Thromboembolic Events Related to Treatment with Checkpoint Inhibitors: Report of Two Cases.

Despite the significant clinical benefits, checkpoint inhibition is associated with a unique spectrum of immune-related adverse events. It is sometimes difficult to distinguish some rare adverse effects from a cancer progression; thus, such effects should be reported in clinical trials to be diagnosed by physicians. Only a few cases of arterial embolic events have been described in studies related to patients treated by immunotherapy. In this article, we report the cases of 2 patients who presented rare and severe thromboembolic events after using checkpoint inhibitors. The first case describes multiple organ embolism at the same time, associated with other autoimmune symptoms. In the second case, distal digital necrosis emerged after the initiation of immunotherapy. There is insufficient data about the real incidence of thromboembolic and rheumatological events related to checkpoint inhibition. Future trials should be done to establish preventive strategies.