Personalized Cancer Vaccine Shows Promise in Melanoma Treatment
A custom-made mRNA vaccine combined with immunotherapy reduced the risk of recurrence or death by 42% in late-stage melanoma patients over two years.
A personalized cancer vaccine, intisomeran, developed by Moderna and Merck, has demonstrated a significant reduction in the risk of melanoma recurrence or death. In a study involving over 1,130 patients with late-stage melanoma whose tumors were surgically removed, the custom-made vaccine, when given alongside the immunotherapy drug Keytruda, lowered the risk of cancer returning or death by 42% over a two-year period compared to treatment with Keytruda alone.
The study participants were randomly assigned to receive either the intisomeran vaccine along with Keytruda or a placebo vaccine with Keytruda. The intisomeran vaccine is designed to train the immune system to recognize specific proteins found on tumor cells. This approach uses messenger RNA (mRNA) technology, similar to that used in Moderna's COVID-19 vaccines, to encode these proteins. When the immune system encounters these encoded proteins, it identifies them as foreign and mounts an attack.
Keytruda, a checkpoint inhibitor, works by removing natural brakes on the immune system, enabling immune cells to better identify and target cancer cells. The combination therapy aims to enhance the immune system's ability to fight melanoma.
Dr. David Berman, chief development officer at Moderna, noted that the Phase 3 study results closely mirrored those of an earlier Phase 2 study. The prior study, released in June, showed a 49% reduction in the risk of cancer recurrence or death over one year for the combination therapy and a 59% reduction in the risk of cancer spread compared to Keytruda alone. Berman expressed surprise that the Phase 3 study, which included a broader patient population, yielded such similar positive outcomes.
Evidence suggests that the treatment's effect begins to manifest around six months into therapy. Berman explained that this timeframe allows the immune system, particularly T cells critical for cancer detection, sufficient time to activate and learn to recognize tumor cells. This finding could shed light on why only about 30% of cancer patients respond to checkpoint inhibitors. The intisomeran vaccine may play a crucial role in educating the immune system to recognize cancer cells in patients who do not respond to immunotherapy alone.
Data on overall survival for patients receiving the combination therapy is still being collected. Moderna and Merck are exploring the intisomeran-Keytruda pairing in other cancer types, including pancreatic, gastric, and non-small cell lung cancer, through multiple ongoing studies. Early research is also investigating the use of intisomeran as a standalone treatment for lung cancer.
While personalized therapies have historically faced challenges due to high costs and lengthy development times, Berman expressed confidence in the scalability and potential affordability of the mRNA-based vaccine production process. He highlighted the enzymatic nature of the production and the speed at which customized vaccines can be developed, noting that scientists can create a patient-specific vaccine within weeks, a critical factor for individuals battling cancer.