Prophylactic Nanocrystalline Megestrol Acetate Versus Placebo for Chemoradiotherapy-Related Anorexia in Nasopharyngeal Carcinoma

This phase III randomized, double-blind, placebo-controlled, multicenter trial compares the efficacy and safety of nanocrystalline megestrol acetate versus placebo in prevention and management of anorexia and weight loss associated with concurrent chemoradiotherapy (CCRT) in patients with locally advanced nasopharyngeal carcinoma (NPC). Eligible patients with newly diagnosed stage II-III NPC will be randomly assigned in a 1:1 ratio to receive either nanocrystalline megestrol acetate (5ml/day) or matching placebo for 11 weeks, in combination with standard CCRT. The study aims to evaluate whether nanocrystalline megestrol acetate can significantly reduce the proportion of patients experiencing clinically significant weight loss (>5% from baseline) at day 28 post-radiotherapy, and to assess its impact on appetite, quality of life, nutritional status, and survival outcomes.

Inclusion criteria

• Newly diagnosed, histologically or cytologically confirmed non-keratinizing nasopharyngeal carcinoma, clinical stage II-III according to the American Joint Committee on Cancer (AJCC) 9th edition staging system, and planned to receive concurrent chemoradiotherapy (CCRT).
• No prior radiotherapy to the primary tumor.
• Induction chemotherapy may be administered at the investigator's discretion according to local guidelines.
• Aged 18-70 years, male or female.
• Eastern Cooperative Oncology Group (ECOG) performance status of 0-1.
• Able to comply with the study procedures and voluntarily provide written informed consent.
• Adequate organ function, defined as follows:

• Hematologic function: neutrophil count ≥1.5 × 10⁹/L, hemoglobin ≥90 g/L, and platelet count ≥100 × 10⁹/L.
• Coagulation function: international normalized ratio (INR), prothrombin time (PT), or activated partial thromboplastin time (aPTT) ≤1.5 × the upper limit of normal (ULN).
• Hepatic function: alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤2.5 × ULN, total bilirubin ≤2.0 × ULN, and serum albumin ≥30 g/L.
• Renal function: serum creatinine ≤1.5 × ULN or calculated creatinine clearance (CrCl) ≥60 mL/min using the Cockcroft-Gault formula.

Exclusion criteria

• Prior antitumor therapy, including chemotherapy, radiotherapy, or surgery, other than induction chemotherapy permitted according to the study protocol.
• Pregnant or breastfeeding women.
• Inability to comply with regular follow-up because of psychological, social, familial, or geographical factors.
• Concurrent participation in another clinical study involving investigational treatment during the study treatment period.
• Known allergy to any chemotherapeutic agent that may be used in the study.
• Severe uncontrolled infection or other serious uncontrolled medical illness.
• Major organ dysfunction, including decompensated cardiac, pulmonary, renal, or hepatic failure, that would preclude tolerance of chemoradiotherapy.
• Conditions that may substantially affect drug administration, distribution, metabolism, or excretion, including significant psychiatric disorders, central nervous system disorders, chronic diarrhea, ascites, or pleural effusion.
• Long-term use of immunosuppressive agents following organ transplantation.
• History of another malignancy before enrollment.
• Conditions affecting gastrointestinal absorption or oral intake, including dysphagia, malabsorption, or uncontrolled vomiting; difficulty with food intake or requirement for enteral or parenteral nutritional support; anorexia nervosa or anorexia related to psychiatric illness; or difficulty eating because of pain.
• Current or planned use of other medications that may increase appetite or body weight, including systemic corticosteroids (except short-term dexamethasone administered during chemotherapy), androgens, progestogens, thalidomide, olanzapine, anamorelin, or other appetite stimulants.
• Cushing syndrome, adrenal insufficiency, or pituitary insufficiency; poorly controlled diabetes mellitus; or uncontrolled hypertension, defined as systolic blood pressure ≥160 mmHg or diastolic blood pressure ≥100 mmHg despite oral antihypertensive therapy.
• Thromboembolic disease, ascites, or lower-extremity edema within 6 months before the first dose of study treatment; history of esophageal or gastric varices, severe gastrointestinal ulceration, gastrointestinal perforation and/or fistula, gastrointestinal obstruction (including incomplete intestinal obstruction requiring parenteral nutrition), intra-abdominal abscess, or acute gastrointestinal bleeding.
• Known hypersensitivity to any component of the study drug.
• Any other condition that, in the investigator's judgment, would make the patient unsuitable for participation in the study.