, 82.2% of those on the combination had no recurrence, compared with 70% on Keytruda alone. The risk of the cancer spreading to distant organs or death fell 38%. Serious side effects were about as common in both groups, at 14.2% and 13.4%.
The companies released the numbers early after a data leak, ahead of a presentation at the European Society for Medical Oncology congress in Madrid. The results have not been published in a peer-reviewed journal, and overall survival data are not yet mature. The companies say they are "engaging with authorities," the BBC reported.
Madrid — A personalized mRNA cancer vaccine given alongside a standard immunotherapy cut the risk of melanoma returning or death by 42% in a large trial of patients whose tumors had been removed by surgery.
What the trial found
The INTerpath-001 trial enrolled 1,137 adults with completely removed high-risk melanoma, stage IIB through IV. Of them, 757 received intismeran autogene, developed by Merck and Moderna, plus Merck's Keytruda (pembrolizumab); 380 received Keytruda and a placebo, Healio reported. After a median follow-up of 24.6 months, the combination reduced the risk of recurrence or death by 42% (hazard ratio 0.58) and the risk of distant spread or death by 38% (hazard ratio 0.62).
At two years, 82.2% of patients on the combination were free of recurrence, against 70% on Keytruda alone; 88.5% were free of distant spread, against 80.2%. Overall survival data are immature, though investigators reported what they called a favorable trend.
How the treatment works
Each vaccine is personalized, using information from the patient's own tumor to help the immune system recognize cancer cells and target them if they return, the BBC reported. Patients received the vaccine every three weeks for up to nine doses, with Keytruda every six weeks, for about 56 weeks in all.
Side effects and what comes next
Nearly all patients had treatment-related side effects, most often fever, injection-site pain and fatigue. Grade 3 or higher events occurred at similar rates: 14.2% with the vaccine and 13.4% without. "The INTerpath-001 findings support a fundamentally new and individualized approach to treating resected melanoma," said Georgina Long, the trial's principal investigator and medical director of Melanoma Institute Australia.
Alan Melcher of the Institute of Cancer Research in London, who was not involved, called the results "very impressive" but said "we shouldn't get ahead of the evidence" and that longer follow-up is needed to judge survival, the BBC reported. The data were set for an ESMO presidential symposium on October 24; the companies released them early after a leak on October 22. They have not yet been published in a peer-reviewed journal. The same approach is being tested in lung, kidney, bladder and other cancers.