Dr. Denise Yardley on PI3K Inhibitors

Denise Yardley, MD, senior investigator, breast cancer research, Sarah Cannon Research Institute discusses the phase II FERGI study and how it can be applied to more than just breast cancer.

The study compared PI3K inhibitor pictilisib to fulvestrant in patients with metastatic breast cancer. The PI3K pathway is evident in multiple tumor types and is linked to endocrine therapy resistance and HER2-targeted therapy resistance, says Yardley.

There was a signal of efficacy shown in the FERGI trial, however it may have been hampered somewhat by looking at the archival tissue that was on the primary. To overcome this, Yardley is now in the practice of re- biopsying tumors at every progression, to determine if there is a new resistance pathway. These practice may be difficult to duplicate in other tumor types, says Yardley, as not all disease in the metastasis setting is easily accessible to biopsying.