Purpose: To evaluate the combination of docetaxel, vinorelbine, and trastuzumab as neoadjuvant therapy for human epidermal growth factor receptor 2 (HER2)--overexpressing breast cancer.
Patients and methods: Patients with stage IIB or III breast cancer, including inflammatory disease, and HER2 overexpression (determined by fluorescent in situ hybridization) were treated with six cycles of docetaxel 60 mg/m2 and vinorelbine 45 mg/m2 administered every 14 days with granulocyte colony-stimulating factor and quinolone prophylaxis. Trastuzumab was administered as a 4 mg/kg loading dose followed by 2 mg/kg weekly for 12 weeks. The primary efficacy end point was pathologic complete response (pCR) in the breast.
Results: Of 31 enrolled patients, 68% had T3 or T4 tumors and 90% were clinically node positive. Twelve patients (39%; 95% CI, 21.6% to 55.9%) achieved pCR in the breast and lymph nodes and 14 patients (45%; 95% CI, 27.6% to 62.7%) achieved pCR in the breast alone, and 19 patients (61%; 95% CI, 44.1% to 78.4%) were node negative after neoadjuvant therapy. Clinical response was documented in 29 patients (94%; 95% CI, 78.6% to 99.2%) with 26 complete responses (84%; 95% CI, 70.9% to 96.8%). The most commonly reported grade 3/4 toxicities were neutropenia (97%), febrile neutropenia (22%), anemia (6%), mucositis/stomatitis (6%), constipation (6%), and skin rash (6%).
Conclusion: With clinical response and pCR rates of 94% and 39%, respectively, docetaxel, vinorelbine, and trastuzumab is a highly active neoadjuvant therapy for HER2-overexpressing locally advanced breast cancer. Although well tolerated overall, significant febrile neutropenia was observed despite prophylactic measures; therefore, evaluating a similar regimen using lower docetaxel and/or vinorelbine doses is warranted.