Moderna/Merck—first out of the gate with a personal neoantigen cancer vaccine—who else is in the race and what strategy(ies) will win?

Moderna/Merck are expected to present their data at this 2026 European Society for Medical Oncology (ESMO) Congress demonstrating that the combination of a personal neoantigen cancer vaccine, prepared as a messenger RNA (mRNA) in lipid nanoparticle (LNP) format, and standard-of-care anti-programmed cell death protein 1 (PD-1) antibody (pembrolizumab) is more effective than anti-PD-1 alone in the adjuvant setting of stage IIB-IV melanoma. This is a big win for the up-again, down-again field of cancer vaccines, a field in which past phase III trials have only led to disappointment.