Efficacy of Prophylactic Low-Molecular Weight Heparin for Ambulatory Patients With Advanced Pancreatic Cancer: Outcomes From the CONKO-004 Trial

Purpose Advanced pancreatic cancer (APC), in addition to its high mortality, accounts for the highest rates of venous thromboembolic events (VTEs). Enoxaparin, a low-molecular weight heparin, is effective in prevention and treatment of VTEs. Some small studies have indicated that this benefit might extend to patients with cancer. Patients and Methods Patients with histologically proven APC were randomly assigned to ambulant first-line chemotherapy and prophylactic use of enoxaparin or chemotherapy alone to investigate the probable reduction in symptomatic VTEs and the impact on survival. Results A total of 312 patients were recruited as one of the protocol end points was reached. Within the first 3 months, the numbers of symptomatic VTEs were as follows: 15 of 152 patients in the observation group and two of 160 patients in the enoxaparin group (hazard ratio [HR], 0.12; 95% CI, 0.03 to 0.52; P-2 = .001). The numbers of major bleeding events were as follows: five of 152 patients in the observation arm and seven of 160 patients in the enoxaparin arm (HR, 1.4; 95% CI, 0.35 to 3.72; P-2 = 1.0). Overall cumulative incidence rates of symptomatic VTEs were 15.1% (observation) and 6.4% (enoxaparin; HR, 0.40; 95% CI, 0.19 to 0.83; P = .01). Progression-free (HR, 1.06; 95% CI, 0.84 to 1.32; P = .64) and overall survival (HR, 1.01; 95% CI, 0.87 to 1.38; P = .44) did not differ between groups. Conclusion This study demonstrates the high efficacy and feasibility of primary pharmacologic prevention of symptomatic VTEs in outpatients with APC. Treatment efficacy was not affected by simultaneous treatment with enoxaparin in this trial setting.