Merck and Moderna reported on Wednesday that a study involving a personalized mRNA vaccine in combination with the immunotherapy drug Keytruda demonstrated a reduction in skin cancer recurrence and spread compared to using Keytruda alone. This marks the first successful late-stage trial outcome for an mRNA cancer vaccine.
Though the trial is ongoing, interim findings indicate that the treatment, known as Intismeran, achieved its primary objective of lowering cancer recurrence and its secondary aim of preventing cancer spread to other body parts. Dr. Lennard Lee, a consultant medical oncologist and associate professor at Oxford, described these results as “significant,” highlighting that this represents the first positive Phase 3 trial combining immunotherapy and mRNA technology.
Lee emphasized that while this development is noteworthy, crucial details such as the extent of the Phase III benefit, subgroup analyses, quality-of-life data, and overall survival outcomes are yet to be disclosed. Obtaining this information is vital for the scientific and clinical community to fully comprehend the treatment’s impact, patient suitability, and its potential placement within melanoma care practices.
Merck and Moderna plan to present their findings at an upcoming medical conference and submit them to regulatory bodies for evaluation. Melanoma Canada CEO Falyn Katz also expressed optimism about the personalized mRNA therapy, stating that it could provide a potent preventive measure against melanoma recurrence or metastasis for high-risk patients.
The treatment involves combining Merck’s Keytruda with a customized mRNA vaccine from Moderna tailored to the specific mutations present in patients’ tumors. Messenger RNA vaccines, prominently utilized during the COVID-19 pandemic, instruct our cells to assist the immune system in combating pathogens. In this scenario, tumor samples are used to identify abnormal proteins (neoantigens) in cancer cells, allowing the mRNA vaccine to educate the immune system on recognizing and attacking cancer cells harboring these antigens.
The trial enrolled 1,137 high-risk patients with Stage 2B-4 melanoma who had undergone surgical removal. 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 noted no new safety concerns emerged during the trial.
In January, the companies unveiled the results of a mid-stage trial showcasing a 49% reduction in the risk of recurrence or death after five years with the treatment. Following this news, Moderna’s stock surged by over 150% in mid-morning trading, while Merck observed a more than 10% increase.
Melanoma remains a significant concern in Canada, with an estimated 11,300 new diagnoses and 1,250 deaths anticipated this year. Melanoma Canada highlights that this type of cancer is prevalent among Canadians aged 15 to 29 and 30 to 49. In the U.S., over 1.5 million individuals were living with melanoma in 2023, according to the National Cancer Institute.