Comparison of pembrolizumab dosing regimens and incidence and severity of immune-related adverse effects: A retrospective, case-control study

The comparison of the 21-day and 42-day pembrolizumab dosing cohorts revealed similar irAE rates and severity of toxicities. Rates of steroid initiation for irAE management and permanent treatment discontinuation due to irAE did not significantly differ between dosing schedules. While severe irAEs correlated with treatment discontinuation, dosing schedule did not differentially affect this outcome. Overall, extending the pembrolizumab dosing interval to 42 days appears safe while maintaining an irAE profile comparable to that with the standard 21-day schedule.