Retrospective study of the efficacy and safety of neoadjuvant docetaxel, carboplatin, trastuzumab/pertuzumab (TCH-P) in nonmetastatic HER2-positive breast cancer

Background Pertuzumab is FDA approved in the preoperative setting in combination with trastuzumab and chemotherapy, in women with nonmetastatic HER2 +- breast cancer. The TRYPHAENA trial (n = 77) reported a pathologic complete response rate (pCR), i.e., ypT0ypN0, of 52 % in patients treated with neoadjuvant (docetaxel, carboplatin, trastuzumab, & pertuzumab) TCH-P. Aside from this study, there is limited information regarding the safety and efficacy of TCH-P in the neoadjuvant setting. Our goal was to evaluate the safety and efficacy of neoadjuvant TCH-P in a non-clinical trial setting. Materials and methods Cancer data registry was utilized to identify patients with HER2 + nonmetastatic breast cancer that received neoadjuvant TCH-P. pCR was defined as the absence of invasive or noninvasive cancer in breast and lymph nodes, i.e., ypT0ypN0. Results 70 patients with a median age of 52 years met our inclusion criteria. Clinical staging was I-8.5 %; II-68.5 %; and III-22.8 %. 60 % of patients had hormone receptor (HR)-positive tumors. 23 % (16/71) of patients required dose reduction for rash, diarrhea, neuropathy, or thrombocytopenia. Overall, no patients developed grade 3-4 left ventricular systolic dysfunction(LVSD); an asymptomatic reduction in LVEF of >10 % was observed in three patients. The overall observed pCR rate was 53 %. As expected, the pCR rate was higher in patients with HR-negative breast cancer than for patients with HR+ disease: 69 % (20/29) vs. 42 % (17/41), respectively. The axillary downstaging rate was approximately 53 % (19/36). Conclusion Neoadjuvant TCH-P, in a nonclinical trial setting, was associated with a pCR rate of 53 % similar the reported rate in TRYPHAENA. Toxicity was manageable, with no patients experiencing symptomatic heart failure.