The Efficacy and Safety of Penpulimab in the Treatment of Metastatic PPGL Patients Who Fail to Other Systemic Treatment

Inclusion Criteria: Provide written informed consent. Age 18-75 years old Eastern Cooperative Oncology Group (ECOG) performance status 0, 1, or 2. Patients with histologically or radiologically confirmed MPP and fail to other systemic therapy. Estimated life expectancy longer than 6 months. Confirmed non-pregnancy and lactation. During the entire study period and within 6 months after the last administration, the subjects and their spouses are willing to use efficient contraceptive measures. Laboratory requirements: Absolute granulocyte count (AGC) greater than 1.5 x 109/L; Platelet count greater than 80 x 109/L; Hemoglobin greater than 90g/L; Serum bilirubin less than 1.5 x upper limit of normal (ULN); --)Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) less than 2.5 x ULN; Serum creatinine less than 1.5 x ULN or creatinine clearance (CCr)≥60ml/min; Doppler ultrasound assessment: left ventricular ejection fraction (LVEF) ≥ lower limit of normal value (50%). Exclusion Criteria: Patients who had been previously treated with anti-PD1, anti-PD-L1, or anti-PD-L2 medications were excluded from this trial. Has a diagnosis of immunodeficiency or is receiving systemic steroid therapy or any other form of immunosuppressive therapy within 14 days prior to the first dose of trial treatment. Has a known history of active TB (Bacillus Tuberculosis). Has a known history of Human Immunodeficiency Virus (HIV). Has known active Hepatitis B (e.g., HBsAg reactive) or Hepatitis C (e.g., HCV RNA [qualitative] is detected). Has an active infection requiring systemic therapy. Didn't meet eligibility for organ function. Abnormal coagulation (INR >1.5 or prothrombin time (PT) > ULN 4 seconds or APTT >1.5 ULN), bleeding tendency or being treated with thrombolytic or anticoagulant therapy. Uncontrolled congestive heart failure .