A Study of IBI3004 in Subjects With Unresectable, Locally Advanced or Metastatic Solid Tumors

1. Subjects have the ability to understand and give written informed consent for participation in this trial, including all evaluations and procedures as specified by this protocol;
2. Male or female subjects ≥ 18 years old. For Part 1, age ≥18 and ≤75 years old
3. Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 or 1;
4. Anticipated life expectancy of ≥ 12 weeks;
5. Adequate bone marrow and organ function

Exclusion Criteria:

1. Enrolled in any other interventional clinical research except unless only involved in an observational study (non-interventional) or in the follow-up phase of an interventional study;
2. Received previous anti-tumor therapy: within 21 days of monoclonal antibodies or cytotoxic therapy prior to the first dose of the study drug, or within 14 days of small molecule targeted drugs prior to the first dose of the study drug. Received palliative radiation therapy within 2 weeks prior to the first dose of the study drug, or received radical radiation therapy within 4 weeks prior to the first dose of the study drug;
3. Received live vaccines within 4 weeks prior to first administration of the study drug or plan on receiving any live vaccine during the study;
4. Has adverse reactions resulting from previous antitumor therapies, which have not resolved to Grade 0 or 1 toxicity according to NCI-Common Terminology Criteria for Adverse Events (CTCAE) v5.0 (except for alopecia, fatigue, pigmentation and other conditions with no safety risk according to investigator' discretion) or baseline prior to the first dose of the study drug;
5. Undergone major surgery (Craniotomy, thoracotomy or laparotomy, and other surgery according to investigator' discretion, excluding needle biopsy) within 4 weeks prior to the first dose of the study drug, or who are expected to undergo major surgery during the study period, or who have severe unhealed wounds, trauma, ulcers, etc.