Pragmatic Clinical Trial Assessing Response to Neoadjuvant Docetaxel and Trastuzumab in Nigerian Women With Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer (ARETTA).

PURPOSE: Breast cancer is the leading cause of death in Nigerian women. Clinical trials are required to provide evidence for treatment. We aimed to generate efficacy data to support the shift in local practice of neoadjuvant therapy for breast cancer.

METHODS

A one-stage, phase II feasibility, single-arm study design was used. Treatment-naïve patients with clinically nonmetastatic human epidermal growth factor receptor 2 (HER2)-positive breast cancer received four cycles of neoadjuvant docetaxel with subcutaneous trastuzumab (T + scH). Patients with complete clinical response underwent surgery. Patients with stable disease/partial response received three further cycles of 5-fluorouracil, epirubicin, and cyclophosphamide + scH before surgery. Responders completed 18 scH cycles. The primary end point was pathologic complete response (pCR). The secondary end points were toxicity and invasive disease-free survival.

RESULTS

A total of 53 female patients age 18-70 years were enrolled. The median age of the 47 evaluable female patients was 50 years. pCR was achieved in 25 of 47 patients (53% [95% CI, 38.1 to 67.9]; P < .001). Forty-two percent of patients were estrogen receptor+ and 40% were progesterone receptor+ (95% CI, 20.3 to 66.5 and 21.5 to 69.2, respectively). All were HER2+, with 40% stage II and 60% stage III disease. Three patients (6.4%) experienced grade 3 myelosuppression, one (2.1%) experienced grade 3 diarrhea, two (4.3%) had a grade 4 adverse event, and two developed hepatitis while on the study medications. The reporting of disease-free and overall survival awaits future analysis.

CONCLUSION

This phase II study showed that neoadjuvant chemotherapy with T + scH resulted in pCR of 53%, surpassing the planned cutoff for success of 40%. This is comparable with the rates and other efficacy end points that follow data from phase II international trials. This regimen may be useful in the absence of pertuzumab and warrants further investigation.