This single-arm, open-label, multicenter Phase II clinical study is divided into three phases: screening, treatment, and follow-up. The screening phase occurs within 28 days prior to the first administration of the study drug. During the treatment phase, a 28-day cycle is used, and tumor efficacy is assessed according to the RECIST 1.1 criteria. Assessments are conducted at the end of the first cycle (±3 days), followed by imaging evaluations every 8 weeks until disease progression. During the treatment period, the investigator may increase the number of assessments based on clinical needs. The study drug will be administered continuously until intolerable adverse reactions occur, disease progression, withdrawal of informed consent, loss to follow-up, death, or study termination.
The follow-up phase includes safety and survival follow-up. Safety follow-up occurs within 28 days after the last administration of the study drug. Survival follow-up is conducted every 12 weeks to collect the survival status of the subjects until their death, loss to follow-up, withdrawal from the study, or study termination (whichever occurs first).