Global Trial to Investigate Skin Cancer Vaccine/Immunotherapy Combo

Patients with skin cancer can now enroll in a late-stage clinical trial testing a personalized mRNA-based vaccine in combination with the immunotherapy agent, Keytruda (pembrolizumab), according to a joint announcement from Moderna, the manufacturer of the vaccine, and Merck, the manufacturer of Keytruda.

Researchers plan on enrolling more than 1,000 patients with melanoma whose tumors were surgically removed. The main goal of the study — which will be conducted in more than 20 countries — is to determine if vaccine/immunotherapy combination improves the amount of time patients live without their cancer returning, (a statistic known as recurrence-free survival). Outcomes will be compared among two groups: some patients will receive the vaccine plus Keytruda, while others will receive Keytruda alone.

Prior findings from the phase 2b mRNA-4157-P201/KEYNOTE-942 trial demonstrated promise with the vaccine/immunotherapy combination. In fact, giving the two together led to a 44% reduction in the risk of death or recurrence in patients with high-risk, resected melanoma, according to findings presented at the 2023 AACR Annual Meeting.

READ MORE: Cancer Vaccine Combo a ‘Potential Major Breakthrough’ in Skin Cancer

Additionally, data showed that at the 18-month mark, 78.6% of patients were alive and without disease recurrence in the vaccine/Keytruda group, compared with 62.2% in the Keytruda-only group.

The investigational vaccine works similarly to COVID-19 vaccines, in that it is mRNA based. The personalized injection works by promoting the generation of T cells, which are a part of the immune system that fights off foreign invaders, such as cancer.

Keytruda also uses the patient’s immune system by blocking certain proteins on the cancer cell surface that allow the tumors to hide from the immune system. When these proteins are no longer active, T cells can better find and attack the cancer.

This is not the only research regarding cancer vaccines that is currently ongoing. In a January 2023 interview with CURE®, one expert said, “I think that there's concerted efforts, both on the academic side and also on the industry side, to work on (cancer vaccines). … the signals are all in the positive.”

Additionally, phase 1 study data that was published in the journal, Nature, showed that a personalized mRNA-based pancreatic cancer vaccine called autogene cevumeran — when given after surgery and Tecentriq (atezolizumab), and alongside a chemotherapy regimen — was successful in staving off cancer’s return for 18 months in patients who had a strong T-cell response to the vaccine. Of note, Tecentriq is an immune checkpoint inhibitor that works similarly to Keytruda.

The study was small, with only 16 patients being treated with the investigational vaccine, and the researchers mentioned that more trials need to be conducted in this space.

“Here, we provided evidence that despite the low mutation rate of (pancreatic cancer), a mRNA vaccine can induce T cell activity against neoantigens in this cancer, a non-inflamed tumor with predominantly immune-excluded or desert phenotypes,” the researchers wrote in their study. “Whether mRNA neoantigen vaccines can similarly activate T cells in other non-inflamed cancers should be more broadly tested.”

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