The Washington PostDemocracy Dies in Darkness

Experimental skin cancer vaccine shows promising early results

The effort is the first to show that a cancer vaccine using messenger RNA may be effective

The experimental cancer therapy combined a vaccine created by Moderna using mRNA technology with Merck’s immunotherapy drug, marketed as Keytruda. (Dado Ruvic/Reuters)

For the first time, messenger RNA technology — the advance that undergirds the most commonly used coronavirus vaccines — has been shown effective against a deadly form of skin cancer, when used in conjunction with a second cancer drug, according to preliminary study results released Tuesday.

The experimental cancer vaccine from Moderna that uses mRNA, combined with Merck’s cancer immunotherapy drug pembrolizumab, marketed as Keytruda, performed well in mid-stage testing in patients battling melanoma, the two companies announced Tuesday.

After surgery and as long as a year on the pair of drugs, melanoma patients in the trial saw a 44 percent reduced risk of recurrence or death compared with patients who received Keytruda alone, according to the announcement. The companies did not release the results of the study itself, which have not yet been independently reviewed.

“Today’s results are highly encouraging for the field of cancer treatment,” Stéphane Bancel, Moderna’s chief executive, said in a news release. “mRNA has been transformative for COVID-19, and now, for the first time ever, we have demonstrated the potential for mRNA to have an impact on outcomes in a randomized clinical trial in melanoma.”

Bancel said the full data from the melanoma study will be shared with health authorities, including the Food and Drug Administration, and released at a medical conference. The Phase 2b trial involved 157 patients with Stage 3 or 4 melanoma that had spread to a lymph node and who faced a high risk of recurrence. The patients were split randomly into two groups.

Positive results in a larger Phase 3 trial are required before the FDA will consider allowing the drug combination on the market. The companies said they hope to begin that trial next year.

In addition to using the breakthrough mRNA technology, Moderna’s proposed vaccine employs a “personalized” approach designed to prompt a patient’s immune system to attack the specific mutations of his or her tumors.

Francis S. Collins, former director of the National Institutes of Health, said in an interview with Washington Post Live last week that development of vaccines for cancer using mRNA technology may be one of the great medical advances to come out of the pandemic. “Cancer vaccines have had a lot of promise, but they have been really not quite taking hold because the cycle time was just too long,” he said. “Now with mRNAs, you can do that so much more quickly.”

Jason Luke, director of the Cancer Immunotherapeutics Center at UPMC Hillman Cancer Center in Pittsburgh, agreed that the results, while from a Phase 2 study, signal “a tipping point” in cancer treatment.

The ability to assess a tumor to design a personalized medication, produce it and get it into a patient within a matter of weeks is where “genomics meets computational biology meets immunology meets my patient in my clinic,” he said.

“It really sounds like science fiction. But I really do think that’s the world we’re moving into.”

Dozens of clinical trials are testing mRNA treatment vaccines in people with various types of cancer, including pancreatic cancer and colorectal cancer in addition to melanoma — some also in combination with drugs that enhance the body’s immune response. But no mRNA cancer vaccine has yet been approved by the FDA.

Merck’s drug Keytruda is a monoclonal antibody that helps the immune system fight invading cancers by removing barriers that inhibit its efforts.

“Serious adverse events” related to the Moderna and Merck treatments occurred in 14.4 percent of patients who received the drug combination and 10 percent of those who received Keytruda alone.

In 2018, the most recent year for which data is available, 83,996 people were diagnosed with melanoma in the United States and 8,199 died of it, according to the Centers for Disease Control and Prevention. The five-year survival rates of the disease are estimated at 60.3 percent for Stage 3 and 16.2 percent for Stage 4, according to the companies.

Frances Stead Sellers contributed to this report.