Background  Multiple myeloma (MM) patients have a higher risk of thrombotic events (TEs) when treated with lenalidomide-based regimens. However, there is a discrepancy between current guidelines and clinical practice in thromboprophylaxis and the varied incidence of TEs.

  Objective  To observe the incidence of multiple myeloma related thrombotic events (TEs) in patients treated with lenalidomide-based regimens.

  Methods  From January 2010 to December 2020, a retrospective study was performed in 46 newly diagnosed MM patients who received lenalidomide-based regimens in the Second Medical Center of Chinese PLA General Hospital, and the incidence of TEs was analyzed.

  Results  The mean age of 46 patients (27 males and 19 females) at diagnosis was 60.0 ± 12.7 years, with the median duration of lenalidomide use of 16 (5-90) months. A total of 32 patients (69.6%) received thromboprophylaxis, of which 31 patients received aspirin antiplatelet therapy, and 1 case received rivaroxaban anticoagulant therapy. TEs were observed in 6 cases (13.04%, 6/46), and all of them was deep venous thromboembolism, including 1 case of pulmonary embolism. Upper gastrointestinal bleeding occurred in 1 case. All the patients with bleeding or TEs were treated appropriately in time, and no one died or stop medication.

  Conclusion  MM patients receiving lenalidomide-based regimens have a higher incidence of TEs, so prevention should be strengthened in clinical treatment.