Thrombosis Therapy Duration: The Kids-DOTT Study – Phase III

Prospective Evaluation of the Duration of Therapy for Thrombosis in Children

Protocol Description

This study is being done to find out how long to treat blood clots in a vein by balancing the risks of bleeding versus recurrence of clotting. The study uses images of the clot, performed as part of a patient’s standard care after the initial treatment. Typically blood thinners are administered for 3 months or longer, but researchers believe in some cases treatment may not be necessary beyond 6 weeks.

Study Level: Phase III

Eligibility Criteria

Subject to certain exclusion criteria, this study is accepting patients of both genders, through age 20, diagnosed with radiologically confirmed acute venous thrombosis.
Males and Females: Through age 20


Initially, all participants will receive standard clinical care through the use of blood thinners as therapy for their blood clots. At the 6-week evaluation, if imaging (ultrasound/scan) indicates that the blood clot has resolved or only partially occluded the flow of blood through the vein, study participants will be randomly assigned to either continue taking blood thinners for another 6 weeks, or discontinue the use of blood thinners. If imaging at 6 weeks indicates that the vein continues to be blocked by a clot, or if it is determined that the participant has the persistent antiphospholipid antibody, they will continue the use of blood thinners for the remaining 6 weeks of the study.
Visits: Up to 9, same as with standard care
Duration: Up to 2 years

Status: Open to Enrollment

Source(s) of Support

National Heart, Lung, and Blood Institute of the National Institutes of Health
Johns Hopkins All Children’s Hospital of St. Petersburg, Florida

Primary Investigator

James D. Cooper, MD

Contact Information

For more information about the study or enrollment, please contact:
Angela Martino, BSN, RN