Immunotherapy Rechallenge in Patients with Solid Tumors in Clinical Trials

This study plans to include approximately 60-100 patients with advanced solid tumors who have progressed on clinical trial drugs, using an open-label, single-arm, multi-cohort umbrella design. In the first phase, patients who have progressed during treatment with novel tumor immunotherapy drugs will initially be targeted, combining or sequencing with PD-1 monoclonal antibody therapy. The selection criteria for frontline clinical trials are as follows: priority will be given to phase I clinical trials of novel immunotherapeutics as monotherapy, such as tumor vaccines, NK cell therapy, and new immune checkpoint inhibitors. Based on preliminary data, these have shown synergistic effects with PD-1/L1 monoclonal antibodies. In principle, the same investigational drug will only be used in either a combination or sequencing cohort. Subsequently, the study will expand to include patients who have progressed on other clinical trial treatments, combining or sequencing with other immune mechanism drugs.

Based on the interventions, the study is divided into combination therapy cohorts, sequential therapy cohorts, and real-world cohorts. The combination therapy cohorts will be further subdivided according to the investigational drug the patients received in the frontline setting: for instance, patients who have progressed on investigational drug A (e.g., SG1827) will receive drug A combined with PD-1 monoclonal antibody therapy (cohort A), and patients who have progressed on investigational drug B (e.g., ABO2011) will receive drug B combined with PD-1 monoclonal antibody therapy (cohort B), and so on. In the sequential therapy cohorts, regardless of the investigational drug used in the frontline setting, patients will receive PD-1 monoclonal antibody therapy. The real-world cohorts will include patients who do not meet the inclusion criteria for the aforementioned cohorts or refuse to participate in the interventional trials, with only subsequent treatment information, tumor progression, and overall survival being collected.

No specific sample size is predetermined for each cohort, and the study team may adjust the cohort sizes based on preliminary study results. In the combination therapy cohorts, the dosage and administration method of the investigational drugs will continue as per the patients' previous trial treatments. In both the combination and sequential therapy cohorts, the PD-1 monoclonal antibody will be administered at a fixed dose of 200 mg every 21 days or 3 mg/kg every 14 days. The treatments will continue until disease progression, death, or the occurrence of intolerable toxicity.