Personalized cancer neoantigen vaccines show success in two small studies

Two papers published Wednesday in the journal Nature showed promise for personalized cancer vaccines, which work by stimulating the immune system to attack cancer cells.

In one study lead by Catherine Wu, MD, of the Dana-Farber Cancer Institute, four out of six melanoma patients remain cancer-free after two years of treatment with vaccines that target proteins unique to their tumors. Two other patients who relapsed then received an anti-PD-1 checkpoint inhibitor and saw their tumors shrink.

In the other paper, eight of 13 melanoma patients remained cancer-free after a year of receiving RNA-based cancer vaccines. That study was led by Ugur Sahin, MD, a professor at the University of Mainz, Germany, and CEO of neoantigen biotech firm BioNTech.

The results from Dana-Farber and BioNTech – both of which are participating in the Parker Institute for Cancer Immunotherapy’s Tumor Neoantigen Selection Alliance – are some of the first published clinical trial data about cancer neoantigen vaccines in humans.

While the studies were small, the promising results point to cancer vaccines becoming another weapon in the immunotherapy arsenal to treat tumors, said Fred Ramsdell, PhD, vice president of research at the Parker Institute for Cancer Immunotherapy.

“Neoantigens and the vaccines that target them are likely to be an important tool in the fight against cancer,” Ramsdell said. “These investigators have used new tools and understanding to re-examine the concept of cancer vaccines in the context of modern immunotherapy, including checkpoint blockade. The results are both significant for the individual patients involved, and also for the field as a whole.”

Neoantigens are pieces of proteins found largely on the surface of tumor cells. Many of them are unique to a patient, or even a tumor, making them ideal candidates to use as targets for therapy that is tailored to a patient, ideally causing fewer side effects. They arise from mutations in tumor DNA, which means they can be mathematically predicted from patient samples using computer algorithms.

One of the major challenges in creating cancer vaccines is making accurate neoantigen predictions – ones that tell scientists which mutations will result in neoantigens that will be recognized by and stimulate the immune system so that it can find and kill the cancer cells in question.

The first phase of the Parker Institute’s neoantigen alliance launched with the Cancer Research Institute in December and is focused on establishing the best way to accurately predict neoantigens. The end goal is creating effective cancer vaccines tailored to a patient’s tumor.

The alliance is a collaboration of more than 35 partners from industry and academia.

Read more about the Parker Institute’s Tumor Neoantigen Selection Alliance