On May 3, the U.S. Food and Drug Administration (FDA) approved ado-trastuzumab emtansine (T-DM1; Kadcyla) for the adjuvant treatment of patients with HER2-positive early breast cancer who have residual invasive disease after neoadjuvant taxane- and trastuzumab-based treatment.
Patients should be selected based on an FDA-approved companion diagnostic for T-DM1. The FDA also approved both the Ventana Medical Systems, Inc, PATHWAY anti-HER-2/neu (4B5) Rabbit Monoclonal Primary Antibody assay and the INFORM HER2 Dual ISH DNA Probe Cocktail assay as companion diagnostic devices for selecting patients.
Approval was based on the KATHERINE trial, a randomized, multicenter, open-label study of 1,486 patients with HER2-positive early breast cancer. See pages 26, 27, and 32 for a detailed report on the Katherine trial. ■