ORLANDO – Enoxaparin and aspirin were equally effective at preventing thrombotic events in young, newly diagnosed myeloma patients who were treated with a lenalidomide-based regimen in a randomized trial.
Previous studies have shown that this patient population is at least three times as likely to develop thrombosis as patients not on a lenalidomide-based regimen, said Dr. Alberto Rocci of the University of Torino (Italy). "Randomized trials comparing different therapies for [venous thromboembolism] prophylaxis in young, newly diagnosed myeloma patients are still lacking," he said at the annual meeting of the American Society of Hematology.
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In this study, Dr. Rocci and his colleagues enrolled 402 patients younger than 65 years from 62 cancer centers. All patients had symptomatic and measurable disease, with organ damage.
All patients underwent four 28-day cycles of lenalidomide (25 mg/day on days 1-21) and dexamethasone (40 mg/day on days 1, 8, 15, and 22). After this treatment, 202 patients were randomized to six 28-day cycles of melphalan (0.18 mg/kg on days 1-4), prednisone (2 mg/kg on days 1-4), and lenalidomide (10 mg/day on days 1-21); and 200 patients were randomized to two courses of melphalan (200 mg/m2, plus stem cell support). These groups were designated MPR and MEL 200, respectively.
In this substudy, the researchers further randomized eligible patients who received lenalidomide during induction and in the MPR consolidation regimen: 166 patients were assigned to 40 mg of enoxaparin (Lovenox) per day and 176 patients to 100 mg of aspirin per day. Sixty patients were excluded from this randomization because they had a high risk of bleeding or indications for anticoagulant or antiplatelet therapy. Patient demographics and risk factors for thrombotic events were similar between the two groups assessed for venous thromboembolism (VTE) prophylaxis.
The cumulative incidence of all thrombosis, major bleeding, acute cardiovascular events, and sudden deaths was 1.8% in the enoxaparin group and 5.2% in the aspirin group (P = .06). No incidents of major bleeding or sudden death were reported during the study.
During the induction phase of therapy, the incidence of any thrombosis was 1.2% in the enoxaparin group vs. 1.7% in the aspirin group. The events included three cases of deep vein thrombosis (two in the enoxaparin group and one in the aspirin group) and three pulmonary embolisms in the aspirin group.
The time to onset of any thrombotic events was similar between the groups, and the results suggest that the risk of thrombosis is highest during the first 4-6 months of treatment, Dr. Rocci noted.
The relatively low incidence of thrombosis confirms the safety of the dexamethasone/lenalidomide regimen, said Dr. Rocci. The findings also confirm the safety of low-molecular-weight heparin as the standard for preventing thrombosis in newly diagnosed multiple myeloma patients, he said. Aspirin can be a possible alternative in multiple myeloma patients with low risk for developing VTE, he added.
Dr. Rocci had no financial conflicts to disclose. Several of his coauthors disclosed receiving honoraria or research funding from, or serving as a consultant or member of an advisory committee or on the board of directors for, Celgene and Janssen-Cilag.