Thrombosis events in Chinese patients with newly diagnosed multiple myeloma

A high risk of thrombosis is seen in patients with newly diagnosed multiple myeloma (NDMM), particularly those treated with immunomodulatory drugs (IMiDs). Large cohorts addressing the thrombosis issue of NDMM patients in Asia are lacking. We retrospectively analyzed the clinical information of NDMM patients diagnosed in Zhongshan Hospital Fudan University, a national medical center, from January 2013 to June 2021. Death and thrombotic events (TEs) were the endpoints. To investigate risk factors for TEs, the Fine and Gray competing risk regression models were created, in which unrelated deaths were labeled as competing risk events. A total of 931 NDMM patients were recruited in our study. The median follow-up was 23 months [interquartile range (IQR): 9-43 months]. Forty-two patients (4.51%) developed TEs, including 40 cases (4.30%) of venous thrombosis and 2 cases (0.21%) of arterial thrombosis. The median time from taking first-line treatment to TEs occurrence was 2.03 months (IQR: 0.52-5.70 months). The cumulative incidence of TEs was higher in patients treated with IMiDs than in those without IMiDs (8.25 vs. 4.32%, p = 0.038). There was no difference in the incidence of TEs between lenalidomide-based and thalidomide-based groups (7.80 vs. 8.84%, p = 0.886). Besides, TEs occurrence did not adversely affect OS (p = 0.150) or PFS (p = 0.210) in MM patients. Chinese NDMM patients have a lower incidence of thrombosis than those in western countries. The risk of thrombosis was particularly increased in patients treated with IMiDs. TEs were not associated with inferior progression-free survival or overall survival.