Inclusion Criteria:
* ECOG 0-1
* Histologically or cytologically confirmed diagnosis of endometrial cancer documented as TP53WT
* Subjects with advanced or recurrent disease must have completed a single line of up to 6 cycles of taxane-platinum based chemo and achieved a CR or PR per RECIST V1.1
* Adequate hematologic, hepatic and renal function (within 14 days)
Exclusion Criteria:
* Has any sarcomas or small-cell carcinomas with neuroendocrine differentiation
* Prior immune therapy, cytokine therapy, or any investigational therapy (within 28 days)
* Indwelling surgical drains
* Grade 2 or higher QTc prolongation
* History of major organ transplant
* History of bleeding diathesis; major hemorrhage or intracranial hemorrhage (within 24 weeks)
