The API-CALF Study: Apixaban to Treat Calf Vein Thrombosis (NCT04981327) | Clinical Trial Compass
Not Yet RecruitingPhase 3
The API-CALF Study: Apixaban to Treat Calf Vein Thrombosis
1,300 participantsStarted 2022-09-01
Plain-language summary
Isolated distal DVT (iDDVT) is the most frequent clinical presentation of VTE and is associated with a significant morbidity and risks of long-term complications. Data from clinical trials highlighted that patients with iDDVT might require some level of AC treatment. However, the optimal anticoagulant intensity is uncertain, and it is plausible that the best benefit/risk ratio for AC might be achieved with lower intensity doses rather than therapeutic doses.
The principal research question of the Apixaban to treat calf vein thrombosis (API-CALF) study is to determine whether, after a conventional course of 7 days of Apixaban 10mg BID, Apixaban 2.5mg BID (experimental arm) is non inferior to Apixaban 5 mg BID (standard arm) in preventing VTE recurrence and bleeding in patients with iDDVT. Patients will be treated with Apixaban for a total of 3 months. In that perspective we will conduct an international multicentre open-label assessor-blinded study
Who can participate
Age range
18 Years – 120 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion Criteria:
Consecutive patients with acute (symptoms \<10 days) symptomatic iDDVT diagnosed on leg CUS who have none of the following exclusion criteria and who provided informed consent to participate. Diagnosis of iDDVT is made in the presence of an incompressible distal deep vein (deep calf vein (posterior tibial, anterior tibial or peroneal veins) or muscular vein (soleal or gastrocnemius veins)).
Exclusion Criteria:
* Age \< 18 years
* Ipsi or contralateral Proximal DVT
* Distal DVT involving the tibio-peroneal trunk (i.e. calf trifurcation)
* DVT occurring while on anticoagulation (started ≥48hours before DVT diagnosis); However, inpatients that developed their iDDVT while on prophylactic anticoagulation are eligible if their expected date of discharge is \<6 days post randomization.
* Clinically suspected PE (patient eligible if PE ruled out with objective tests)
* Active cancer, receiving cancer treatment or cured for \< 6 months
* Indication for long-term therapeutic anticoagulation (e.g. atrial fibrillation, mechanical heart valve…)
* Thrombocytopenia (platelet count \<100 g/l)
* Severe renal impairment (creatinine clearance \<30 ml/min)
* Liver disease (including Child-Pugh Class B and C) associated with coagulopathy
* Pregnant or breast-feeding woman
* Body weight \>120kg or \<40 kg
* Ongoing active bleeding or condition at high risk of bleeding with anticoagulation (e.g. peptic ulcer…)
* Treatment with daily NSAIDs (aspirin ≤160 mg/day or clopidogrel …
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Rate of i) symptomatic VTE; ii) major bleeding and clinically relevant non major bleeding (CRNMB); iii) VTE and bleeding related death.