Abstract OT2-18-01: Nab-paclitaxel followed by dose-dense epirubicin/cyclophosphamide in neoadjuvant chemotherapy for triple-negative breast cancer: an open-label, single-arm phase II study

Abstract

Abstract Purpose: The anti-tumor activity of nab-paclitaxel followed by epirubicin/cyclophosphamide (EC) as neoadjuvant chemotherapy (NAC) in Asian patients remains unclear, particularly in the aggressive subtype triple-negative breast cancer (TNBC). This study aimed to evaluate the efficacy and safety of this NAC regimen in TNBC. Methods: In this Simon’s two-stage, phase II study, treatment-naïve patients with resectable unilateral primary invasive TNBC were enrolled. Eligible patients received nab-paclitaxel 125 mg/m2 weekly on day 1 for 12 weeks, followed by dose-dense EC (epirubicin 90 mg/m2; cyclophosphamide 600 mg/m2) on day 1 for four 2-week cycles. The primary endpoint was the total pathological complete response (tpCR, ypT0/is ypN0) rate. Secondary endpoints included breast pathological complete response (bpCR, ypT0/is) rate, objective response rate (ORR), the proportion of patients requiring breast-conserving surgery, and safety. Results: 55 eligible patients were enrolled and treated. After neoadjuvant therapy, tpCR and bpCR were respectively observed in 43.1% (95% CI, 29.3%-57.8%) and 49.0% (95% CI, 3)4.8%-63.4%) of 51 evaluable patients for pathological response evaluation. 44 had an ORR as their best response (80.0%; 95% CI, 67.0%-89.6%). No correlations between clinicopathological variables and pathological/clinical response were observed. Grade 3 or more AEs occurred in 63.6% of 55 patients. The most frequent AEs were alopecia. No treatment-related surgical delay or death occurred. Conclusions: Nab-paclitaxel followed by dose-dense EC as NAC demonstrates promising anti-tumor activity and acceptable tolerability for patients with TNBC. Citation Format: Yin Liu, Lei Fan, Zhi-Ming Shao, Zhong-Hua Wang. Nab-paclitaxel followed by dose-dense epirubicin/cyclophosphamide in neoadjuvant chemotherapy for triple-negative breast cancer: an open-label, single-arm phase II study [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr OT2-18-01.