A Phase 1 Study of HCB303 in Participants With Advanced Malignancies

A Phase 1, Open-label, Multi-regional, Multicenter, Dose escalation Study to Evaluate the Safety, Tolerability, Pharmacokinetics, Pharmacodynamics, Immunogenicity, and Preliminary Antitumor Activity of HCB303 in Participants with Advanced Malignancies

Inclusion Criteria: 1. The participant is able to understand and willing to provide signed informed consent, including compliance with the requirements and restrictions described in the ICF and protocol. 2. Male or female participant ≥18 years of age at the time of signing the ICF. 3. Histologically or cytologically confirmed advanced solid tumor with relapsed, refractory, or progressive disease and no available standard therapy known to provide clinical benefit. 4. At least 1 measurable lesion per RECIST v1.1, as assessed by the Investigator. 5. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 at Screening. 5\. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 at Screening. 6\. Estimated life expectancy ≥12 weeks, in the judgment of the Investigator. Exclusion Criteria: Tumor-Related Medical Conditions 1. Other malignancies requiring treatment within 2 years before the first dose of HCB303, except for adequately treated locally curable malignancies, such as basal cell or squamous cell skin cancer, or other malignancies treated with no relapse within 2 years. 2. Primary central nervous system (CNS) tumor, active or untreated CNS metastases, or carcinomatous meningitis. Participants with previously treated brain metastases may participate if clinically stable for at least 28 days, have no evidence of new or enlarging brain metastases, and do not require high-dose corticosteroids within 14 days before the first dose of HCB303. Participants receiving low-dose corticosteroids, defined as \