Inclusion Criteria:
* Patients with advanced solid tumors who have failed standard therapy or for whom no standard therapy is available.
* Patients whose tumors are assessed as FAP-positive (high FAP expression with SUVmax uptake above liver background) by FAP-targeted diagnostic PET/CT imaging.
* In the investigator's judgment, no other treatment option with curative or life-prolonging potential is available.
* Male or non-pregnant, non-lactating females, aged ≥18 years.
* Eastern Cooperative Oncology Group (ECOG) performance status score ≤2.
* Life expectancy \>6 months.
* Female patients: Women of childbearing potential must agree to use highly effective contraceptive methods from screening until 6 months after the last dose of study drug.
* Male patients: Subjects must use a condom during sexual intercourse during the study and for 14 weeks after the last study treatment to prevent partner pregnancy and to avoid transmission of the study drug via semen; in addition, subjects should refrain from sperm donation during treatment and for 6 months after the last study drug administration.
* Subjects must provide written informed consent voluntarily before participation in the trial.
* Willing and able to comply with scheduled visits, treatment plans, laboratory tests, and other study procedures.
Exclusion Criteria:
* Clinically symptomatic central nervous system metastases or meningeal metastases, or other evidence that the patient's central nervous system or meningeal metastases are not controlled, and deemed unsuitable for enrollment by the investigator.
* Major organ surgery (excluding needle biopsy) or significant trauma within 4 weeks prior to the first use of study drug, or need for elective surgery during the study period.
* History of immunodeficiency, including positive HIV test, or other acquired or congenital immunodeficiency diseases, or history of organ transplantation, or severe autoimmune disease history deemed unsuitable for enrollment by the investigator; or allogeneic organ transplantation requiring immunosuppressive therapy.
* Receipt of systemic or local radioisotope therapy within 3 months prior to the first dose.
* Receipt of other investigational drugs not yet marketed within 4 weeks prior to the first use of study drug, or within five half-lives of the other investigational drug.
* Definitive history of neurological or psychiatric disorders, including epilepsy or dementia.
* Pregnancy or lactation, or unwillingness to use adequate contraceptive methods.
* Any severe concomitant disease that, in the investigator's opinion, would make the patient's participation in the study inadvisable or could affect compliance with the protoco.
