A Study of AK112 Combined With PARP Inhibitor in the Treatment of Recurrent Ovarian Cancer

Inclusion Criteria: * Be able and willing to provide written informed consent. * ≥ 18 years old to ≤ 75 years old at study enrollment, female subjects. * Have an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1. * Have a life expectancy of at least 3 months. * Have histologically or cytologically diagnosis of epithelial ovarian, fallopian tube, or primary peritoneal carcinoma. * Have received at least two lines of platinum-containing treatment (bevacizumab or its biosimilars was allowed), and were platinum-sensitive recurrence (progression more than 6 months after the last dose of platinum-containing regimen). * Have measurable disease based on Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 assessed by investigator. * Be able to provide formalin fixed, paraffin-embedded (FFPE) tumor tissue. * Has adequate organ function. * All subjects of reproductive potential must agree to use an effective method of contraception, as determined by the Investigator, during and for 120 days after the last dose of study treatment. * Able to to comply with all requirements of study participation (including all study procedures). Exclusion Criteria: * Previous history (within five years) or concurrent malignant neoplasm, except that basal cell carcinoma and/or squamous cell carcinoma of the skin, superficial bladder cancer, cervical cancer in situ or breast cancer in situ that has undergone curative therapy. * Participation in a study of an investigational drug or using an investigational device within 4 weeks of first study drug administration. * Ovarian, fallopian tube or primary peritoneal cancer cancer of non-epithelial origin (such as germ cell carcinoma). * Previous targeted therapy using small molecules (except PARP inhibitors) and/or immunotherapy. * Have a potent or moderate CYP3A inhibitor, or a potent or moderate CYP3A inducer within 1 week prior to first study drug administration (or 5 drug half-lives, whichever is longer). * Has an active autoimmune disease that has required systemic treatment in the past 2 years (i.e. with use of disease modifying agents, corticosteroids or immunosuppressive drugs). Replacement therapy (e.g., thyroxine, insulin or physiologic corticosteroid replacement therapy for adrenal or pituitary insufficiency, etc.) is not considered a form of systemic treatment. * Active or previous history of inflammatory bowel disease such as Crohn's disease, ulcerative colitis or chronic diarrhea. * History of immunodeficiency and/or HIV antibody positive subjects. * Has severe infection 4 weeks prior to first study drug administration, including but not limited to complications requiring hospitalization, sepsis or severe pneumonia; active infection requiring systemic anti-infective therapy within 2 weeks prior to first study drug administration (excluding antiviral therapy for hepatitis B or C). * Has known active Hepatitis B that is untreated and requiring antiviral therapy during study period; or active Hepatitis C subjects (HCV antibody positive with HCV-RNA levels above the detection threshold). * Has undergone major surgery or severe trauma within 30 days prior to the first study drug administration. * Has known active central nervous system (CNS) metastases. * Uncontrolled co-morbidities including but not limited to symptomatic congestive heart failure (NYHA≥2), unstable angina, acute myocardial infarction, poorly controlled arrhythmias, decompensated cirrhosis, nephrotic syndrome, uncontrolled metabolic disorders, severe peptic ulcer disease or gastritis. * Uncontrolled hypertension despite optimal medical treatment; history of hypertensive crisis or hypertensive encephalopathy. * Any arterial thromboembolism, transient ischemic attack, cerebrovascular accident occurred within 6 months prior to the first study drug administration. * History of abdominal fistula or gastrointestinal perforation associated with anti-VEGF therapy; imaging results revealed invasion of the intestinal wall by tumor during screening. * Imaging or clinical findings of gastrointestinal obstruction, including incomplete obstruction. * Unable to swallow tablets or has had gastrointestinal abnormalities that may affect drug absorption as determined by the investigator. * Has had live vaccine within 30 days prior to first study drug administration or plan to receive live vaccine during the study period. * Has known psychiatric or substance abuse disorders, including alcohol or drug abuse. * Pregnant or lactating female subject. * Any prior or concurrent disease, treatment, or laboratory test abnormality that may confuse study results, affect subjects' full participation in the study, or may not be in their best interest to participate.