This is a phase II study. All patients are stage IV non-squamas non-small cell lung cancer(NSCLC) with malignant pleura effusion, Eastern Cooperative Oncology Group (ECOG) performance status 0-2. The purpose of this study is to evaluate the efficacy and safety of AK112 in combination with chemotherapy in patients with NSCLC with malignant pleura effusion.

Inclusion Criteria:

• 18 to 75 years old (at the time of inform consent obtained)；
• Have histologically- or cytologically-confirmed diagnosis of Stage IV non-squamas NSCLC；
• The presence of malignant pleural effusion (positive pleural effusion cytology or multiple pleural nodules or thickening with pleural effusion on CT imaging)；
• Driver gene mutation negative；
• Have a life expectancy of at least 3 months；
• Have an Eastern Cooperative Oncology Group (ECOG) performance status of 0-2；
• Has adequate organ function；
• Have measurable disease based on Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 assessed by investigator；
• Be able to provide formalin fixed, paraffin-embedded (FFPE) tumor tissue obtained from either a core or excisional tumor biopsy；
• All female and male 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；
• Be able and willing to provide written informed consent and to comply with all requirements of study participation (including all study procedures).

Exclusion Criteria:

• Histological or cytological pathology confirmed the presence of small cell carcinoma components, or the main component is squamous cell carcinoma；
• Active malignancies within the past 3 years, with the exception of tumors in this study and cured local tumors；
• Is currently participating in a study of an investigational agent or using an investigational device;
• Active autoimmune disease requiring systemic treatment within 2 years prior to the start of study treatment；
• Subjects who received any prior treatments targeting VEGFR;
• Has known active Hepatitis B (e.g., HBsAg reactive) or Hepatitis C (e.g., HCV RNA [qualitative] is detected);
• History of myocardial infarction, unstable angina, cardiac or other vascular stenting, angioplasty, or surgery within 12 months prior to day 1 of study treatment;
• Has undergone major surgery within 30 days prior to the first dose of study treatment;
• 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 NOTE: Subjects with vitiligo or resolved childhood asthma/atopy would be an exception to this rule. Subjects that require intermittent use of bronchodilators or local steroid injections would not be excluded from the study;
• Has received a live virus vaccine within 30 days prior to first dose of study treatment；