ACTIV IV ACUTE: Anti-thrombotics for Adults Hospitalized With COVID-19

Platform trial comparing the effectiveness of multiple open label antithrombotic strategies for prevention of adverse outcomes in COVID-19 positive inpatients. Bayesian design where each therapy is a separate arm, and an efficacious arm may become the reference arm for comparison with new arms.
For further information:
Agent A VS. Agent B (reference)

Key Personnel

Judith Hochman, MD Judith.Hochman@nyulangone.org212-236-6927
Matthew Neal, MD nealm2@upmc.edu412-692-2850

Primary Outcome(s)

Days free of organ support.
Ordinal count of the number of days a participant is alive and free of organ support through 21 days after enrollment.


Adults hospitalized for COVID-19 and expected to remain in hospital longer than 72 hours.


Therapeutic heparin above standard of care or standard of care prophylactic dose of heparin.

Planned Enrollment

Up to 1,000 per arm as arms are added.

Power and Interim Assessments

Power is dependent on sample size. Some generic calculations:

  • 1,000 vs. 1,000 will have 80% power for an odds ratio change of 1.25
  • 400 vs. 400 will have 90% power for and odds ratio change of 1.5
  • 200 vs 200 will have 90% power for an odds ratio change of 2.0

Interim analysis at 20, 40, 60, 80 and 100 percent enrollment.


Earliest Day 28 or hospital discharge with potential contact up to 1 year after discharge.