Safety and Efficacy of Belzutifan in Preoperative Preparation for Patients With Pheochromocytoma/Paraganglioma (PPGL)

Prior treatment

• Receiving other anti-tumor drug therapies.
• A history of treatment with other HIF inhibitors.
• Prior receipt of chemotherapy, targeted therapy, biological agents, or other investigational treatments within the 4 weeks prior to the first administration of the study intervention.
• Occurrence of any of the following conditions within 6 months prior to study registration: Cerebrovascular Accident (CVA) or Transient Ischemic Attack (TIA); severe or unstable cardiac arrhythmia; pulmonary embolism or untreated Deep Venous Thrombosis (DVT).
• Concomitant use of drugs that interact with belzutifan.
• Resting pulse oximetry reading \< 92%, or requirement for intermittent oxygen supplementation, or long-term oxygen therapy.

Other illness

• A history of allergic reactions to belzutifan or hypoxia-inducible factor (HIF) inhibitors.
• Presence of multiple factors affecting oral drug administration (e.g., dysphagia, chronic diarrhea, intestinal obstruction, etc.) or other conditions interfering with medication intake.
• A history of seizures requiring medical treatment.
• A history of psychoactive substance abuse with inability to abstain, or presence of mental disorders.
• Patients with stable disease who decline surgical treatment.

Lab values

• Severe myelosuppression or coagulation abnormalities (International Normalized Ratio (INR) \> 1.5, or Prothrombin Time (PT) \> upper limit of normal (ULN) by 4 seconds, or Activated Partial Thromboplastin Time (APTT) \> 1.5 × ULN), a bleeding tendency, or ongoing thrombolytic or anticoagulant therapy.
• Active or uncontrolled comorbid diseases, including but not limited to:
  • Uncontrolled myocardial ischemia or myocardial infarction, cardiac arrhythmias (including corrected QT interval (QTc) \>= 480 ms), and uncontrolled congestive heart failure of New York Heart Association (NYHA) Grade \>= 2;
  • Clinically significant heart disease, including unstable angina pectoris, acute myocardial infarction, or a history of Coronary Artery Bypass Grafting (CABG) or Percutaneous Transluminal Coronary Angioplasty (PTCA) within 6 months prior to study enrollment, or congestive heart failure of NYHA Grade Ⅲ or Ⅳ;
  • Persistent or active infection;
  • Liver cirrhosis, decompensated liver disease, active hepatitis, or chronic hepatitis requiring antiviral therapy;
  • Renal failure requiring hemodialysis or peritoneal dialysis;
  • A history of immunodeficiency, including Human Immunodeficiency Virus (HIV) infection or other acquired/congenital immunodeficiency diseases, or a history of organ transplantation.

Age

• Pregnant or lactating women, and men or women of childbearing age who refuse to take appropriate contraceptive measures.

Other

• Incapable of correctly understanding the content of questionnaires and unable to cooperate with researchers.

• Aged 14 to 85 years.
• Adrenal pheochromocytoma or retroperitoneal paraganglioma suspected based on imaging and biochemical diagnoses.
• Scheduled for surgical treatment.
• American Society of Anesthesiologists (ASA) physical status classification of Grade Ⅰ to Ⅲ.
• Informed consent obtained from the patient or their legal guardian.
• Confirmed non-pregnant and non-lactating status.
• Laboratory requirements:
  • Absolute Granulocyte Count (AGC) \> 1.5 × 10⁹/L;
  • Platelet count \> 80 × 10⁹/L;
  • Hemoglobin (Hb) \> 90 g/L;
  • Serum bilirubin \< 1.5 × the upper limit of normal (ULN);
  • Serum creatinine \< 1.5 × ULN or creatinine clearance \>= 60 mL/min;
  • Negative serum human chorionic gonadotropin (hCG) test result.
• Capacity to understand the study and willingness to sign a written informed consent form.