Chronotherapy with immune checkpoint inhibitors: The knowns, the unknowns, and the contested.

Emerging data indicate that immune checkpoint inhibitors can exhibit time-of-day-dependent effects in pre-clinical models. Furthermore, multiple retrospective clinical trials associate earlier anti-tumor treatment timing with improved outcomes. However, key questions remain regarding the reproducibility of these findings, the underlying mechanisms, and their clinical implications. This commentary discusses these open questions and provides an outlook on the field.