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