Management of Recurrent Venous Thromboembolism During Anticoagulant Treatment in Cancer Patients - a Prospective Cohort Study

Objective: To prospectively evaluate clinical outcomes during guideline-recommended LMWH dose escalation for recurrent VTE during LMWH or DOAC treatment for cancer-associated thrombosis.

Study design: International, prospective, observational cohort study Study population: Adult cancer patients with symptomatic or incidental recurrent VTE while receiving LMWH or DOACs for acute VTE are eligible. Main exclusion criteria include anticoagulant treatment for the recurrent VTE for more than 72 hours, severe hepatic dysfunction, active bleeding, recent major surgery, uncontrolled hypertension, known bleeding diathesis, and a life expectancy of less than 1 month.

Study procedures: Patients will be managed at the discretion of the treating physician, who will be encouraged to follow guideline recommendations. These guidelines suggest supra-therapeutic dose LMWH for 4 weeks (+/- 5 days) followed by therapeutic dose LMWH or therapeutic dose DOAC, while it is suggested to treat patients with VTE recurrence during maintenance dose LMWH (i.e. 75 to 80% of full therapeutic weight adjusted dose) with therapeutic dose of LMWH or DOAC.

Main study parameters/endpoints: The co-primary outcomes are new symptomatic or incidental recurrent VTE during 3 months of follow-up and on-treatment major bleeding. Secondary outcomes include recurrent incidental VTE, recurrent symptomatic VTE, recurrent incidental or symptomatic proximal or distal DVT, recurrent incidental or symptomatic PE, clinically relevant non-major bleeding, all-cause mortality, and cancer-related mortality. VTE occurring at other sites such as cerebral DVT or splanchnic DVT will also be recorded.