Abstract 2703: Final results of a phase 2 trial using a novel, non-anthracycline neoadjuvant chemotherapy regimen in Her2-positive breast cancer

Abstract

Abstract Background: The addition of trastuzumab to preoperative chemotherapy for Her2-positive breast cancers has been shown to increase pCR rate, which correlates with improved outcome. The purpose of this study was to evaluate the efficacy of trastuzumab in combination with dose-dense nab-paclitaxel followed by weekly vinorelbine. Methods: Patients with Stage I (>1.0 cm), II, or IIIA Her2-positive (defined as either immunohistochemical 3+ of fluorescence in situ hybridization-positive) breast cancer received nab-paclitaxel 260 mg/m2 iv every 2 weeks for 4 cycles in combination followed by vinorelbine 25 mg/m2 iv weekly with simultaneous trastuzumab (4 mg/kg loading dose then 2 mg/kg weekly) for 20 weeks. Tissue was collected at baseline, at optional midway biopsy, and post-therapy. Primary endpoint was pCR rate; secondary endpoints included response rate and toxicity. Cardiac evaluation was performed at baseline, after 4 cycles of nab-paclitaxel, after 12 weeks of vinorelbine and every 3 months thereafter per standard practice guidelines. Results: To date, 27 patients have been accrued (3/2008 to 6/2011). 24 patients are currently evaluable for primary endpoint. Patients were accrued from a university center (48.2%), county hospital (11.1%), and community sites (40.7%). Median age was 49.5 years (34-64). Median tumor size was 4.0 cm (1.5-7cm). 14 of 27 patients (51.9%) were clinically node-positive at study entry. 11 patients were African American (40.7%), 16 were Caucasian (59.3%). The regimen was well-tolerated: 3 patients experienced grade 3 neuropathy; 6 patients had grade 3 neutropenia; 1 patient had trastuzumab held for asymptomatic decrease in left ventricular ejection fraction. 18 of 24 patients (75%) had complete clinical response rate. 6 of 24 patients (25%) had partial clinical response. 11 of 24 patients (45.8%) had pCR. Conclusions: The combination of preoperative trastuzumab with dose-dense nab-paclitaxel followed by vinorelbine was well-tolerated and resulted in a high rate of pCR in Her2-positive, early-stage breast cancer. Final results and correlative studies will be reported. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2703. doi:1538-7445.AM2012-2703