Thromboprophylaxis in multiple myeloma patients treated with lenalidomide - A systematic review.

Background: Studies have consistently demonstrated the need for venous thromboembolism (VTE) prophylaxis in patients with newly diagnosed multiple myeloma (NDMM) or relapsed refractory multiple myeloma (RRMM), receiving lenalidomide-based therapy. However, the optimal approach has not yet been established.

Objective: To compare the efficacy of aspirin (ASA) and low molecular weight heparin (LMWH) prophylaxis in patients with myeloma using lenalidomide-based therapy.

Results: Six studies were included with 1125 adult participants with NDMM or RRMM treated with lenalidomide-based therapy with thromboprophylaxis with ASA or LMWH. Pooled data of studies of NDMM showed that the risk of VTE in patients on ASA was 1.5 per 100 patient-cycles with a total risk of VTE of 98 of 915 (10.7%) [95% CI: 8.86-12.88] compared to 3 of 211 (1.4%) [95% CI: 0.48-4.09] with LMWH in NDMM and RRMM patients. Our study demonstrated a significantly higher VTE risk for patients receiving lenalidomide plus high-dose dexamethasone (RD) on ASA prophylaxis compared to lenalidomide plus low-dose dexamethasone (Rd) [RR=2.5 (95% CI: 1.68-3.96), P<0.0001]. Furthermore, patients who received lenalidomide and dexamethasone alone had a significantly higher risk of VTE compared to those on MPR while on ASA prophylaxis (RR=6.4 [(95% CI: 4.11-9.91), P<0.0001]).

Conclusion: The most frequent thromboprophylaxis option used for myeloma patients on lenalidomide-based therapy is ASA. However, ASA may not confer appropriate thromboprophylaxis in patients using RD, but may be a safe option with MPR. In future studies, the IMWG VTE risk stratification criteria should be validated, incorporating the thromboprophylaxis option accordingly. More studies comparing the efficacy and safety of ASA to LMWH are warranted.