A Multicenter, Randomized, Controlled Study of Telpegfilgrastim Versus Filgrastim for Secondary Prevention of Chemotherapy-Induced Neutropenia in Children and Adolescents With Solid Tumors Receiving High-Intensity Chemotherapy Regimens
The goal of this clinical trial is to evaluate the efficacy and safety of Telpegfilgrastim (a PEGylated recombinant human granulocyte colony-stimulating factor, PEG-rhG-CSF) compared to Filgrastim (short-acting rhG-CSF) in preventing chemotherapy-induced neutropenia (CIN) in children and adolescents aged 6-24 years with malignant solid tumors receiving high-intensity chemotherapy regimens. The main questions it aims to answer are: * Does Tuopefilgrastim reduce the incidence of febrile neutropenia (FN) in the first chemotherapy cycle (Cx+1) compared to Filgrastim? * How do the two treatments compare in terms of duration and severity of neutropenia, chemotherapy delays/dose reductions, antibiotic use, and bone pain incidence? Researchers will compare the Telpegfilgrastim group (3:1 ratio, 99 participants) with the Filgrastim group (33 participants) to determine if Telpegfilgrastim demonstrates superior efficacy and safety. Participants will: * Receive subcutaneous injections of either Telpegfilgrastim (33 μg/kg, single dose) or Filgrastim (5 μg/kg/day, multiple doses) 24 hours after each chemotherapy cycle. * Undergo blood tests, physical exams, and temperature monitoring during follow-up visits. * Be assessed for bone pain severity using age-appropriate scales (FLACC or Wong-Baker). * Complete two chemotherapy cycles with close safety and efficacy monitoring.
• Histologically or cytologically confirmed malignant solid tumor requiring high-intensity chemotherapy, with ≥2 remaining chemotherapy cycles, and either:
‣ Previous febrile neutropenia(FN) or dose-limiting neutropenia in the prior chemotherapy cycle without prophylactic granulocyte colony-stimulating factor (G-CSF);
⁃ Previous FN or dose-limiting neutropenia in the prior chemotherapy cycle despite prophylactic G-CSF.
• Age ≥6 to ≤24 years.
• Eastern Cooperative Oncology Group Performance Status ≤1.
• Normal bone marrow hematopoietic function: hemoglobin ≥75 g/L, white blood cell count ≥3.0×10\^9/L, platelets ≥80×10\^9/L, and neutrophils ≥1.5×10\^9/L.
• Anticipated survival ≥8 months.
• Willing to participate, with written informed consent signed by the patient or legal guardian.