ASCO 2017: Dual HER2 Blockade in Metastatic Breast Cancer
The combination of two HER2-targeted therapies—lapatinib and trastuzumab—appears to offer a survival advantage to some women with HER2-positive, hormone receptor–positive metastatic breast cancer, according to the results of the phase III ALTERNATIVE trial. William J. Gradishar, MD, of the Robert H. Lurie Comprehensive Cancer Center of Northwestern University, presented these findings at the 2017 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract 1004).
The study enrolled 355 patients to 1 of three treatments: 117 received trastuzumab alone, 118 received lapatinib alone, and 120 received the combination of both agents. In patients receiving the combination therapy, trastuzumab alone, and lapatinib alone, the objective response rates were 32%, 14%, and 19%, respectively. Progression-free survival was longer in the combination therapy group than in the trastuzumab alone group (11 vs. 5.7 months).
Adverse events occurred more often with the combination treatment. The most common side effects with the combination of lapatinib and trastuzumab were diarrhea, rash, nausea, and paronychia.
The investigators concluded that dual HER2 blockade may “potentially offer an effective chemotherapy-sparing treatment option in the subgroup of HER2-positive, hormone receptor–positive patients with aggressive disease and who are not candidates for chemotherapy.”