Pertuzumab-Containing Neoadjuvant Regimens in HER2-Positive Breast Cancer
“Traditional neoadjuvant systemic chemotherapy plus dual HER2-targeted blockade (docetaxel, carboplatin, and trastuzumab plus pertuzumab) resulted in significantly more patients achieving a pathologic complete response than HER2-targeted chemotherapy plus HER2-targeted blockade [ado-trastuzumab emtansine plus pertuzumab],” declared Sara A. Hurvitz, MD, of the University of California Los Angeles Medical Center, and colleagues, based on the findings of the phase III KRISTINE trial published in The Lancet Oncology. However, neoadjuvant systemic chemotherapy plus dual HER2-targeted blockade was also associated with higher rates of grade 3 or 4 and serious adverse events.
In the open-label trial, researchers enrolled 444 patients from 68 oncology centers across the globe. Participants had centrally confirmed HER2-positive stage II or III operable breast cancer.
A total of 123 of the 221 patients (55.7%) treated with the docetaxel regimen had a pathologically complete response, compared with 99 of 223 patients (44.4%) treated with the ado-trastuzumab emtansine regimen. In addition, an exploratory multivariate analysis suggested the ado-trastuzumab emtansine regimen and a positive hormone receptor status were linked to a lower likelihood of pathologic complete response.
Fewer patients in the ado-trastuzumab emtansine group had grade 3 or 4 adverse events (13% vs. 64%) or a serious adverse event (5% vs. 29%). Decreased platelet count, fatigue, increased alanine transaminase levels, and hypokalemia were the most common grade 3 or 4 adverse events reported with the ado-trastuzumab emtansine regimen, whereas neutropenia, diarrhea, and febrile neutropenia were the most common grade 3 or 4 adverse events noted with the docetaxel regimen.