Aberrations in the PI3K signaling pathway are frequently observed in patients with breast cancer. Because of that, PI3K inhibitors are attractive options for the treatment of breast cancer because PI3K is the most proximal component of the pathway other than receptor tyrosine kinases. Buparlisib is a potent and highly specific oral pan-class I PI3K inhibitor, which is currently under investigation in patients with breast cancer. In this article, we describe the PI3K signaling pathway, the prognostic value of PI3K pathway mutations, as well as the mechanism of action of buparlisib. Lastly, we discuss preliminary results of preclinical and clinical studies showing the efficacy and safety profile of this agent in breast cancer patients.
Keywords: Breast cancer; Buparlisib; PI3K inhibitor; PI3KCA; Targeted therapy.