This trial is a multicenter, open-label, dose exploration and cohort expansion Phase II clinical study designed to evaluate the safety, immunogenicity, and preliminary efficacy of different dosing regimens of SYS6026 injection (hereinafter referred to as "SYS6026") combined with Enlonstobart in patients with unresectable locally advanced or metastatic solid tumors associated with HPV types 16 or 18. The study consists of two phases: dose exploration and cohort expansion.
Age ≥18 years;
Confirmation by the research center of HPV type 16 and/or 18 infection in tumor tissue;
Pathologically confirmed unresectable locally advanced or metastatic solid tumor;
ECOG PS score of 0-1;
Tumor tissue testing reveals co-infection with other high-risk HPV types;
Presence of two primary tumors (applicable only to Cohort 3); for patients not in Cohort 3, inclusion is permitted if they have two primary cancers that are unsuitable for surgery, have failed standard treatment, and are considered by investigators to benefit from this study;
Adverse reactions from prior antitumor therapy have not yet resolved to CTCAE Grade V5.0 level ≤1 (excluding alopecia or participants deemed clinically insignificant by investigators);
Participation in other clinical trials involving the study drug within 28 days prior to first administration/randomization, excluding observational (non-interventional) trials or follow-up phases of intervention trials;