The purpose of this study is to evaluate the safety, tolerability and preliminary efficacy of elacestrant (RAD1901) in patients with advanced ER+, HER2-negative breast cancer.
To evaluate the efficacy of idasanutlin monotherapy in patients without prior ruxolitinib exposure with hydroxyurea (HU)-resistant/intolerant PV:
for patients with splenomegaly at baseline using composite response criteria (hematocrit [Hct] control without phlebotomy and 35% decrease in spleen size by imaging) at Week 32
for patients without splenomegaly at baseline by Hct control without phlebotomy only at Week 32
This study is being done to look at whether an agent that is commonly used to treat diabetes, Metformin, can decrease or affect the ability of breast cancer cells to grow and whether Metformin will work with another therapy to keep cancer from returning (recurring).