No significant changes in global longitudinal strain (GLS) or cardiac biomarkers occurred in patients with metastatic human epidermal growth factor receptor 2 (HER2)-positive breast cancer receiving paclitaxel plus trastuzumab and pertuzumab (THP), a study published in the journal The Oncologist has shown.1
Although dual anti-HER2 therapy with trastuzumab and pertuzumab in combination with taxane-based chemotherapy improves survival in patients with metastatic HER2-positive breast cancer, dual anti-HER2 blockade may increase the risk for cardiotoxicity. Therefore, researchers sought to conduct a preplanned safety analysis within a phase 2 trial of the chemoimmunotherapy combination.
For the study, researchers enrolled 69 patients with metastatic HER2-positive breast cancer who had received no more than 1 line of prior therapy. Participants were treated with paclitaxel 80 mg/m2 weekly plus trastuzumab 6 mg/kg (8 mg/kg loading dose) and pertuzumab 420 mg (840 mg loading dose) every 3 weeks. Researchers measured GLS every 3 months, and troponin-I (TnI) and brain natriuretic peptide (BNP) levels every 6 weeks.
Myocardial strain imaging and blood biomarkers were also evaluated because they have been proposed as adjuncts to left ventricular ejection fraction (LVEF) monitoring for the early detection of cardiotoxicity during cancer therapy.
Results showed that after a median follow-up of 21 months, no patients had developed symptomatic heart failure; however, 2 patients experienced asymptomatic LVEF decline. Researchers observed no decline in average GLS over the 12 months and elevated cardiac biomarkers were not associated with LVEF decline.
These results ultimately further support the cardiac safety of dual anti-HER2 blockade previously reported in the CLEOPATRA trial and suggest that intensive cardiac monitoring may not be necessary.
1. Yu AF, Manrique C, Pun S, et al. Cardiac safety of paclitaxel plus trastuzumab and pertuzumab in patients With HER2-positive metastatic breast cancer [published online ahead of print March 16, 2016]. Oncologist. doi:10.1634/theoncologist.2015-0321.