Merck and Moderna announced on Wednesday that a study unveiled promising results for a tailored mRNA vaccine in combination with the immunotherapy drug Keytruda, showing a decrease in skin cancer recurrence and spread compared to using Keytruda alone. This marks a significant advancement as it is the first successful late-stage trial outcome for an mRNA cancer vaccine.
While the trial is still ongoing, interim findings indicated that the treatment, named Intismeran, achieved its primary objective of reducing cancer recurrence and its secondary goal of preventing cancer from spreading to other parts of the body. Dr. Lennard Lee, a consultant medical oncologist and associate professor at Oxford, emphasized the significance of these results, highlighting that this is the first positive Phase 3 trial combining immunotherapy with mRNA technology.
Lee acknowledged the importance of the findings but noted that critical details, such as the magnitude of the Phase III benefit and subgroup analyses, are yet to be disclosed. These forthcoming data will be crucial for the scientific and clinical communities to gauge the treatment’s efficacy, patient suitability, and potential integration into standard melanoma care.
Both companies affirmed their intention to present the results at an upcoming medical conference and provide them to regulatory bodies for review. Melanoma Canada CEO Falyn Katz praised the outcomes, emphasizing the potential of this personalized mRNA therapy to offer a new approach to preventing melanoma recurrence and metastasis in high-risk patients.
The combination treatment involves Merck’s Keytruda with a customized mRNA vaccine from Moderna, tailored based on the mutations identified in the patients’ tumor samples. mRNA vaccines, notable for their role during the COVID-19 pandemic, instruct cells to help the immune system combat pathogens. In this case, the mRNA vaccine targets abnormal proteins in cancer cells known as neoantigens, training the immune system to identify and eliminate cancer cells carrying these antigens.
The trial enrolled 1,137 high-risk patients with Stage 2B-4 melanoma who had undergone surgical removal of the tumor. Participants were randomly assigned to receive up to nine doses of Keytruda along with the personalized vaccine or Keytruda alone for approximately one year. The companies reported no new safety concerns arising from the trial.
Earlier this year, the companies shared the results of a mid-stage trial demonstrating a 49% reduction in the risk of cancer recurrence or mortality after five years. Market response to these developments was positive, with Moderna’s stock surging more than 150% in mid-morning trading and Merck’s climbing over 10%.
Melanoma remains a significant health concern, with an estimated 11,300 new cases expected in Canada this year, resulting in approximately 1,250 deaths. Melanoma Canada highlights that melanoma is prevalent among Canadians aged 15 to 49. In the U.S., the National Cancer Institute reported over 1.5 million individuals living with melanoma in 2023.