Venous thromboembolism events in patients with advanced cancer on immune checkpoint inhibitors

Aim: To evaluate the correlation between venous thromboembolism events (VTEs) and immune checkpoint inhibitor (ICI)-based regimens. Methods: This is a retrospective study of 403 patients with advanced cancer on ICI-based regimens. Results: We report 8% VTE incidence post-ICI initiation over a median of 11.1 months of follow-up. Compared with single-agent ICI, dual-ICI was significantly correlated with higher incidence of VTE (odds ratio [OR]: 4.196, 95% CI: 1.527-11.529, p = 0.005), but chemotherapy-immuno-oncology combination was not (OR: 1.374, 95% CI: 0.285-6.632, p = 0.693). Subsequent systemic therapy post-ICI was also independently associated with higher VTE incidence (OR: 2.599, 95% CI: 1.169-5.777, p = 0.019). Conclusion: Our findings suggest potential underreporting of VTE incidence in ICI clinical trials. As dual-ICI is becoming more prevalent in cancer management, clinicians should maintain vigilance regarding VTE in patients with advanced cancer on ICI-based regimens.