Challenges in Trials in Sickle Cell Disease: Thromboprophylaxis in Sickle Cell Disease With Central Venous Catheters (THIS) Pilot Study.

Individuals with sickle cell disease (SCD) often require central venous catheter (CVC) use; however, this is associated with a high incidence of venous thromboembolism (VTE). We conducted a pilot randomized controlled trial (RCT) to assess if it is feasible and safe to conduct an adequately powered RCT comparing rivaroxaban to placebo as thromboprophylaxis in adult SCD participants with CVC. In this pilot investigator-initiated, double-blinded, multi-center RCT, we assessed feasibility outcomes to explore if a full RCT is possible, and also exploratory outcomes of thrombosis and bleeding. THIS pilot trial was closed prematurely due to slow recruitment, lack of funding, and non-feasibility of the complete trial. Of 21 participants who met eligibility criteria, 4 were recruited into the study. Adherence to study procedures was 100% and loss to follow-up was 0%. One participant was noted to have a VTE during follow-up, but of unknown chronicity. Another participant developed a new VTE post-randomization, but prior to starting study drug. No major or clinically relevant bleeding events occurred during study follow-up. Challenges in running the study were largely due to a limited eligible population, and low participation interest in study involvement. Trial Registration: ClinicalTrials.gov identifier: NCT05033314.