PD07-07: Combination of Paclitaxel and Bevacizumab without or with Capecitabine as First-Line Treatment of HER2−Negative Locally Recurrent or Metastatic Breast Cancer (LR/MBC): First Results from a Randomized, Multicenter, Open-Label, Phase II Study of the Dutch Breast Cancer Trialists' Group (BOOG).

Abstract

Background: First-line treatment of HER2−negative LR/MBC with paclitaxel (T) and bevacizumab (A) has demonstrated improved progression-free survival (PFS) and overall response rate (ORR) when compared with T alone (E2100). We determined whether addition of capecitabine (X) to AT is safe and would be better effective than AT in women with HER2−negative LR/MBC. Methods: Eligibility criteria were age ≥18 & ≤75 years, measurable or non-measurable HER2−negative LR/MBC, ECOG PS 0–1 and no prior chemotherapy for LR/MBC. Patients were randomized in 1:1 ratio to receive AT (4-week cycle of T 90 mg/m2 on days 1, 8, 15 and A 10 mg/kg on days 1, 15 for 6 cycles, followed by A 15 mg/kg on day 1 given 3-weekly for subsequent cycles) or ATX (3-week cycle of T 90 mg/m2 on days 1, 8, A 15 mg/kg on day 1 and X 825 mg/m2 bid on days 1–14 for 8 cycles, followed by A 15 mg/kg on day 1 and X 825 mg/m2 bid on days 1–14 given 3-weekly for subsequent cycles). Treatment was discontinued at disease progression, unmanageable toxicity or withdrawal of consent. The primary endpoint was PFS. Secondary endpoints were overall survival, ORR, duration of response and toxicity. Efficacy was evaluated according to RECIST 1.0 and toxicity was assessed according to NCI CTCAE 3.0. Results: From June 2007 till December 2010, 312 patients were recruited at 36 sites. The median age was 56 years (range 32–76). Among all patients, 52% had ECOG 0, 85% were hormone-receptor positive, 86% had measurable disease and 8% had bone-only metastases. These factors were well balanced between both arms. A total of 48% and 33% of patients, respectively, received prior hormonal therapy or radiotherapy for LR/MBC. At the data cut-off of 1st June 2011, the median follow-up duration was 23 months. 311 patients received at least one cycle of treatment and were evaluable for safety. The median number of treatment cycles in AT was 9 and in ATX was 11 (both 33 weeks). An ORR of ≥40% was reached in patients with measurable disease in both groups. The incidence of serious adverse events (SAEs) was 47% and 40% for AT and ATX, respectively, while that of treatment-related SAEs was 12% and 19%, respectively. Treatment-related deaths were 2% for AT and 2% for ATX. The overall rate of AEs grade 3 or 4 was similar in both arms as shown in Table 1, except for hand-foot syndrome grade 3 and neutropenia grade 3 in ATX. In addition, 6 patients with pulmonary embolism were reported in ATX. Conclusions: ATX was well tolerable, although more patients experienced hand-foot syndrome grade 3 and thromboembolic events than patients treated with AT. The efficacy data will be presented at the meeting. Support: This study was supported by Roche. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr PD07-07.