Pharmaceutical companies Merck and Moderna announced Wednesday that a late-stage clinical trial for a personalized mRNA-based cancer vaccine successfully prevented melanoma from returning or spreading in high-risk patients. The study tested the vaccine, known as intismeran, in combination with Merck’s immunotherapy drug Keytruda. The companies reported that the combination met its primary goal of extending recurrence-free survival and its secondary goal of preventing the cancer from spreading to other organs.
The trial involved 1,137 patients who had previously undergone surgical removal of their melanomas. Participants were randomized to receive either the vaccine-Keytruda combination or Keytruda alone for approximately one year. While the companies described the results as "clinically meaningful," specific data regarding the duration of survival without recurrence were not released. Full details are scheduled to be presented at a medical conference later this year.
Intismeran is a personalized therapeutic designed to activate an anti-tumor immune response based on the specific mutational signature of an individual patient's tumor. To create the vaccine, manufacturers use a patient's tumor sample to identify mutations, which are then encoded into mRNA. Moderna CEO Stéphane Bancel stated that the technology uses information from a patient’s own cancer to train the immune system to fight it.
Following the announcement, Moderna's stock rose 145 percent to $154.48 in morning trading, while Merck's shares increased 10.6 percent to $149.52. Dean Li, president of Merck Research Laboratories, indicated that the companies intend to begin discussions with federal regulators in the coming months regarding potential approval. An earlier Phase 2 study of the treatment showed a 49 percent reduction in the risk of melanoma recurrence or death compared to using Keytruda alone.
The scale of the reported impact is significant for both the healthcare market and the companies involved. Moderna, which has been seeking to diversify its products beyond COVID-19 vaccines, saw its market value surge by over $91 per share following the news. If federal regulators approve the treatment, it would establish a precedent for personalized mRNA medicine in oncology, moving the technology from an aspirational concept to a commercialized reality for high-risk cancer survivors.
The concrete change for a patient would be a treatment plan tailored specifically to their tumor's genetic code, administered over roughly one year following surgery. This could potentially extend the period they remain disease-free, as most recurrences happen within two to three years of initial treatment. Moving forward, the companies will present their unpublished data to regulators and the medical community later this year, with a formal filing for approval expected to follow in the coming months.