A Study To Assess The Tolerability And Clinical Activity Of Gedatolisib In Combination With Palbociclib/Letrozole Or Palbociclib/Fulvestrant In Women With Metastatic Breast Cancer

This is a multicenter, open label, continuous Phase 1b study in patients with MBC. This study will have a dose escalation and expansion. The dose escalation will identify the maximum tolerated dose (MTD) of the combination of gedatolisib plus palbociclib/fulvestrant and gedatolisib plus palbociclib/letrozole. The expansion will estimate the objective response rate (OR) of the combination of gedatolisib plus palbociclib/letrozole and the combination of gedatolisib plus palbociclib/fulvestrant.