Commenting on the I-SPY 2 neratinib results presented at the 2014 American Association for Cancer Research Annual Meeting, Edith Perez, MD, Deputy Director at Large, Mayo Clinic Comprehensive Cancer Center, Jacksonville, Florida, said that results were consistent with other data. “Testing for HER2 is important. These data corroborate that there is a higher chance of response [to neratinib] in the neoadjuvant setting in patients with estrogen receptor–negative breast cancer,” she said.

The issue of toxicity with neratinib is of concern, Dr. Perez continued. “There is a very high degree of diarrhea with paclitaxel/neratinib, and this will make it difficult for this regimen to compete with other HER2-directed agents like lapatinib [Tykerb],” she said. “In spite of prophylaxis, a significant number of patients still suffered from grade 3 diarrhea, consistent with at least seven episodes in a day or need for intravenous fluids for ≥ 24 hours.”

“It is important to conduct these types of trials,” she said. “It would also be important to look at subsets of patients with brain metastases to see if these drugs are of benefit. Another interesting triplet to study in phase III would be pertuzumab [Perjeta], trastuzumab, and neratinib.” ■

Disclosure: Dr. Perez has received research funding from Genentech and GlaxoSmithKline.