Benefit Mixed with Caution for Buparlisib.

Data from the BELLE-3 trial suggest that adding the investigational PI3K inhibitor buparlisib to endocrine therapy may improve outcomes for patients with hormone receptor-positive advanced breast cancer whose tumors become resistant to mTOR inhibition. However, experts remain concerned about a high rate of serious adverse events seen during the trial. ©2017 American Association for Cancer Research.