Neoadjuvant Nab-Paclitaxel May Not Improve pCR Rate vs Paclitaxel in Breast Cancer

In the neoadjuvant setting, nab-paclitaxel did not improve the pathological complete remission (pCR) rate compared with paclitaxel among women with ERBB2/HER2-negative breast cancer, according to a study published in JAMA Oncology.¹

For the open-label phase 3 ETNA study (ClinicalTrials.gov Identifier: NCT01822314), researchers randomly assigned 695 patients with newly diagnosed ERBB2/HER2-negative breast cancer to receive paclitaxel 90 mg/m² or nab-paclitaxel 125 mg/m² for 4 cycles prior to 4 weeks of investigator’s choice of anthracycline.

While patients treated with nab-paclitaxel did have a marginally higher pCR rate (22.5% vs 18.6% for paclitaxel), this improvement was not significant (odds ratio [OR], 0.77; 95% CI, 0.52-1.13; P = .19). Rather than choice of treatment, tumor subtype was the most significant factor in determining response to treatment (OR, 4.85; 95% CI, 3.28-7.18; P < .001). Triple-negative tumors responded especially well to treatment.

The adverse event (AE) rates were similar in the study arms: 94.9% and 95.5% of patients in the paclitaxel and the nab-paclitaxel arms, respectively, reported at least 1 drug-related AE, and 17.3% and 22.3% of patients, respectively, reported grade 3 or worse AEs.

The authors concluded that “the data do not show a different outcome of paclitaxel vs nab-paclitaxel in triple-negative or in [hormone receptor]-positive tumors selected to approximate the luminal-B subtype and do not support direct substitution of paclitaxel with nab-paclitaxel at the doses and schedule adopted in the ETNA trial.”

Reference

1. Gianni L, Mansutti M, Anton A, et al. Comparing neoadjuvant nab-paclitaxel vs paclitaxel both followed by anthracycline regimens in women with ERBB2/HER2-negative breast cancer-the evaluating treatment with neoadjuvant abraxane (ETNA) trial. JAMA Oncol. 2018 Jan 11. doi: 10.1001/jamaoncol.2017.4612 [Epub ahead of print]