This study seeks to determine the effectiveness of Rucaparib as maintenance therapy for metastatic and recurrent endometrial cancer, after 1-2 prior lines of therapy.

This is a phase II clinical trial, that administers a maintenance treatment after first line chemotherapy is complete. It is designed to have a 1:1 randomization technique. Half the participants who enter the study will receive the active ingredient, Rucaparib, while the other half will receive a placebo. Treatment will be until progression with follow up until death.

Inclusion Criteria:

In order to be eligible to participate in this study, an individual must meet all of the following criteria:

1. Provision to sign and date the consent form.
2. Stated willingness to comply with all study procedures and be available for the duration of the study.
3. Be a female aged 18-89.
4. Patients with a primary Stage III/IV or recurrent endometrial cancer.
5. Patients have received at least one prior chemotherapy regimen and no more than two prior cytotoxic regimens (including hormonal therapy).
6. Primary chemotherapy regimen must have consisted of at least 4 completed cycles and no more than 8 completed cycles.
7. Previous cytotoxic regimen at least 4 weeks before initiation and no more than 8 weeks from initiation after last dose of previous therapy.
8. Patients who receive radiation to the whole pelvis or at least 50% of the spine must complete radiation therapy and have at least 4 weeks' time elapse prior to initiation of drug.
9. Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1 or 2.
10. Absolute neutrophil count (ANC) > or = 1500 cells/microliters
11. Platelet count > 100,000 microliters
12. Hemoglobin > or = 9.0 g/dL
13. Serum albumin > or = 2.5 g/dL
14. Total bilirubin ≤ 1.5 x ULN (uppler limit of normal)
15. AST and ALT ≤ 3.0 x ULN
16. Serum Creatinine ≤ 1.5x ULN

Exclusion Criteria:

An individual who meets any of the following criteria will be excluded from participation in this study:

1. Inability to comply with study and follow-up procedures
2. Significant cardiovascular disease, such as New York Heart Association cardiac disease (Class II or greater), myocardial infarction within the past 3 months, unstable arrhythmias, or unstable angina
3. Known clinically significant liver disease defined as AST and ALT > 3.0 x ULN and/or Total bilirubin > or = 1.5 x ULN, or documented history of active viral, alcoholic, or other hepatitis, cirrhosis, and inherited liver disease
4. Participation in investigational clinical trial within last 30 days
5. History of significant chronic disease including HIV/AIDS or hepatitis C
6. Inability to provide informed consent
7. Known central nervous system (CNS) malignancy or CNS metastases
8. Patients with previous malignancy, other than endometrial, within the past 2 years from cycle 1, day 1, with the exception of those with negligible risk of metastasis or death, such as adequately controlled basal cell carcinoma or squamous cell carcinoma of the skin or carcinoma in situ of the breast.
9. History of stroke or transient ischemic attack (TIA) within 3 months prior to cycle 1 day 1(C1D1)
10. Women with prognosis for survival less than 6 months
11. Patients who have progressed or have stable disease (SD) through most recent chemotherapy regimen
12. Patients deemed otherwise clinically unfit for clinical trial per Investigator's discretion
13. Patients with duodenal stent or other GI disorder/defect that would interfere with absorption of oral medication
14. Female patients who maintain fertility potential and refuse to comply to use contraception and be followed for pregnancy by pregnancy testing
15. Minor surgical procedure < or = 14 days or major surgeries < or = 28 days prior to first dose of treatment

4 years and 8 months.