Of note, the 33% of patients with human epidermal growth factor receptor 2 (HER2)-positive tumors also received trastuzumab 6 mg/kg (loading dose 8 mg/kg) and pertuzumab 420 mg (loading dose 840 mg) intravenously on day 1 every 3 weeks.

Results of the phase 3 trial showed that a pathologic complete response occurred in 38% (95% CI, 35 – 42) of patients who received nab-paclitaxel, compared with 29% (95% CI, 25 – 33) of those who received solvent-based paclitaxel (odds ratio, 1.53; 95% CI, 1.20 – 1.95; P = .00065).


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Subgroup analyses demonstrated that this improvement in response with nab-paclitaxel compared with paclitaxel was observed in the 23% of patients with triple-negative breast cancer (48% vs 26%; P = .00027).

“Based on the data, one could imagine that nab-paclitaxel would be the preferred taxane,” said Dr Loibl. “In fact, the majority of clinical trials investigating the new checkpoint inhibitors use nab-paclitaxel as the backbone taxane.”

In terms of safety, grade 3 to 4 anemia occurred in 2% of the 605 patients treated with nab-paclitaxel, compared with 1% of those treated with solvent-based paclitaxel (P = .048). In addition, grade 3 to 4 sensory neuropathy was significantly more common with nab-paclitaxel than paclitaxel (10% vs 3%; P < .001).

Researchers found that any-grade fatigue, diarrhea, rash, hand-foot syndrome, and neutropenia were also significantly associated with nab-paclitaxel treatment compared with paclitaxel.

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“The main question is, does this improvement in pathologic complete response translate into a longer disease-free and eventually overall survival?” Dr Loibl said. “We need to collect long-term outcome and follow-up data. It would also be good to have a confirmatory trial.”

Reference

  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.
  2. Abraxane (paclitaxel protein-bound) [prescribing information]. Summit, NJ: Celgene Corporation; July 2015. http://www.abraxane.com/wp-content/uploads/Abraxane_Prescribing_Information.pdf. Accessed February 22, 2016.