Ado-trastuzumab emtansin (T-DM1) may improve clinical response in patients with human epidermal growth factor receptor 2 (HER2)–positive, metastatic breast cancer, who have previously been treated with pertuzumab, according to a study published in the Journal of Clinical Oncology.1

Researchers analyzed data from 78 patients to determine whether T-DM1 is a viable treatment option for HER2-positive metastatic breast cancer patients who had received prior trastuzumab and pertuzumab, the latter of which is a standard initial therapy.

Slightly less than one-third of patients received T-DM1 as either a first or second-line therapy; 30.8% received T-DM1 for 6 months or longer (95% CI, 20.6%-41.1%); average tumor response rate was 17.9% (95% CI, 9.4%-26.4%).

Despite low tumor response rates, the fact that less than one-third of patients received T-DM1 for at least 6 months, and that in 94% of patients the drug was discontinued for either disease progression (84%), or toxicity (10%), the authors concluded that T-DM1 provides a clinical benefit to patients who had previously received pertuzumab.

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Patient records were obtained from databases at MD Anderson Cancer Center, Smilow Cancer Hospital at Yale, and The James Cancer Hospital at the Ohio State University.

Reference

1. Dzimitrowicz H, Berger M, Vargo C, Hood A, Abdelghany O, Raghavendra AS, et al. T-DM1 activity in metastatic human epidermal growth factor receptor 2–positive breast cancers that received prior therapy with trastuzumab and pertuzumab [published online ahead of print June 13, 2016]. J Clin Oncol. doi: 10.1200/JCO.2016.67.3624.