Merck and Moderna announced on Wednesday that a study involving a customized mRNA vaccine in combination with the immunotherapy drug Keytruda has shown a decrease in skin cancer recurrence and spread compared to using Keytruda alone. This marks the first positive late-stage trial outcome for an mRNA cancer vaccine.
The trial, named Intismeran, is still ongoing, but interim results have indicated that the treatment has successfully achieved its primary goal of reducing cancer recurrence and its secondary goal of preventing the spread of cancer to other body parts. Dr. Lennard Lee, a consultant medical oncologist and associate professor at Oxford, described the findings as “significant,” highlighting that this is the first successful Phase 3 trial of a treatment combining immunotherapy and mRNA technology.
Lee emphasized that crucial information is still pending release, including the extent of the Phase III benefit, detailed subgroup analyses, quality-of-life data, and overall-survival results. These details are essential for the scientific and clinical community to understand the treatment’s magnitude, the most responsive patients, and its potential placement in melanoma care protocols.
Both companies have stated their intention to present the results at an upcoming medical conference and share them with regulatory bodies. Melanoma Canada CEO Falyn Katz expressed optimism about the results, emphasizing the potential of personalized mRNA therapy to provide a new, effective approach for preventing melanoma recurrence and metastasis in high-risk patients.
The treatment combines Merck’s Keytruda with a customized mRNA vaccine from Moderna tailored to match mutations found in individual patients’ tumors. mRNA vaccines, known for their role in the COVID-19 pandemic, instruct cells to help the immune system combat pathogens. In this treatment, tumor samples are utilized to identify abnormal proteins known as neoantigens in cancer cells, which the mRNA vaccine trains the immune system to recognize and target.
The trial involved 1,137 high-risk patients with Stage 2B-4 melanoma who had undergone surgical tumor removal. Participants were randomly assigned to receive either up to nine doses of Keytruda plus the personalized vaccine or Keytruda alone for approximately a year. The companies reported no new safety concerns arising from the trial.
Earlier in January, the companies had disclosed the results of a mid-stage trial demonstrating a 49% reduction in the risk of recurrence or death after five years with this treatment. Following the announcement, Moderna’s stock surged by over 150%, while Merck’s stock also saw a rise of more than 10%.
Melanoma remains a significant health concern, with an estimated 11,300 new cases expected in Canada this year, leading to an estimated 1,250 deaths. Melanoma Canada highlights that melanoma is prevalent among Canadians aged 15 to 49. In the U.S., there were over 1.5 million individuals living with melanoma in 2023, according to the U.S. National Cancer Institute.
