This is a multicenter, open-label, phase Ia study to evaluate the safety, tolerability and preliminary efficacy of ILB2109, a A2a receptor antagonist, in patients with locally advanced or metastatic solid malignancies.

This is a two-part study consists of dose escalation and dose expansion. The dose escalation part adopts a 3+3 protocol design and consists of 5 cohorts. Based on the data obtained from the escalation study, selected cohorts will be expanded to further investigate the safety and efficacy of the study drug. The escalation part consists of a single-dose cycle (Cycle 0) followed by multiple-dose cycles (Cycle 1 and above). Subjects will be assessed for safety and efficacy outcomes at pre-specified time points.

Inclusion Criteria:

• Histologically or cytological confirmed, solid, malignant tumor that is refractory to standard therapy or for which no standard of care regimen currently exists;
• At least one assessable tumor lesion according to RECIST v1.1 in dose escalation part of the study ; At least one measurable tumor lesion according to RECIST v1.1 in dose expansion part of the study;
• Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1;
• Major organ functions are normal, meets pre-specified lab requirements;
• Females of reproductive age must have a negative serological hCG test during the screening period;
• Subjects of reproductive age (both male and female) must agree to use contraceptive methods from signing Informed Consent to 90 days post the last dose;

Exclusion Criteria:

• Has received any investigational medicinal product or other systemic anticancer treatment within 4 weeks prior to the first dose of study treatment;
• Unable to take medication orally, or has impaired GI function;
• Has received systemic glucocorticoids (prednisone>10 mg/ day or an equivalent dose of another drug of the same class) or other immunosuppressants within 14 days prior to the first dose of study treatment;
• Has received live, attenuated vaccines within 4 weeks prior to the first dose of study treatment;
• Has active infection that requires intravenous anti-infective therapy;
• History of HIV infection, or other acquired, congenital immunodeficiency disease, or a history of organ transplantation;
• History of serious cardiovascular and cerebrovascular diseases;
• History of adverse effect from previous antineoplastic therapy that has not returned to CTCAE grade 5.0 ≤1;
• Cerebral parenchymal or meningeal metastasis;
• History of ≥ Grade 3 irAE or ≥ Grade 2 myocarditis from previous immune therapy;