The comparative effectiveness of direct oral anti-coagulants and low molecular weight heparins for prevention of recurrent venous thromboembolism in cancer: The CANVAS pragmatic randomized trial.
Deborah Schrag, Hajime Uno, Rachel Rosovsky, Cynthia Rutherford, Kristen M. Sanfilippo, John L. Villano, Monic R. Drescher, Nagesh Jayaram, Chris E. Holmes, Lawrence Feldman, Ottavia Zattra, Christine Cronin, Ethan Basch, Anna Weiss, Jean M. Connors, CANVAS Investigators
Abstract
12020 Background: Previous randomized trials in cancer patients suggest that DOACs are non-inferior to LMWH for preventing recurrent VTE but have higher risk of bleeding. However, the balance of benefits and burdens remains uncertain. Objective: The CANVAS pragmatic trial compared recurrent VTE, bleeding and death in cancer patients following an initial VTE treated with either DOAC or LMWH therapy. Methods: CANVAS was an unblinded hybrid comparative effectiveness non-inferiority trial, with randomized and preference cohorts. Between 12/16 and 4/20, 671 participants were randomized and followed for 6-months. Between 12/16 and 12/17, 140 participants declined randomization, chose their preferred anticoagulant and were followed for 6-months. The preference cohort was closed when predetermined stopping criteria were met. Final follow-up was 11/30/20. Randomized patients were assigned 1:1 to receive either a DOAC or a LMWH. If assigned to LMWH, transitions to warfarin were allowed. Physicians and patients could choose among any DOAC or LMWH. Doses were suggested based on FDA-approved labeling but not mandated. Patients from 67 practices in the US with any invasive solid tumor, lymphoma, multiple myeloma or CLL and a diagnosis of symptomatic or radiographically detected VTE within 30 days of enrollment were eligible. The 1° analysis was conducted in the randomized modified-into to treat popululation, (all subjects who received study drug). The 1° outcome was recurrent VTE. The aim was to establish noninferiority of anticoagulation with a DOAC as defined by the upper limit of the 2-sided 90% CI for the difference in the event rate at 6 months of < 3%. Secondary outcomes included death and bleeding. Hypothesis testing included only the randomized cohort but propensity score adjusted results for the preference and combined cohorts are also shown. Results: The non-inferiority criteria for recurrent VTE was met. Conclusions: Among adult cancer patients with VTE, the use of a DOAC compared with a LMWH resulted in a noninferior risk of recurrent VTE with no differences in rates of bleeding or death in randomized patients. Clinical trial information: NCT02744092. [Table: see text]