Utility of T-DM1 in Patients With HER2-Positive Breast Cancer

Alexandra Higgins, MD, a third year hematology-oncology fellow at Mayo Clinic, discusses when to use ado-trastuzumab emtansine (Kadcyla;T-DM1) in patients with HER2-positive breast cancer, and how to address particular adverse events that patients may develop while on treatment.

According to Higgins, T-DM1 therapy is typically given to patients who have residual disease after chemotherapy and HER2-directed therapy before surgery, and in the second line setting in metastatic disease.

Community oncologists should pay close attention to patients who have been on T-DM1 therapy for more than 1 to 2 years, according to Higgins. In a study of patients on T-DM1 therapy, some who developed respiratory toxicity were on treatment for at least 3 years.

0:08 | There are 2 clinical scenarios where we use T-DM1. One is for patients who have residual disease after getting chemotherapy and HER2-directed therapy before surgery, and then those with metastatic disease. Currently, that's in the second line setting, but that could be changing based on recent trials, and of course, data that we're going to hear this week.

0:28 | But I would say for the community oncologist, paying close attention to those women or men with metastatic HER2-positive breast cancer who had been on T-DM1 for more than 1 to 2 years. At least in our study, all of the patients who developed this had been exposed to T-DM1 for at least 3 years before developing the respiratory failure. So again, having a low threshold as a clinician to explore any complaints of dyspnea with exertion. So, even if your patient has normal oxygen levels sitting there in the clinic with you, even if their recent echocardiogram shows normal heart function, again, evaluating further with an arterial blood gas, a walk test, to look for hypoxemia, when they move their body, and then carefully reviewing their imaging for any evidence of liver disease are two important first steps. And if there's any concern based on either of those first steps to get a contrast echo, or a lung perfusion study to confirm that there is shunting of the blood in the lungs.