Open Label Trial of INCB07839 to Determine Effect and Safety of INCB007839 Plus Trastuzumab in HER2 Positive Metastatic Breast Cancer

100 mg BID

200 mg BID

300 mg BID

300 mg BID

trastuzumab will be administered at a loading dose of 8 mg/kg as a 90 minute intravenous infusion on Day 8. In all subsequent 21-day cycles, trastuzumab will be administered at 6 mg/kg as a 90 minute intravenous infusion on Day 1.