Merck and Moderna announced on Wednesday that a study revealed a personalized mRNA vaccine, when combined with the immunotherapy drug Keytruda, showed a reduction in skin cancer recurrence and spread compared to Keytruda used alone. This marks the first positive late-stage trial outcome for an mRNA cancer vaccine.
The trial is still ongoing, but interim findings indicated that the treatment, named Intismeran, successfully achieved both its primary objective of decreasing cancer recurrence and its secondary goal of preventing cancer spread to other parts of the body.
Dr. Lennard Lee, a consultant medical oncologist and associate professor at Oxford, hailed the results as “significant” and emphasized that it is the first successful Phase 3 trial combining immunotherapy with mRNA technology. Lee highlighted the milestone achievement of having mRNA vaccines developed for cancer treatment within six years of the pandemic.
However, Lee pointed out that crucial details, such as the magnitude of the Phase III benefit, subgroup analyses, quality-of-life data, and overall survival outcomes, are still awaited. These details are essential for the scientific and clinical community to determine the treatment’s efficacy, patient preferences, and its place in melanoma care practices.
Both companies disclosed their intention to present the results at an upcoming medical conference and submit them to regulatory authorities. Melanoma Canada CEO Falyn Katz also expressed optimism about the results, stating that the personalized mRNA therapy could provide a robust preventive measure against melanoma recurrence and metastasis for high-risk patients.
The groundbreaking treatment combines Merck’s Keytruda with a tailored mRNA vaccine from Moderna, designed based on an analysis of mutations present in individual patients’ tumors. mRNA vaccines, known for their role during the COVID-19 pandemic, instruct our cells to bolster the immune system’s response against pathogens. In this approach, tumor samples are utilized to identify abnormal proteins (neoantigens) in cancer cells, which enables the mRNA vaccine to train the immune system to recognize and attack 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 tumors. Participants were randomly assigned to receive up to nine doses of Keytruda alongside the personalized vaccine or Keytruda alone for approximately one year. The companies reported no new safety concerns arising from the trial.
Earlier in January, the companies had released findings from a mid-stage trial demonstrating a 49% reduction in the risk of recurrence or death after five years with this treatment. This positive news led to a surge in Moderna’s shares by over 150% in mid-morning trading, while Merck’s shares also rose by more than 10%.
Melanoma remains a significant health concern in Canada, with an estimated 11,300 new cases expected this year, leading to around 1,250 deaths. Melanoma Canada highlights that this cancer type is prevalent among Canadians aged 15 to 49. In the U.S., more than 1.5 million individuals were living with melanoma in 2023, as reported by the U.S. National Cancer Institute.