mRNA Cancer Vaccine Hopes Become a Reality in a Phase 2 Trial

What are Neoantigen Cancer Vaccines?

It may surprise you to know that the immune system is able to recognize and eliminate many cancerous cells from the body before they develop into tumors. Cancer arises from the cells that the immune system misses, when it is too challenging to differentiate the cancer cells from normal, healthy cells.

However, all cancer cells are heavily mutated, and those mutations will produce unique alterations to proteins expressed by the cancer cell. Using genomic sequencing of an individual patient’s tumor, researchers can identify the exact mutations present and design a vaccine to target the altered parts of the affected proteins, called neoantigens. 

New Data from Merck and Moderna for Cancer Vaccine and Keytruda Combination

In a Phase 2 clinical trial, Merck and Moderna randomly assigned 157 patients with stage 3 or 4 melanoma to receive treatment with only pembrolizumab (Keytruda), a targeted cancer immunotherapy that blocks PD-1, or combination therapy of pembrolizumab and a custom neoantigen vaccine. After 18 months, 78.6% of those who got the combination had no recurrence of their cancer, compared to 62.2% of patients treated with pembrolizumab alone.

This study is a critical proof-of-concept for neoantigen vaccines, as it is still unclear exactly how these vaccines help prime the immune system to better identify and eliminate cancer cells. Suggestions include priming the immune system to recognize novel neoantigens, or helping activate existing T cells. There could even be a phenomenon called “epitope spread,” where the death of cancer cells containing the neoantigens in the vaccine reveals cells with other antigens that the immune system is able to recognize.

The Future of Precision Medicine

Neoantigen vaccines get right to the heart of the goals of precision medicine research, since they can be so highly tailored to an individual patient. Merck and Moderna’s cancer vaccines contained up to 34 neoantigens per patient, creating a nearly unprecedented level of specificity for the patient.

mRNA technology will be an essential part of developing affordable, effective personalized treatments. Expanding from mRNA vaccines against a single viral antigen of SARS-CoV-2 to complex mixtures of 34 neoantigens is a major technological step forward, opening the doors to many other therapeutic applications of mRNA vaccines and treatments. Merck and Moderna are planning a Phase 3 trial for this year that will expand to include additional cancer types.

Outsourcing Bioinformatics Analysis: How Bridge Informatics Can Help

Groundbreaking studies like these are made possible by advances that have made whole genome sequencing, sample processing, and data analysis faster, cheaper, and more accessible than ever before. From pipeline development and software engineering to deploying existing bioinformatics tools, Bridge Informatics can help you on every step of your research journey.
As experts across data types from leading sequencing platforms, we can help you tackle the challenging computational tasks of storing, analyzing and interpreting genomic and transcriptomic data. Bridge Informatics’ bioinformaticians are trained bench biologists, so they understand the biological questions driving your computational analysis. Click here to schedule a free introductory call with a member of our team.

Jane Cook, Biochemist & Content Writer, Bridge Informatics

Jane Cook, leading Content Writer for Bridge Informatics, has written over 100 articles on the latest topics and trends for the bioinformatics community. Jane’s broad and deep interdisciplinary molecular biology experience spans developing biochemistry assays to genomics. Prior to joining Bridge, Jane held research assistant roles in biochemistry research labs across a variety of therapeutic areas. While obtaining her B.A. in Biochemistry from Trinity College in Dublin, Ireland, Jane also studied journalism at New York University’s Arthur L. Carter Journalism Institute. As a native Texan, she embraces any challenge that comes her way. Jane hails from Dallas but returns to Ireland any and every chance she gets. If you’re interested in reaching out, please email or

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