Test results from the combined drug regimen trial of Moderna’s new cancer vaccine and Merck’s cancer immunotherapy drug showed high-risk melanoma patients who used both drugs had significantly reduced risk of death or recurrence compared to using the immunotherapy alone.

Findings of the Phase 2 clinical trial were reported on Sunday in a news release by the American Association for Cancer Research.

NBC News said Moderna’s vaccine uses mRNA technology to target specific mutations in the body, leaving healthy cells alone.

The Washington Post said this vaccine, “combined with Merck’s cancer immunotherapy drug pembrolizumab, marketed as Keytruda, performed well in mid-stage testing in patients battling melanoma.”

“After surgery and as long as a year on the pair of drugs, melanoma patients in the trial saw a 44% reduced risk of recurrence or death compared with patients who received Keytruda alone, according to the announcement,” per The Washington Post.

Trial details

NBC News said 157 melanoma patients who had surgically removed tumors and a high risk of recurrence received the immunotherapy medication; 107 of them were also given Moderna’s vaccine.

Of the 107 who received the vaccine and immunotherapy drug, “the cancer returned in 24 subjects (22.4%) within two years of follow-up, compared with 20 out of 50 (40%) who received Keytruda alone,” Reuters reported.

The vaccine targets up to 34 proteins from tumors, NBC News said.

“That’s like taking 34 shots on goal,” Dr. Thomas Marron, the director of the Early Phase Trials Unit at the Tisch Cancer Institute, told NBC. “You’re teaching the immune system to recognize 34 different things that are unique to that cancer.”

Marron is also an associate professor of medicine at the Icahn School of Medicine at Mount Sinai in New York.

The article said that side effects experienced by all subjects were similar, the most common being fatigue, which was most often reported by those who received the vaccine.

Major milestone

Director of the Tumor Immunology Program at UCLA’s Jonsson Comprehensive Cancer Center, Dr. Antoni Ribas, told NBC News, “It’s the first time a cancer vaccine has been shown to have this level of benefit, close to a 50% decrease in the risk of relapse.”

Per The Washington Post, the U.S. Food and Drug Administration requires more testing with positive results before the drug combination can be approved for public use. The companies hope to start Phase 3 trials later this year.