A Real-Life Survey of Venous Thromboembolic Events Occurring in Myeloma Patients Treated in Third Line with Second-Generation Novel Agents

Abstract

Compared to the general population, patients with multiple myeloma (MM) have a nine-fold increased risk of developing venous thromboembolism (VTE). Little is known about VTE prophylaxis in relapsed/refractory (RR) MM patients treated with next generation anti-myeloma drugs, such as pomalidomide (Poma) and carfilzomib (K), and monoclonal antibodies daratumumab (Dara) and elotuzumab (Elo), alone or in combination with dexamethasone at high- (D, 40 mg/week) or low-dose (d, 20 mg/week). Here, we describe the incidence of VTE in a retrospective cohort of 112 consecutive relapsed and refractory myeloma (RRMM) patients who received a third line of treatment from April 2013 to February 2020. Anti-MM regimens included combinations of pomalidomide and dexamethasone (PomaD, N = 61), carfilzomib, lenalidomide and dexamethasone (KRd, N = 31), and elotuzumab, lenalidomide and dexamethasone (EloRd, N = 10), while the remaining 10 patients received daratumumab as a single agent. According to National Comprehnsive Cancer Network (NCCN), International Myeloma Working Group (IMWG) and 2015 European Myeloma Network (EMN) guidelines, 42 patients (38%) were classified as high-risk patients. According to the IMPEDE VTE score, 32 patients (28%) were classified as low-risk, with a score ≤ 3 (most of them in the PomaD and Dara group), 70 (63%) were classified as intermediate-risk, with a score of 4-7 (most of them in PomaD and KRd group), and 10 (9%) were classified as high-risk, with a score ≥8 (most of them in the PomaD group). All patients received a prophylaxis, consisting generally of low-doses of acetylsalicylic acid. VTE was recorded in 9% of our patients, all of them with an intermediate or high-risk IMPEDE score, treated with low doses aspirin (ASA). No VTE occurred in patients treated with daratumumab. Thus, our real-life experience documents that (1) in RRMM patients treated with continuative regimens of third line, the incidence of VTE is similar to the setting of newly-diagnosed patients; (2) many patients in real-life received prophylaxis with ASA, irrespective of the risk classification; (3) the IMPEDE VTE score seems to be more appropriate to define the risk categories. Randomized clinical trials are required to better define the VTE prophylaxis strategy in the RRMM setting.

Keywords: carfilzomib; multiple myeloma; pomalidomide; venous thromboembolic events.

Figure 1

Regimens used as third-line of treatment in RRMM patients evaluated in this single-center retrospective study. The IMPEDE score was applied to distinguish patients in low, intermediate and high risk of VTE. For each treatment group, the VTE prophylaxis choice has been reported. Abbreviations: ASA: acetylsalicylic acid, LMWH: Low-molecular-weight heparin Dara: Daratumumab, EloRd: Elotuzumab, Lenalidomide, Desamethasone, KRd: Carfilzomib, Lenalidomide, Desamethasone, PomaD: Pomalidomide and Desamethasone.

Figure 2

Distribution of VTE among RRMM patients treated with novel agents as part of their second salvage regimen.