mRNA-Based Vaccine Plus Keytruda Reduces the Risk of Melanoma Spread

Adding an experimental mRNA-based vaccine developed by Moderna and Merck & Co to Keytruda reduced the risk that melanoma would spread by 65 percent over treatment with the immunotherapy drug alone, according to a midstage trial. The results follow earlier promising data from the trial showing the customized mRNA vaccine given in combination with Keytruda cut the risk of death or recurrence of melanoma by 44 percent compared with Keytruda alone.

The Merck/Moderna collaboration is one of several combining powerful drugs that unleash the immune system to target cancers with mRNA vaccine technology. Pfizer’s COVID vaccine partner BioNTech SE and Gritstone Bio are taking similar approaches using mRNA technology. The vaccines all target neoantigens, new mutations that are only present on tumors. Aiming at these unique proteins allows the immune system to kill cancer cells while leaving healthy tissue unscathed.

The key is determining which of many mutations is driving the cancer. To accomplish this, tumors are removed and their genetic makeup is mapped using next-generation DNA sequencing. Artificial intelligence predicts which mutations will be the most effective targets, which are used to build an individualized vaccine targeting only mutations in the patient’s tumor. During this process, patients typically receive an immunotherapy such as Keytruda, which blocks a mechanism cancer uses to hide from the immune system.