Sunil Verma, MD, professor and head of the Department of Oncology at the University of Calgary, medical director of the Tom Baker Cancer Centre, discusses immunotherapy in HER2-positive breast cancer.
The era of immunotherapy will enter breast cancer soon, says Verma. Results from the PANACEA trial of the combination of pembrolizumab (Keytruda) and trastuzumab (Herceptin) reached an objective response rate of 15.2% in patients with trastuzumab-resistant, PD-L1–positive, HER2-positive breast cancer. Verma says that trials such as this have shown that checkpoint inhibitors need to be given earlier in the course of treatment with an effective partner.
This has led to an interest in the first-line setting with a taxane, trastuzumab, and pertuzumab (Perjeta) with or without checkpoint inhibitors. Additionally, there is interest in testing immunotherapy combinations in the neoadjuvant setting. The goal in introducing checkpoint inhibitors is to move further away from treatment with chemotherapy, Verma says. Generally, it is thought that a chemotherapy backbone is necessary with checkpoint inhibitors in breast cancer. Verma suggests that in HER2-positive breast cancer, a HER2-targeted agent could serve as a backbone for checkpoint inhibition.