CDK4/CDK6 inhibitors will most likely not have a role as monotherapy, said Ingrid Mayer, MD, Associate Professor of Medicine, Division of Hematology/Oncology, Vanderbilt University Medical Center, Nashville, TN, who discussed the study results.
Five-year analysis of the phase 3 ALTTO trial showed no decided benefit to dual HER2 blockade over single-agent HER2-targeted therapy for the treatment of HER2-positive early-stage breast cancer. However, an indication for dual HER2 blockade use in HER2-positive, estrogen receptor–negative tumors is a possibility.
A modest reduction in the risk for invasive breast cancer was achieved by adding a second HER2-targeted agent to the treatment regimen for women with early-stage HER2+ breast cancer. The results suggest that the strategy may be appropriate in women at highest risk for recurrence.
A 9-week course of trastuzumab as adjuvant therapy in women with hormone receptor–positive, early-stage breast cancer can maintain efficacy and reduce toxicity compared with the standard 1-year course of trastuzumab.
The global phase 3 MONARCH 2 trial showed a significant advantage to adding the CDK4/6 inhibitor abemaciclib to fulvestrant in women with hormone receptor–positive, HER2-negative advanced breast cancer.