Pertuzumab (Perjeta) is a relatively new drug that targets HER2, a protein found at higher-than-normal levels in about 15% to 20% of all breast cancers. Too much HER2 leads to tumor growth. Currently, all newly diagnosed breast cancer patients have their tumors’ HER2 levels tested. Knowing whether a patient’s HER2 levels are abnormally high (HER2-positive) or normal (HER2-negative) is a major factor in choosing a treatment, thanks to the availability of trastuzumab (Herceptin) and, now, other HER2-targeted drugs such as Perjeta, T-DM1 (Kadcyla), and lapatinib (Tykerb). These drugs are all used to treat HER2-positive patients. Continue reading…
The gist: Before surgery to remove a tumor, breast cancer patients might take neoadjuvant therapy to shrink the tumor or otherwise help ensure a more successful surgery. A recent study concludes that combining two HER2-targeted drugs with chemotherapy might be the best neoadjuvant treatment choice for women with HER2-positive breast cancer. The researchers compared data from patients who received different combinations of chemotherapy, trastuzumab (Herceptin), and lapatinib (Tykerb). Patients who received all three had the highest chance of having no more signs of an invasive tumor after the treatment.
“For women with human epidermal growth factor receptor 2 (HER2)-positive breast cancer, combining two anti-HER2 agents with chemotherapy is the most effective treatment modality in the neoadjuvant setting, according to a meta-analysis published in the Journal of the National Cancer Institute.
“The study by Nagayama et al found that chemotherapy with trastuzumab (Herceptin) plus lapatinib (Tykerb), or with trastuzumab plus pertuzumab (Perjeta), resulted in a statistically significantly larger number of patients achieving pathologic complete response than did chemotherapy alone, chemotherapy with a single targeted therapy, or two anti-HER agents without chemotherapy. Ranking of treatment arms indicated that chemotherapy with trastuzumab plus pertuzumab “had the highest probability of being the best treatment arm in terms of [pathologic complete response],” the investigators stated.
“ ‘The growing number of HER2-targeted agents has created the need to define the optimal neoadjuvant therapy for HER2-positive breast cancer,’ the researchers wrote in explaining the rationale for the study. While other trials have been conducted to compare treatments, ‘it is difficult to integrate information on the relative efficacy of all tested regimens, since each trial has compared only a few treatments,’ the investigators noted.”