Nab-paclitaxel Increases Complete Response Rate in Invasive Breast Cancer
Replacing paclitaxel with nab-paclitaxel, followed by neoadjuvant epirubicin and cyclophosphamide significantly improved the number of patients with primary invasive breast cancer achieving a pathological complete response, a study published in the journal The Lancet Oncology has shown.1
Because nab-paclitaxel has demonstrated significantly increased progression-free survival compared with paclitaxel in metastatic breast cancer, researchers sought to determine whether weekly protein-bound nab-paclitaxel could increase the proportion of patients achieving a pathological complete response compared with weekly solvent-based paclitaxel.
For the phase 3 study, researchers enrolled 1206 women with previously untreated unilateral or bilateral primary invasive breast cancer and randomly assigned them to receive 12 weeks of intravenous nab-paclitaxel 125 mg/m2 to 150 mg/m2 on days 1, 8, and 15 for 4 21-day cycles, or intravenous paclitaxel 80 mg/m2 in the same fashion. All participants then received epirubicin plus cyclophosphamide intravenously on day 1 for 4 21-day cycles, in addition to trastuzumab and pertuzumab if patients had human epidermal growth factor receptor 2 (HER2)-positive tumors.
Results showed that the pathological complete response rate was 38% (95% CI: 35-42) in the nab-paclitaxel group compared with 29% (95% CI: 25-33) in the paclitaxel group (OR, 1.53; 95% CI: 1.20-1.95; P = .00065).
In terms of safety, the incidence of grade 3 or 4 anemia and peripheral sensory neuropathy was significantly higher for nab-paclitaxel than paclitaxel (P = .048 and P < .001, respectively). Serious adverse events occurred in 26% and 21% of the nab-paclitaxel and solvent-based paclitaxel arm, respectively (P = .057). Of note, 3 deaths occurred during the epirubicin and cyclophosphamide regimen in the nab-paclitaxel group compared with 1 death in the paclitaxel group.
“These results might lead to an exchange of the preferred taxane, solvent-based paclitaxel, for nab-paclitaxel in therapy for primary breast cancer,” the authors concluded.
1. Untch M, Jackisch C, Schneeweiss A, et al. Nab-paclitaxel versus solvent-based paclitaxel in neoadjuvant chemotherapy for early breast cancer (GeparSepto—GBG 69): a randomised, phase 3 trial [published online ahead of print February 8, 2016]. Lancet Oncol. doi: 10.1016/S1470-2045(15)00542-2.