QLC5508 vs. Chemotherapy in Pretreated Advanced or Metastatic Esophageal Squamous Cell Carcinoma

Exclusion Criteria

• •Diagnosis of other primary malignancies within 5 years prior to signing the informed consent form.
• •Having histologically or cytologically confirmed adenosquamous carcinoma subtype.
• •Brain metastases (unless asymptomatic and no progression confirmed by imaging ≥4 weeks prior to randomization);
• •Presence of leptomeningeal metastases or brainstem metastases;
• •Spinal cord compression (identified via imaging, regardless of symptoms);
• •Previous or ongoing treatment with topoisomerase I inhibitors
• •Having previously received B7-H3-targeted therapy.
• •Being ineligible to any chemotherapies in the control arm due to prior progression or intolerance.
• •Insufficient washout of prior anticancer therapies prior to randomization.
• •Having underwent major organ surgery (excluding biopsy) or significant trauma within 4 weeks prior to randomization;
• •Requiring elective surgery during the study.
• •Having received live vaccine or live attenuated vaccine within 4 weeks before study randomization.
• •Having received treatment with systemic corticosteroids (prednisone at \>10 mg/day, or similar drugs at equivalent dose) or other immunosuppressive agents within 14 days prior to randomization;
• •Moderate to severe pulmonary disease significantly impairing lung function, including idiopathic pulmonary fibrosis, autoimmune/connective tissue disorders with lung involvement, or prior pneumonectomy.
• •Having a history of interstitial lung disease (ILD)/ non-infectious pneumonitis that required corticosteroids, current ILD/ non-infectious pneumonitis, or suspected ILD/ non-infectious pneumonitis that cannot be ruled out by imaging at screening;
• •Active tuberculosis;
• •Autoimmune diseases not in clinical remission, other acquired or congenital immunodeficiency diseases,
• •A history of allogeneic stem cell, bone marrow, or organ transplantation.
• •Serious infections (e.g., bacteremia, or severe pneumonia) within 4 weeks prior to randomization;
• •active infection requiring systemic antibiotic therapy within 1 weeks prior to randomization;
• •Has positive results in virus serology tests (hepatitis B virus infection participants receiving antiviral treatment other than interferon are allowed to be enrolled);
• •Uncontrolled or significant cardiovascular disease.
• •Clinically uncontrolled third-space effusion.
• •Known hypersensitivity to investigational product components, analogues, or control drugs (e.g., docetaxel, paclitaxel, irinotecan hydrochloride).
• •Drug abuse;
• •Any other medical conditions that may interfere with study participation or the results of the clinical study as per the discretion of investigator;
• •Has alcohol or drug dependence.
• •Poor compliance as per investigator discretion;
• •Has a history of other serious systemic diseases.