ASCO 2017: Addition of Pembrolizumab to Standard Therapy in High-Risk Breast Cancer
Adding pembrolizumab to standard therapy improved pathologic complete response rates in patients with HER2-negative breast cancer, based on the results of the I-SPY 2 trial presented by Rita Nanda, MD, of the University of Chicago, at the 2017 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract 506). Dr. Nanda also discussed the findings in this subset of patients as well as the novel trial design of I-SPY 2 with William J. Gradishar, MD, of the Robert H. Lurie Comprehensive Cancer Center of Northwestern University, in a video recorded at the ASCO Meeting for JNCCN 360.
Dr. Nanda presented the findings of a high-risk subset of 69 patients with invasive breast cancer (≥ 2.5 cm by exam or ≥ 2 cm by imaging). They received weekly paclitaxel with and without the anti–programmed cell death protein 1 antibody pembrolizumab, followed by doxorubicin/cyclophosphamide. A total of 46 patients went on to surgery.
Pembrolizumab increased raw and estimated pathologic complete response rates in the 29 patients with triple-negative breast cancer by >50% and 40%, respectively, and in the 40 patients with hormone receptor–positive/HER2-negative disease by 13% and 21%, respectively. Five patients experienced immune-related grade 3 adverse events (one had hypophysitis and four had adrenal insufficiency).