Pharmacologic Anticoagulation Is Associated With a Lower Risk of Recurrent Venous Thromboembolic Events During Janus Kinase Inhibitor Use for Patients With a Prior Thrombosis.

BACKGROUND:Janus kinase (JAK) inhibitors tofacitinib and upadacitinib are effective therapies for inflammatory bowel disease and rheumatologic disorders but currently possess a warning for increased venous thromboembolism (VTE) risk. Some patients with a history of VTE may benefit from a JAK inhibitor, but the risk of recurrent VTE with JAK inhibitor use is unclear. Our goal was to observe rates of new VTE events after starting JAK inhibitor therapy in patients with a prior VTE, and observe whether concurrent anticoagulation (AC) reduces this risk. METHODS:We conducted a review of adults prescribed tofacitinib or upadacitinib between January 1, 2000, and June 30, 2023, with a prior history of VTE. Patient charts were reviewed for demographic data, disease type, and VTE date(s), and to verify duration of JAK inhibitor use along with any concurrent AC. VTEs following JAK inhibitor initiation were identified by International Classification of Diseases-Tenth Revision code and verified by physician documentation and imaging. RESULTS:We identified 79 patients with a documented VTE history before initiating JAK inhibitors, 47 of whom began a JAK inhibitor with concurrent AC. Of these, 15 patients discontinued AC while receiving JAK inhibitors. In total, 5 new VTE events were observed during 55.42 patient-years of JAK inhibitor treatment without concurrent AC (9.0 events per 100 patient-years), while no new VTE events occurred during 65.2 patient-years of JAK inhibitor treatment with concurrent AC, demonstrating a lower risk of recurrent VTE (P = .020). CONCLUSIONS:These results suggest that for patients with a prior VTE history there is a high risk for recurrent VTE while receiving JAK inhibitors. Concurrent use of AC with JAK inhibitors appears to be protective against recurrent VTEs in this population.