Inclusion Criteria:

• Must give written informed consent and any authorizations required by local law (e.g., Protected Health Information [PHI]).
• Females aged ≥18 years old at the time of informed consent.
• Advanced (Stage III or IV), histologically-documented epithelial ovarian cancer or primary peritoneal cancer (excluding small, round-cell histologies).
• Radiologically-documented evidence of progressive disease.
• Platinum-resistant disease defined as having a best response of SD or disease progression during or within 6 months of discontinuing a platinum-based chemotherapy (carboplatinum, cisplatinum, or another organoplatinum compound).
• Progression during or following treatment with topotecan or liposomal doxorubicin.
• Three or fewer prior chemotherapy regimens (including a platinum-based therapy).
• At least 1 measurable target lesion in accordance with RECIST criteria to assess clinical response (tumors within a previously irradiated field are designated as non-target).
• ECOG Performance Status ≤1.
• Life expectancy >12 weeks.
• Available paraffin block or unstained paraffin sections on glass slides containing representative tumor tissue from the most recent tumor biopsy/resection.
• Subjects of child-bearing potential must be willing to practice effective contraception during the study and be willing and able to continue contraception for at least 6 months after their last dose of study treatment (about 5 half lives).

Exclusion Criteria:

• Screening clinical laboratory values:

  • Absolute neutrophil count <1500/µL
  • Platelet count <75,000/µL
  • Hemoglobin <8.5 g/dL (hemoglobin may be supported by transfusion, erythropoietin, or other approved hematopoietic growth factors; darbopoeitin [Aranesp®] is permitted)
  • Serum bilirubin >2.0 x upper limit of normal (ULN)
  • AST and ALT >2.5 x ULN (AST and ALT >5 × ULN for subjects with liver metastasis)
  • Serum creatinine >2.0 mg/dL
  • International normalized ratio (INR) >1.5
  • Activated partial thromboplastin time (aPTT) >1.5 × ULN
• Clinically significant peripheral vascular disease.
• Non-epithelial ovarian tumors.
• Active infection requiring systemic antibiotics, antivirals, or antifungals including HIV/AIDS, hepatitis B, or hepatitis C infection.
• History of abdominal fistula, gastrointestinal (GI) perforation, or intra-abdominal abscess within 6 months prior to Day 1.
• Serious, non-healing wound, or bone fracture.
• Known central nervous system or brain metastases.
• History of uncontrolled psychiatric condition within 6 months prior to Day 1.
• History of other malignancies within 3 years of Day 1, except for adequately treated carcinoma in situ of the cervix, ductal carcinoma in situ (DCIS) of breast, or basal or squamous cell skin cancer.
• Evidence of autoimmune disease including, but not limited to, ulcerative colitis, Crohn's disease, rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) sceloderma, or another diseases in which immune function or immune competence is known to be impaired.
• Any history of lymphoproliferative disorder.
• Known human anti-murine antibody (HAMA) and/or human anti-chimeric antibody (HACA).
• Any medical condition that may be exacerbated by bleeding, including a known bleeding disorder such as a coagulation defect, thrombocytopenia, active gastric or duodenal ulcer, or history of GI bleeding.
• Significant hemoptysis within one year prior to Study Day 1.
• Any investigational, anti-cancer therapy within 6 weeks prior to Day 1.
• Any non-investigational, anti-cancer therapy within 4 weeks prior to Day 1.
• Prior treatment with anti-angiogenic agents.
• Subjects who require treatment with an anti-coagulant with the exception of low-dose Aspirin® (≤81 mg/day), warfarin (≤1 mg/day), or heparin for IV catheter patency.
• Subjects who are taking concomitant immunomodulatory agents including, but not limited to, interferons, interleukins, systemic steroids, cyclosporine, tacrolimus, calcineurin inhibitors, chronic low-dose methotrexate, or azathioprine. (The use of inhaled or intranasal steroids or oral steroids at a dose of ≤10 mg/day prednisone or its equivalent are permitted.)
• Active, unstable severe cardiovascular disease, including poorly controlled angina, congestive heart failure (CHF), arrhythmias, myocardial infarction (MI), cardiomyopathy, atrioventricular (AV) block, electrocardiogram (ECG) evidence of acute ischemia, or significant conduction abnormality.
• History of thromboembolic or cerebrovascular events, such as stroke, or transient ischemic attack (TIA). (Note: Prior history of deep vein thrombosis will not exclude subjects from participating in this study.)
• Pregnant (positive pregnancy test) or lactating.
• Inability to comply with study and follow-up procedures.
• Any condition that, in the opinion of the Investigator, makes the subject unsuitable for study participation.
• Known hypersensitivity to murine or chimeric antibodies.
• Major surgery within 4 weeks prior to Day 1.