Use of apixaban for 30 days after hospital discharge of patients treated for COVID-19 was associated with slight reductions in death and thromboembolic complications, according to ACTIV-4C study group investigators. However, the results were imprecise and incomplete because the study was terminated early since the event rate was lower than anticipated and COVID-19 hospitalizations were declining in the U.S. at the time of the study.
The prospective, randomized, double-blind, placebo-controlled clinical trial included adults hospitalized with COVID-19 for 48 hours or more and ready for discharge. Patients with another indication for or a contraindication to anticoagulation were excluded. Participants received apixaban 2.5 mg or placebo twice daily for 30 days.
Based on a primary efficacy end point of a 30-day composite of death, arterial thromboembolism, and venous thromboembolism, and primary safety end points of 30-day major bleeding and clinically relevant nonmajor bleeding, the researchers found: “Enrollment was terminated early, after 1,217 participants were randomly assigned, because of a lower than anticipated event rate and a declining rate of COVID-19 hospitalizations. Median age was 54 years, 50.4% were women, 26.5% were Black, and 16.7% were Hispanic; 30.7% had a World Health Organization severity score of 5 or greater, and 11.0% had an International Medical Prevention Registry on Venous Thromboembolism risk prediction score of greater than 4. Incidence of the primary end point was 2.13% (95% CI, 1.14 to 3.62) in the apixaban group and 2.31% (CI, 1.27 to 3.84) in the placebo group. Major bleeding occurred in 2 (0.4%) and 1 (0.2%) and clinically relevant nonmajor bleeding occurred in 3 (0.6%) and 6 (1.1%) apixaban-treated and placebo-treated participants, respectively. By day 30, thirty-six (3.0%) participants were lost to follow-up, and 8.5% of apixaban and 11.9% of placebo participants permanently discontinued the study drug treatment.”