Nab-paclitaxel Followed by Dose-dense Epirubicin/Cyclophosphamide in Neoadjuvant Chemotherapy for Triple-negative Breast Cancer: A Phase II Study

BACKGROUND: The anti-tumor activity of nab-paclitaxel followed by epirubicin/cyclophosphamide (EC) as neoadjuvant chemotherapy (NAC) in Asian patients remain 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 unilateral primary invasive TNBC were enrolled. Eligible patients received nab-paclitaxel 125 mg/m(2) weekly on day 1 for 12 weeks, followed by dose-dense EC (epirubicin 90 mg/m(2); cyclophosphamide 600 mg/m(2)) on day 1 for four 2-week cycles. The primary endpoint was the total pathological complete response (tpCR, ypT0/is ypN0) rate. RESULTS: A total of 55 eligible patients were enrolled and treated. After NAC, tpCR and breast pathological complete response were respectively observed in 43.1% (95% CI, 29.3-57.8) and 49.0% (95% CI, 34.8-63.4) of 51 evaluable patients for pathological response evaluation. 44 had an objective response 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 adverse events (AEs) occurred in 63.6% of 55 patients. The most frequent AEs were alopecia. No treatment-related surgical delay or death occurred. CONCLUSION: Nab-paclitaxel followed by dose-dense EC as NAC demonstrates promising anti-tumor activity and acceptable tolerability for patients with TNBC. (ClinicalTrials.gov Identifier: NCT03799679).