Calf Deep Vein Thrombosis Treatment Trial

Phase 4

Terminated

Brief Summary: The primary objective is to evaluate whether apixaban is more effective in treating patients with isolated calf vein thrombosis (DVT) than serial imaging of the DVT for preventing thrombus spread, pulmonary embolism (PE) and/or recurring DVTs.

Detailed Description: This is a randomized double-blind placebo controlled superiority clinical trial. Patients will be identified at the time of the diagnosis of acute calf deep vein thrombosis and approached at that time. If they agree they would be randomly assigned to placebo or apixaban treatment for three months. Along with this they will also undergo repeat ultrasounds at 7, 14, and 90 days along with telephone follow-up at 30 and 60 days.

Recruitment & Eligibility

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Arm && Interventions

Group	Intervention	Description
Placebo	Placebo	Patients will receive matching placebo.
Apixaban	Apixaban	Apixaban 5mg (10 mg twice daily for 7 days followed by 5 mg twice daily for 3 months).

Primary Outcome Measures

Name	Time	Method
Number of Subjects Who Experience Either Major Bleeding or Clinically Relevant Non-major Bleeding Within 3 Months	Within 3 months of therapy initiation	Major bleeding is defined as overt bleeding plus a hemoglobin decrease of ≥ 2 g/dL or transfusion of ≥ 2 units of packed red blood cells, or bleeding at a critical site: intracranial, intraspinal, intraocular, retroperitoneal, pericardial intra-articular, intramuscular with compartment syndrome, or fatal bleeding. Clinically relevant non-major bleeding is defined as any overt, actionable sign of hemorrhage meeting at least one of the following criteria: (i) requiring nonsurgical, medical intervention by a healthcare professional, (ii) leading to hospitalization or increased level of care, or (iii) prompting evaluation. All patients who received at least one dose of study medication will be included in the safety analysis. All suspected bleeding events will be evaluated by a central, blinded, independent adjudication committee.
Number of Subjects Who Experience a Composite Venous Thromboembolism (VTE) Event Within 3 Months	Within 3 months of therapy initiation	The composite VTE event will include thrombus propagation either within the calf veins or into proximal deep veins (popliteal, femoral or iliac veins), symptomatic or incidental VTE recurrence or all-cause mortality within 3 months of therapy initiation. All suspected VTE events will be evaluated by a central, blinded, independent adjudication committee.

Secondary Outcome Measures

Name	Time	Method
Net Clinical Benefit or Harm for the Two Strategies	Within 3 months of therapy initiation.	The outcome of net clinical benefit or harm will be assessed as the composite of the primary efficacy outcome or the principal safety outcome up to day 90. The difference in the incidences of the combined endpoint at 3 months between treatment arms will be estimated and tested using a normal approximation of the binomial distribution. All tests will be conducted at the two-sided 0.05 significance level.
Mean Time of Thrombus Propagation	Within 3 months of therapy initiation	The timing of thrombus propagation for those individuals who have suffered such an event. The date of thrombus propagation confirmation will be compared to the date of the original Deep Vein Thrombosis (DVT) diagnosis for this purpose.