BioCentury
ARTICLE | Translation in Brief

From MSI-high to MSI-higher

Setting a higher bar for the first tissue-agnostic biomarker

May 2, 2019 6:03 PM UTC

A study in Science offers more clues to the consistent but poorly defined link between tumor mutation load and checkpoint inhibitor response. The data could explain why less than half of patients with MSI-high status benefit from anti-PD1 mAbs, and provides more evidence that frameshift mutations are the dominant neoantigens driving antitumor immunity.

High tumor mutation burden (TMB) has repeatedly been associated with checkpoint inhibitor responses in retrospective clinical studies, but the metric is not entirely predictive, and how to define TMB high status remains unclear (see “TMB Needs Company”). ...