Abstract OT1-02-01: Phase II neoadjuvant trial of nanoparticle almumin-bound paclitaxel and trastuzumab in patients with node-negative, Her-2 positive breast cancer (OMC-BC04)

Abstract

Abstract Background: Neoadjuvant chemotherapy plus trastuzumab results in a 30% to 50% pathologic complete response (pCR) rate in HER-2 positive breast cancer and has been associated with improved therapeutic outcomes. Thus, the pCR rate can be useful in evaluating novel agents in this patient population. Albumin-bound (nab)-paclitaxel can reduce the toxicity of Paclitaxel while maintaining its efficacy. We reported that neoadjuvant therapy using Anthracycline based regimens (EC,AC,FEC) followed by a combination with nab-Paclitaxel and Trastuzumab was effective and safe by OMC-BC01 Study (Tanaka et al. Clin Breast Cancer 15:191-196). The pCR rate was 36% and 71% in the patients with estrogen receptor-positive and negative cancer, respectively. In addition, Tolaney et al. showed that adjuvant Paclitaxel and Trastuzumab for node-negative, HER-2 positive tumors measuring up to 3 cm in greatest dimension was associated with patients outcomes that were better than expected on the basis of historical data (Tolaney et al. N Engl J MED.2015 Jan 8:372(2):134-141). We conducted a clinical Phase II, multicenter, neoadjuvant trial of combination with nanoparticle albumin-bound Paclitaxel and Trastuzumab in patients with node-negative, Her-2 positive, estrogen receptor-negative breast cancer measuring up to 3 cm in greatest dimension. Patients and Methods: nab-Paclitaxel and Trastuzumab as neoadjuvant therapy in patients with Her-2 positive, node-negative, estrogen receptor-negative breast cancer measuring up to 3 cm in greatest dimension. Patients are treated with neoadjuvant nab-Paclitaxel (260mg/m2) and Trastuzumab q21d x 4, and undergo surgery 4-6 weeks later from completing chemotherapy. The primary endpoint, pCR is defined as no evidence of invasive tumors in the final surgical sample both in the breast and axillary lymph nodes. Secondary endpoints include objective clinical response rate, histological response rate, disease-free interval, rate of breast conserving surgery, and the safety of the treatment. Accrual: Presently, a total number of 1 patient have been included since start of the study. The expected end of accrual of 30 patients will be the last quarter 2018. Citation Format: Iwamoto M, Tanaka S, Koda C, Kawaguchi K, Terasawa R, Sato N, Fujioka H, Kimura K, Uchiyama K. Phase II neoadjuvant trial of nanoparticle almumin-bound paclitaxel and trastuzumab in patients with node-negative, Her-2 positive breast cancer (OMC-BC04) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr OT1-02-01.