Moderna and Merck & Co – known as MSD outside the US and Canada – have shared promising three-year data for their investigational skin cancer vaccine mRNA-4157 (V940).

The phase 2b KEYNOTE-942/mRNA-4157-P201 study has been evaluating the candidate in combination with Merck’s anti-PD-1 therapy Keytruda (pembrolizumab) in 157 patients with high-risk stage 3 or 4 melanoma, following complete resection.

The results presented at this year’s American Society of Clinical Oncology Annual Meeting showed that after a median follow-up of 34.9 months, adjuvant treatment with mRNA-4157 plus Keytruda continued to demonstrate a clinically meaningful and durable improvement in the trial’s primary endpoint of recurrence-free survival (RFS), reducing the risk of recurrence or death by 49% compared to Keytruda alone.

The combination also continued to demonstrate a meaningful improvement in distant metastasis-free survival (DMFS), a key secondary endpoint of the study, compared to Keytruda alone, reducing the risk of developing distant metastasis or death by 62%.

The incidence of melanoma, a type of skin cancer that develops when pigment-producing cells located in the skin grow uncontrollably, has been rising over the past few decades, with more than 330,000 new cases diagnosed globally in 2022.

In the US, where skin cancer is one of the most common types of cancers diagnosed, it is estimated there will be more than 100,000 new cases of melanoma this year.

mRNA-4157, an individualised neoantigen therapy, is designed to stimulate an immune response by generating specific T-cell responses based on the unique mutational signature of a patient’s tumour, while Keytruda increases the ability of the body’s immune system to help detect and fight tumour cells.

Commenting on the latest results for the combination, Kyle Holen, Moderna’s senior vice president and head of development, therapeutics and oncology, said: “This data highlights the sustained benefit in RFS and DMFS of mRNA-4157 as adjuvant treatment in combination with Keytruda in people with resected high-risk melanoma.”