The assessment of dual human epidermal growth factor receptor 2 (HER2) blockade has produced encouraging results in respect to HER2-overexpressing metastatic breast cancer.
Researchers conducted a retrospective analysis of data from 2 cancer centers that looked at the effect of trastuzumab plus lapatinib in patients with HER2-overexpressing metastatic breast cancer. The primary endpoints of the analysis were objective response rate and toxicity; secondary endpoints were progression-free survival and overall survival.
The analysis included data from 23 patients with HER2-positive metastatic breast cancer who had previously received trastuzumab and then received therapy that included both trastuzumab and lapatinib. The dual HER2 blockade treatment also included an addition of chemotherapy in 13 (56%) of the patients who were analyzed. Another 8 patients (35%) were also treated with hormonotherapy and 2 patients (9%) received only trastuzumab and lapatinib.
The overall response rate was 22% (5 patients) and 39% (9 patients) of patients had stable disease. Progression-free survival among patients being studied overall was 4 months.
The patients who received additional chemotherapy had progression-free survival of 5 months and patients who received hormonotherapy had 2 months of progression-free survival. Some patients experience grade 3 or higher adverse events which included diarrhea (26%) and hand and foot syndrome (9%).
The researchers concluded that, based on these retrospective findings, dual HER2 blockade combined with chemotherapy is a feasible treatment in patients with HER2-positive metastatic breast cancer who have already received trastuzumab treatment.
Dual human epidermal growth factor receptor 2 (HER2) blockade has been preclinically and clinically assessed in HER2-overexpressing metastatic breast cancer (mBC) with encouraging results. The findings suggest that dual HER2 blockade in combination with CT is feasible in pretreated HER2-positive mBC patients.