Strategies for anticoagulation in patients with thrombocytopenia and cancer-associated thrombosis (START): design and rationale of the START pilot randomized controlled trial

Patients with cancer have high risks of venous thromboembolism (VTE) as well as thrombocytopenia. Thrombocytopenia is associated with an increased risk of bleeding. Hence, treatment of acute VTE with anticoagulation is challenging in patients with cancer and thrombocytopenia. Data are limited in the management of this condition, and there are no randomized controlled trials (RCTs) available. The strategies for anticoagulation in patients with thrombocytopenia and cancer-associated thrombosis pilot trial (NCT05255003) is an open-label pilot RCT to evaluate the feasibility of a full-scale trial in this population. Adult patients with acute cancer-associated thrombosis within 14 days and thrombocytopenia (platelet count < 50,000/μL) are randomly assigned to 2 treatment arms as follows: (1) modified-dose low-molecular-weight heparin based on a predefined regimen to adjust dose by platelet count; or (2) platelet transfusion with a higher dose low-molecular-weight heparin regimen. The primary feasibility outcome is the overall average number of patients recruited per month. The main clinical outcomes include clinically relevant bleeding events (composite of major bleeding and clinically relevant nonmajor bleeding) and objectively confirmed recurrent VTE. This trial has the potential to define care in patients with acute cancer-associated thrombosis and thrombocytopenia. In this article, we present the rationale and design of the pilot trial and highlight several unique aspects of the study.