Safety of everolimus plus exemestane in patients with hormone-receptor-positive, HER2-negative locally advanced or metastatic breast cancer: results of phase IIIb BALLET trial in Spain

Background Everolimus with exemestane has shown promising activity in patients with hormone-receptor (HR)-positive HER2-negative endocrine-resistant advanced breast cancer. It is necessary, therefore, to characterize the safety profile of this new combination in the real-world clinical setting and in the broadest possible population.