Promising Phase III Melanoma Results Build on Research Conducted at Georgetown Lombardi

Posted in Lombardi Stories  |  Tagged clinical trials, melanoma, mRNA vaccine, research

(August 19, 2026) — A promising new approach to preventing high-risk melanoma from recurring after surgery has yielded positive results in a large clinical trial, building on earlier research that included investigators and patients at Georgetown University’s Lombardi Comprehensive Cancer Center.

Merck and Moderna announced Aug. 19 that the trial of a personalized mRNA-based cancer therapy, intismeran autogene, given in combination with the immunotherapy pembrolizumab (Keytruda), significantly reduced the risk of the cancer returning or patients dying compared with pembrolizumab alone.

The international Phase III trial enrolled 1,137 patients with high-risk melanoma that had been completely removed by surgery. According to the companies, the combination produced a statistically significant and clinically meaningful improvement compared with pembrolizumab alone. Detailed results are expected to be presented at an upcoming medical meeting.

The findings build on years of research, including the Phase II KEYNOTE-942 clinical trial, in which Georgetown Lombardi was among the participating cancer centers. The study included 157 patients in the United States and Australia and helped provide the evidence for advancing the approach to the larger Phase III trial.

“The KEYNOTE-942 trial showed that the combination of intismeran plus pembrolizumab produced at 49% reduction in the risk of melanoma relapse compared to pembrolizumab alone,” said Michael Atkins, MD, deputy director of Georgetown Lombardi and an internationally recognized expert in melanoma and cancer immunotherapy. Atkins treats patients at MedStar Georgetown University Hospital.

“If this benefit was reproduced in the recently reported Phase III trial, then approximately half the patients anticipated to relapse with pembrolizumab alone will be spared relapse with the addition of the personalized mRNA vaccine,” he said. “This would be a clinically meaningful result which could become the new standard of care for the treatment of patients with high-risk surgically removed melanoma and has implications for the adjuvant treatment of several other cancer types.”

Unlike vaccines designed to prevent infectious diseases, the investigational therapy in the study is created individually for each patient. Researchers analyze a patient’s tumor for genetic mutations and use that information to develop an mRNA therapy designed to help the immune system recognize and attack cancer cells unique to that patient.

For patients who participate in clinical trials, the impact of their contribution can extend well beyond their own care.

Angela Evatt, who was diagnosed with an advanced stage (IIIC) melanoma in 2020, was among the people who participated in the earlier Phase II trial through Georgetown Lombardi and MedStar Health. Her participation, and that of patients at research centers around the world, helped investigators determine whether the approach warranted testing in a much larger population.

“I was very excited to hear that the clinical trial results continue to show promise,” said Evatt. “With each release of the study results, it continues to give me hope that there is less of a likelihood of recurrence for me and others. The scientists and care providers deserve the recognition, because it’s the culmination of their work in immunotherapy that has made this possible.”

The new results underscore the role of comprehensive cancer centers like Georgetown Lombardi in advancing discoveries from early research toward new treatments, bringing together investigators, clinical expertise, research infrastructure and, critically, patients. Clinical trials are a vital part of that work, bringing leading-edge research and potential new treatments closer to home for patients and families.

“I have been disease-free for over five years now and enjoy life to the fullest, with travel and treasured moments with family and friends. The diagnosis never goes away, but I am grateful to the Lombardi team for their work and continued care,” Evatt said.

According to Merck and Moderna, the Phase III study will continue to evaluate additional outcomes, including overall survival. The therapy remains investigational and has not been approved by the U.S. Food and Drug Administration.