LAUSR

It is uncertain if different immunomodulatory drugs (IMID) pose distinct thrombotic risk in patients with newly diagnosed multiple myeloma (MM). Among 2397 MM patients from the SEER-Medicare database from 2007 to 2013, 78% received lenalidomide, and 22% received thalidomide. After inverse probability weighting to balance confounders, the 12-month incidences of venous thromboembolism (VTE 10%) and arterial thromboembolism (ATE 5%) were similarly high in both groups. Lenalidomide versus thalidomide had a subdistribution hazard ratio of 1.11 (0.59–2.02) for VTE and a subdistribution hazard ratio of 0.96 (0.45–1.98) for ATE. Overall survival was not significantly different with a hazard ratio of 0.88 (0.60–1.18) for lenalidomide versus thalidomide. Concurrent anticoagulant prophylaxis was infrequently prescribed in < 20% of both groups. Our study demonstrates that despite improvement in myeloma-directed therapy and supportive care, thrombosis remains an important consideration for all IMID-treated MM patients. Appropriate risk stratification and vigilant thromboprophylaxis remain essential to prevent this complication.