Apatinib Combined With Liposomal Irinotecan for Refractory or Metastatic Osteosarcoma

Prior treatment

• Prior treatment with apatinib.
• Prior use of irinotecan or other analogues of topoisomerase inhibitors.
• Within 3 weeks after the last dose of any prior therapy, including systemic cytotoxic drug therapy, targeted therapy, radiotherapy, immunotherapy, or any other investigational therapy.
• Patients with symptomatic serous cavity effusions (e.g., pleural effusion, ascites, or pericardial effusion) requiring surgical intervention.
• Participation in clinical trials of other antitumor drugs within the 4 weeks prior to enrollment.
• Treatment with strong CYP3A4 inhibitors within 7 days prior to study participation, or treatment with strong CYP3A4 inducers within 12 days prior to study participation.
• Patients currently receiving concurrent antitumor therapy.
• Patients with target lesions having previously received radiotherapy, but without subsequent progression.
• Patients who have received any vaccination during the treatment period, or have received an adenovirus-based vaccine within 4 weeks.

Other illness

• Known allergic reactions, hypersensitivity, or intolerance to apatinib, liposomal irinotecan, or any of their excipients.
• Patients with known brain metastasis, spinal cord compression, carcinomatous meningitis, or those with imaging evidence of leptomeningeal disease or unstable brain lesions detected by CT or MRI during screening.
• Uncontrolled hypertension (systolic blood pressure ≥140 mmHg or diastolic blood pressure ≥90 mmHg despite optimal medical therapy).
• Other poorly controlled diseases.
• Any condition that, in the investigator's judgment, may compromise the subject's well-being or ability to comply with or fulfill the study requirements.

Age

• Diagnosis of other malignancies within the past 3 years, except for adequately treated cutaneous basal cell carcinoma, carcinoma in situ of the cervix, or breast cancer that has undergone radical resection and remained disease-free for \>3 years.

Other

• Lactating women.

• The subject or their legal representative must sign a written informed consent form prior to enrollment.
• Diagnosis of refractory osteosarcoma confirmed by histopathology. Pathological confirmation is mandatory for localized tumors and isolated pulmonary lesions; it is not required for multiple pulmonary metastases.
• Disease progression after standard, adequate first-line and second-line chemotherapy regimens for osteosarcoma, or progression within 6 months of stopping such therapy.
• At least one measurable target lesion according to RECIST version 1.1 criteria.
• ECOG Performance Status score of 0 or 1, with an expected survival of ≥3 months.
• Recovery from prior therapies: all side effects (except alopecia) must have resolved to Grade 1 or lower per NCI-CTCAE version 5.0.
• Adequate organ function as indicated by the following peripheral blood counts and serum biochemistry results
• Women of childbearing potential must agree to use effective contraception (e.g., intrauterine device, oral contraceptives, or condoms) during the study and for 6 months after study completion; they must have a negative serum or urine pregnancy test within 7 days prior to study enrollment and must not be breastfeeding. Male participants must agree to use effective contraception or have undergone surgical sterilization during the study and for 6 months after its completion.