Precision T-cell therapy targets tumours

The T cells of the immune system can destroy tumours, but their activation can be inefficient. Vaccines that exploit tumour mutations elicit robust T-cell responses to tumours, with potential clinical benefits. See Letters p.217 & p.222 Neoantigens have long been considered optimal targets for anti-tumour vaccines, and recent mutation coding and prediction techniques have aimed to streamline their identification and selection. Two papers in this issue report results from personalized neoantigen vaccine trials in patients with cancer. Catherine Wu and colleagues report the results of a phase I trial of a personalized cancer vaccine that targets up to 20 patient neoantigens. The vaccine was safe and induced tumour-antigen-specific immune responses. Four out of six patients treated showed no recurrence at 25 months, and progressing patients responded to further therapy with checkpoint inhibitor. Ugur Sahin and colleagues report the first-in-human application of a personalized neoantigen vaccine in patients with melanoma. Their vaccination strategy includes sequencing and computational identification of neoantigens from patients, and design and manufacture of a poly-antigen RNA vaccine for treatment. In 13 patients, the vaccine boosted immunity against some of the selected tumour antigens from the individual patients, and two patients showed infiltration of tumour-reactive T cells. These results suggest that personalized vaccines could be refined and tailored to provide clinical benefit as cancer immunotherapies.