Garon EB, Aerts J, Kim JS, et al. - Researchers examined the safety of pemetrexed and platinum in combination with pembrolizumab in this post hoc analysis, focusing on time-to-onset and time-to-resolution of all-cause any-grade and grade ≥ 3 adverse events (AEs) and renal AEs. In the all-subjects-as-treated population (pembrolizumab arm, n = 405; placebo arm, n = 202), as well as in cases managed with ≥ 5 cycles of pemetrexed (pemetrexed/ pembrolizumab/platinum arm, n = 310; pemetrexed/placebo/platinum arm, n = 135), patient-level data from KEYNOTE-189 were assessed. In both treatment arms, a median time-to-onset for most non-hematologic and hematologic grade ≥ 3 AEs with ≥ 2% incidence was within the first 4 cycles; median time-to-resolution was within 2 weeks from onset. Findings demonstrated manageable toxicity of pemetrexed/pembrolizumab/platinum with longer duration of treatment. In the pembrolizumab combination vs pemetrexed, a slightly higher incidence of renal toxicity was observed, though there was no elevation in the incidence in later treatment cycles. The safe use of the KEYNOTE-189 regimen in clinical practice is thus supported by the findings.