Oral vinorelbine (NVBo) and anastrozole (A) as neoadjuvant treatment of locally advanced (LA) breast cancer (BC) in hormone receptor positive (HR+) postmenopausal patients: Results of an international phase II trial

600 Background: Two recent randomized studies with anastrozole, as single agent or with an unspecified cytotoxic, produced an objective response rate (RR) of 24 and 39.5% by ultra-sound (US) [baseline primary tumor diameters (PTD) of 2.6 cm (median) and 3.6 cm (mean), respectively] in LA BC. This trial assessed the effect of the combined NVBo-A therapy. Methods: 55 assessable HR+ patients (pts) with LA breast cancer (tumor size > 3 cm) were expected, including 10 with pharmacokinetics (PK). Pts received 3 (if progression or complete response) to 6 courses of NVBo at day 1(D1) and 8 every 3 weeks (60 mg/m2 escalated to 80 mg/ m2 at cycle 2) with 1 mg of A daily. Both US (primary criteria) and calliper assessments were performed at cycle 3 and 6, with surgery within 4 weeks of the last D1 NVBo. Anastrozole interaction on NVBo was studied by comparing NVBo PK between D1 and D8. NVBo interaction on A was assessed by comparing trough concentrations between D8 and D21. Results: Between July 2005 and June 2008, ...