A new personalized vaccine, developed by Moderna and Merck, has shown potential in a late-stage trial to reduce the risk of high-risk melanoma returning by 49 percent when used in conjunction with the immunotherapy drug Keytruda. The experimental treatment targets patients who have undergone surgery for the deadliest form of skin cancer.
Data from the final-stage trial suggests the combination therapy not only extends the time patients remain cancer-free but also reduces the likelihood of the disease spreading to other parts of the body, compared to Keytruda alone. While a detailed analysis of the results is forthcoming, Moderna's chief executive Stéphane Bancel described the findings as a "pivotal moment for the field of cancer research," highlighting the advancement of mRNA technology for individual cancer treatments.
The jab, named Intismeran, utilizes mRNA technology, similar to that employed in COVID-19 vaccines. However, unlike preventative vaccines, this treatment is tailored to each patient. It involves analyzing tumor samples to identify specific cancer cell mutations, which are then encoded into mRNA. Once administered, this engineered mRNA instructs the patient's immune system to recognize and attack any remaining tumor cells.
Melanoma affects more than 20,000 people annually in the UK, with projections indicating a significant increase in diagnoses by 2040. The disease is particularly lethal at stage 4, when it has already metastasized, with half of patients dying within a year. The latest trial involved over 1,000 patients with advanced melanoma.
Earlier phase 2 trials had also indicated a 49 percent reduction in the risk of melanoma recurrence or death when using the drug combination. Side effects reported from the vaccine include fatigue, injection site pain, and chills.
Moderna and Merck are also exploring similar personalized vaccine approaches for other cancers, including bladder cancer, kidney cancer, and non-small cell lung cancer. If regulatory approval is secured, the companies hope the treatment could be available to patients as early as next year. Questions remain regarding the full extent of the benefit, side effects, and the manufacturing challenges associated with producing personalized doses at scale.
Experts have described the findings as "significant." Dr. Lennard Lee of the University of Oxford noted its importance as the first positive Phase III trial for an individualized neoantigen therapy and an mRNA-based cancer treatment. He emphasized the need to review the complete data, including subgroup analyses and survival results, to fully understand the treatment's benefits and its potential role in routine melanoma care.