Dose-Dense Nab-Paclitaxel Improves RCB 0/I Rate in HR+/HER2- Breast Cancer

In a multicentre, randomised, phase III trial conducted across three hospitals in China (ClinicalTrials.gov ID: NCT04182568), researchers evaluated whether a dose-dense neoadjuvant bi-weekly nanoparticle albumin-bound (nab)-paclitaxel regimen improves pathological response compared with bi-weekly docetaxel in patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative (HR+/HER2-) early breast cancer.

Between December 2019 and December 2020, 388 patients with cT1-3/N0-1/M0 disease were randomised 1:1 (194 per arm) via dynamic allocation with Pocock minimisation based on Ki-67 and TNM stage. The experimental group received intravenous nab-paclitaxel (260 mg/m² every two weeks for four cycles), while the control group received docetaxel (100 mg/m² on the same schedule). Both arms subsequently received epirubicin (90 mg/m²) plus cyclophosphamide (600 mg/m²) every two weeks for four cycles. The primary endpoint was residual cancer burden (RCB) 0/I rate, with secondary endpoints including disease-free survival (DFS), overall survival (OS), and safety.

The nab-paclitaxel cohort achieved an RCB 0/I rate of 20.1% (95% CI 14.41–26.72), significantly exceeding the docetaxel cohort's 11.34% (95% CI 6.92–15.81; χ²=5.62, P = 0.018). Pathological complete response (pCR) occurred in 15.98% (95% CI 10.81–21.16) of the nab-paclitaxel arm versus 10.31% (95% CI 6.01–14.60) of the docetaxel arm (χ²=2.73, P = 0.098). Multivariate analysis confirmed a statistically significant favourable impact of nab-paclitaxel on RCB 0/I. Survival outcomes remained comparable, with 5-year DFS reaching 90.21% versus 87.11% (HR: 1.14, 95% CI 0.64–2.05; P = 0.656) and 5-year OS reaching 96.34% versus 95.31% (HR: 0.64, 95% CI 0.29–1.42; P = 0.274).

Grade 3/4 adverse events occurred at similar frequencies overall (30% in the nab-paclitaxel arm vs 38% in the docetaxel arm). Common all-grade adverse events including neutropenia, nausea, and myalgia occurred at comparable rates, but grade 3/4 peripheral sensory neuropathy was documented exclusively among patients receiving nab-paclitaxel. No treatment-related mortality occurred during the study.