Can an Immune Checkpoint Inhibitor (Sometimes) Make Things Worse?

Champiat and colleagues suggest that a small subset of patients at their center treated with PD1/PDL1 inhibitors appear to exhibit hyperprogression of disease. This commentary goes over some limitations in their preliminary analysis, a possible mechanism to explain the phenomenon, and a means by which other investigators can attempt to validate and further characterize these results. Clin Cancer Res; 23(8); 1879-81. ©2017 AACR See related article by Champiat et al., p. 1920 .