Capecitabine and bevacizumab with or without vinorelbine in first-line treatment of HER2/neu-negative metastatic or locally advanced breast cancer: final efficacy and safety data of the randomised, open-label superiority phase 3 CARIN trial

The study was designed to evaluate efficacy and superiority of capecitabine/bevacizumab + vinorelbine (CAP/BEV/VIN) compared to CAP/BEV alone. Main purpose was to introduce a taxane-/anthracycline-free first-line treatment in advanced breast cancer (ABC), in order to avoid long-term toxicities. In this open-label, superiority, phase 3 trial, patients with HER2-negative ABC were randomized 1:1 to receive either oral CAP at 1000 mg/m2 [twice daily, days 1–14, q3w] plus intravenous BEV at 15 mg/kg [day 1, q3w] (arm A) or in addition to this protocol intravenous VIN at 25 mg/m2 [days 1 + 8, q3w] (arm B) until disease progression, unacceptable toxicity or withdrawal of consent. Between 26 February 2009 and 26 October 2012, we randomised 600 patients (arm A N = 300; arm B N = 300) from 57 German outpatient-centres and 2 university hospitals. Median progression-free survival (PFS) (primary endpoint) was not improved with VIN (CAP/BEV, 8.8 months; CAP/BEV/VIN, 9.6 months; HR 0.84 [95 % CI 0.70–1.01], P = 0.058). Median overall survival (OS) (secondary endpoint) was 25.1 and 27.2 months for CAP/BEV and CAP/BEV/VIN, respectively, average HR 0.85 [95 % CI 0.70–1.03], P = 0.104). The 1- and 2-year OS rates appeared to be similar (78.0 and 77.0 %; 53.0 and 54.0 %). Toxicity profiles were generally mild and manageable. Adverse events occurred more frequently in arm B. Regarding the balance between clinical efficacy (PFS, OS) and toxicity, the CAP/BEV combination provides a favourable treatment option in first-line ABC avoiding taxane- and/or anthracycline-induced long-term toxicity. Superiority of CAP/BEV/VIN was not met, and side effects were even enhanced. Nevertheless, no safety issues occurred.