Cancer-associated thrombosis (CT) is associated with a high risk of recurrent venous thromboembolic (VTE) events that require extended anticoagulation in patients with active cancer, putting them at risk of bleeding. The aim of the API-CAT study (NCT03692065) is to assess whether a reduced-dose regimen of apixaban (2.5 mg twice daily [bid]) is noninferior to a full-dose regimen of apixaban (5 mg bid) for the prevention of recurrent VTE in patients with active cancer who have completed ≥6 months of anticoagulant therapy for a documented index event of proximal deep-vein thrombosis and/or pulmonary embolism. API-CAT is an international, randomized, parallel-group, double-blind, noninferiority trial with blinded adjudication of outcome events. Consecutive patients are randomized to receive apixaban 2.5 or 5 mg bid for 12 months. The primary efficacy outcome is a composite of recurrent symptomatic or incidental VTE during the treatment period. The principal safety endpoint is clinically relevant bleeding, defined as a composite of major bleeding or nonmajor clinically relevant bleeding. Assuming a 12-month incidence of the primary outcome of 4% with apixaban and an upper limit of the two-sided 95% confidence interval of the hazard ratio <2.0, 1,722 patients will be randomized, assuming an up to 10% loss in total patient-years (β = 80%; α one-sided = 0.025). This trial has the potential to demonstrate that a regimen of extended treatment for patients with CT beyond an initial 6 months, with a reduced apixaban dose, has an acceptable risk of recurrent VTE recurrence and decreases the risk of bleeding.

中文翻译：

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使用全剂量或减量阿哌沙班对癌症相关静脉血栓栓塞患者进行延长抗凝治疗：API-CAT 研究的基本原理和设计

癌症相关血栓（CT）与复发性静脉血栓栓塞（VTE）事件的高风险相关，活动性癌症患者需要延长抗凝治疗，从而使他们面临出血风险。API-CAT 研究 (NCT03692065) 的目的是评估阿哌沙班减量方案（2.5 mg，每日两次 [bid]）在预防以下疾病方面是否不劣于阿哌沙班全剂量方案（5 mg bid）患有活动性癌症的患者因近端深静脉血栓形成和/或肺栓塞的记录指标事件已完成≥6个月的抗凝治疗，导致复发性 VTE。API-CAT 是一项国际、随机、平行组、双盲、非劣效性试验，对结果事件进行盲法裁决。连续患者随机接受阿哌沙班 2.5 或 5 mg bid，为期 12 个月。主要疗效结果是治疗期间复发症状或偶发 VTE 的综合结果。主要安全终点是临床相关出血，定义为大出血或非大临床相关出血的复合。假设使用阿哌沙班的 12 个月主要结局发生率为 4%，并且风险比的两侧 95% 置信区间上限 <2.0，则 1,722 名患者将被随机分组​​，假设总共损失高达 10%患者年（β = 80%；单侧 α = 0.025）。该试验有可能证明，对 CT 患者进行超过最初 6 个月的延长治疗方案并减少阿哌沙班剂量，具有可接受的 VTE 复发风险，并降低出血风险。