Thromboembolic events in patients with advanced non-small cell lung cancer receiving palliative chemoimmunotherapy with pembrolizumab.

Abstract

e24068 Background: Thromboembolic events (TEEs) represent a serious and clinically significant complication in patients (pts) with cancer undergoing systemic treatment. The incidence of TEEs in pts with non–small cell lung cancer (NSCLC) receiving palliative chemotherapy has been reported to range from 6 to 30%. However, data on the incidence and characteristics of TEEs associated with palliative chemoimmunotherapy remain limited. Methods: In this retrospective, single-center study, we analyzed TEEs in 192 pts with NSCLC who initiated palliative pembrolizumab-based chemoimmunotherapy between January 2019 and August 2024. Treatment regimens consisted of pembrolizumab combined with pemetrexed and platinum (n=128) or paclitaxel and carboplatin (n=64). TEEs occurring during chemoimmunotherapy or within six months after treatment discontinuation were included, while events following a change of regimen were excluded. Results: TEEs occurred in 27 patients (14%, pemetrexed: 21, paclitaxel: 6), including two fatal events, both of which were myocardial infarctions. Pulmonary thromboembolism was the most common TEE (n=9), followed by deep vein thrombosis (n=7). TEEs occurred at a median of 106 days (range, 3–838 days) after initiation of chemoimmunotherapy. No significant factors, including the Khorana score and regimens, were identified to be associated with the occurrence of TEEs. Conclusions: In real-world practice, the incidence of TEEs in pts with NSCLC receiving palliative pembrolizumab-based chemoimmunotherapy was higher than that reported in phase III trials. Therefore, careful surveillance for TEEs during chemoimmunotherapy, with consideration of anticoagulation in high-risk pts, may be warranted.