A Phase I/II Study to Assess the Safety and Therapeutic Effect of INCB007839 in Combination With Trastuzumab and Vinorelbine in Patients With Metastatic HER2+ Breast Cancer.

Inclusion Criteria:

- Subject with diagnosis of metastatic (or locally recurrent-inoperable) breast cancer

- Subject with histological HER2+ status as determined by FISH with a gene
amplification score of ≥ 2.2

- Subject with availability of archival biopsy tissue from primary tumor or metastatic
lesions

- Subject with presence of measurable disease based on RECIST 1.1

- Subject who has received no more than three prior HER2-directed therapeutic regimens
for advanced breast cancer

Exclusion Criteria:

- Subject with Left ventricular ejection fraction (LVEF) below institutional normal
range

- Subject with metastasis to the central nervous system UNLESS asymptomatic and
clinically stable

- Subject with current active malignancy other than breast cancer

- Subject with prior history of other malignancy except for cancers from which the
patient is currently disease free

- Subject with significant renal or hepatic dysfunction

- Subject with history of venous or arterial thrombosis or risk factor for thrombosis
other than history of malignancy

- Subject with insufficient bone marrow function

- Subject with contraindication to vinorelbine, trastuzumab, aspirin and/or warfarin
therapy.

- Subject with current active bacterial, Hepatitis B or C, and/or HIV infections