A Phase I Study of RGT-264 in Subjects With Advanced Solid Tumors

Inclusion Criteria:

* Able to sign the ICF and agree to comply with the requirements of the study;
* Subjects with pathologically confirmed advanced solid tumors who have failed standard-of-care therapy, or have no standard-of-care therapy available, or are currently not eligible for standard-of-care therapy;
* ECOG performance status score of 0 to 1;
* Expected survival ≥ 3 months;
* With at least one measurable lesion per RECIST v1.1;
* Subjects should discontinue all anti-tumor therapies prior to receiving study treatment, and the toxicity caused by prior anti-tumor therapy has recovered to ≤ Grade 1 per CTCAE v5.0;
* The specific requirements of washout period should be met before first dose;
* Adequate organ function
* Female subjects of childbearing potential must have a negative pregnancy test prior to the first dose and are required to use effective contraception from signing the ICF until 6 months after the last dose of study treatment

Exclusion Criteria:

* Presence of risks that may significantly affect the absorption of the investigational product (e.g. inability to swallow, intestinal obstruction, chronic diarrhea, etc.);
* Having received immunotherapy and experienced ≥ Grade 3 immune-related adverse events (irAEs) or ≥ Grade 2 immune-related myocarditis;
* Having received systemic glucocorticoids (\> 10 mg/day of prednisone or equivalent) or other immunosuppressants within 14 days prior to the first dose of investigational product;
* Presence of symptomatic parenchymal brain metastasis or leptomeningeal metastasis;
* Active, or previous autoimmune disease with the potential for relapse (excluding well-controlled type 1 diabetes mellitus; manageable hypothyroidism with hormone replacement therapy only).;
* Any other malignancy (except cured basal cell carcinoma of skin and in-situ carcinoma of the cervix) within 3 years prior to the first dose;
* History of serious cardiovascular and cerebrovascular diseases;
* Presence of active interstitial lung disease or history of interstitial lung disease requiring glucocorticoid treatment;
* Presence of severe chronic or active infections (including tuberculosis infection, etc.) requiring intravenous antimicrobial, antifungal or antiviral therapy;
* Active HBV or HCV infection;
* History of immunodeficiency or organ transplantation;
* Presence of uncontrolled third spacing fluid;
* Concomitant diseases or any other conditions that may seriously jeopardize the subject's safety or affect the subject's completion of the study, at the discretion of the investigator.