A Study of CS23546 in Subjects With Advanced Tumors

This study is a single arm, open phase I trial, consisting of a dose escalation phase (single dose+multiple doses) and a dose expansion phase, accompanied by pharmacokinetic and pharmacokinetic studies. The first visit period (21 days) of single dose and multiple doses during the dose-increasing phase is the DLT observation period.

Key Inclusion Criteria:

• Male or female and ≥18 years of age on day of signing informed consent.
• Histologically or cytologically confirmed unresectable advanced recurrent/refractory solid tumor or lymphoma that is failure or or intolerant of all standard therapy or for which no standard therapy is available.
• Individuals are required to provide tumor tissue samples for prospective detection of Programmed cell death 1 ligand 1 (PD-L1) expression and/or Microsatellite instability (MSI) / the DNA mismatch repair (MMR) status. Subjects who cannot be provided during the dose escalation phase will be evaluated by the researchers and sponsors before deciding whether to enroll.
• Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1.
• Adequate organ function.
• Life expectancy ≥12 weeks.
• Dose expansion phase: Cohort 1, Subjects with urothelial carcinoma. Cohort 2, Subjects with Extranodal NK/T-cell lymphoma (NKTCL). Cohort 3, Subjects with soft tissue sarcoma. Cohort 4, Subjects with PD-L1 expression positive and/or microsatellite-instability-high (MSI-H) / mismatch-repair-deficient (dMMR) advanced solid tumors or lymphoma

Key Exclusion Criteria:

• Received anti-tumor therapy (including but not limited to chemotherapy, targeted therapy, anti angiogenic therapy, immunotherapy, cell therapy, radiotherapy, tumor embolization, etc.) or experimental drugs/devices that have not been approved for marketing within 28 days before the first medication.
• History of ≥ Grade 3 immune related Adverse Events (irAEs) or termination of treatment due to irAEs during prior treatment with Programmed death 1 (PD-1) /PD-L1 antibody.
• Active autoimmune diseases present during the screening period and systemic treatment was received within 2 years before the first medication. Individuals who only require hormone replacement therapy (such as thyroxine, insulin, or physiological corticosteroids used for adrenal or pituitary insufficiency) can be enrolled.
• Presence of central nervous system metastasis and/or meningeal metastasis.
• Dose expansion phase: Subjects with solid tumors or lymphoma who have previously received PD-L1 inhibitors and belong to primary resistance.