The Open-Source Toolkit That's Putting Personalized Cancer Vaccines Within Reach
In June 2026, a 62-year-old melanoma patient who had already failed two lines of therapy received an experimental vaccine. It wasn’t an off-the-shelf drug. It was built from the DNA of their own tumor, encoding 34 custom neoantigens selected by an algorithm trained on thousands of other patients’ cancers. Six months later, scans showed no new lesions.
That vaccine, Moderna’s mRNA-4157 (now called V940), is the most visible example of a quiet revolution in the open-source code repositories where computational biologists build the tools that make personalized cancer immunotherapy possible. One of those tools, pVACtools, just got its biggest update yet.