Cancer Vaccine Data: Trial Shows 42% Lower Risk

Researchers have long sought a way to tailor treatments to the unique genetic makeup of an individual tumor. This week, a new study suggests that approach might be getting closer to reality for skin cancer patients. The goal is to create a custom defense against a disease that behaves differently in every patient, a challenge that standard treatments often struggle to meet. This specific trial focused on melanoma, which is the most dangerous type of skin cancer, and looked at whether a vaccine could help keep it from returning after surgery.

The study results, announced by Moderna and Merck, show that a personalized vaccine reduced the risk of death or cancer recurrence by 42% when used alongside a standard treatment. This comparison was made against patients who received only the standard care. The standard treatment used in the trial was an established monoclonal antibody cancer treatment called Keytruda, which is manufactured by Merck. This combination approach is what yielded the significant reduction in risk compared to using the standard drug alone.

The trial involved 1,137 patients who had undergone surgery for stage IIB through IV melanoma before joining the study. Participants were randomly assigned to receive either the personalized vaccine combined with Keytruda, or Keytruda by itself. The assignment was done in a two-to-one ratio, meaning twice as many people received the combination therapy as received the single drug. The goal was to see if adding the vaccine provided a measurable benefit over the established standard of care.

The companies initially announced in August that the trial had succeeded, but they did not release specific figures at that time. They planned to provide details at the European Society of Medical Oncology conference in Madrid. However, the top-line results were released early after an oncology news website reported the data before the scheduled presentation. The full data set for this study has been accepted for publication in the New England Journal of Medicine.

Moderna CEO Stéphane Bancel stated that from the beginning, the company believed mRNA technology could make it possible to develop cancer treatments uniquely matched to each patient's tumor. He called the trial results a defining moment for that vision. The companies are now engaging with regulatory authorities to pursue approval for the vaccine. The broader hope is that this success will help establish mRNA vaccines and individualized cancer-targeting medicines as a new paradigm for treating cancer.