This is a Phase I, open-label, dose escalation and dose expansion study to Evaluate the Safety, Tolerability and Preliminary Efficacy of SG2918 in subjects with Advanced Malignant Tumors who are refractory or resistant to standard therapy, or without available standard or curative therapy.

The study consists of dose escalation and dose expansion, the dose escalation will be performed in a standard 3+3 manner at the dose of 0.1mg/kg、0.5mg/kg、1 mg/kg、1.5mg/kg、2 mg/kg、2.5mg/kg and 3 mg/kg, and the dose expansion will be done in specific tumor types. Patients enrolled in the study will receive SG2918 treatment every three weeks (Q3W), until disease progression, intolerable toxicity or others, whichever occurs first.

Inclusion Criteria:

1. Histologically or cytologically documented advanced malignant tumors that is refractory/relapsed to standard therapies;
2. Adequate organ function;
3. ECOG Performance Status score of 0 or 1;
4. Must have at least one measurable lesion according to RECIST Version1.1;
5. Toxicity caused by prior anti-tumor therapy recovered to Grade 0 to 1 (CTCAE 5.0);
6. Must have an effective contraception during the study, starting with the Screening Visit through 7 months after the last dose of study intervention.

Exclusion Criteria:

1. Has active central nervous system metastatic lesions;
2. Has Active autoimmune disease requiring systemic therapy within the past 2 years;
3. Has Grade 2 and above peripheral neuropathy;
4. Has an active infection requiring systemic therapy;
5. Has a history of any of the following cardiovascular conditions within 6 months of dosing: myocardial infarction, unstable angina, cerebrovascular accident, transient ischemic attack, coronary artery bypass graft, pulmonary embolism, etc; has New York Heart Association (NYHA) Class II and above congestive heart failure; LVEF<50%;
6. Has a history of hypertensive crisis or hypertensive encephalopathy; Uncontrolled hypertension though standard treatment within 14 days before the first dose (systolic blood pressure≥160 mmHg and/or diastolic blood pressure≥100mmHg);
7. Has known human immunodeficiency virus (HIV) and/or hepatitis B or C infections;
8. Has a history of potent CYP3A4 inhibitor with 2 weeks;
9. Has received systemic anticancer therapy, radiotherapy, or surgery within 4 weeks before the start of study treatment;
10. Have received previous treatment targeted LILRB4 or MMAE experiencing serious adverse events;
11. Have received previous immunotherapy experiencing serious adverse events that leading to permanent discontinuation;
12. Have received systemic corticosteroids (equivalent dose > 10 mg/day of prednisone) or other immunosuppressive drugs within 14 days prior to the first dose;
13. Has had a severe hypersensitivity reaction to treatment with a monoclonal antibody (mAB) and or any components of the study intervention;
14. Any live vaccine within 28 days prior to the first dose;
15. Has a history of interstitial lung disease or active pneumonia or tracheal fistula; uncontrolled pleural, abdominal and pericardial effusion;
16. Has a history of a second malignancy, unless potentially curative treatment has been completed with no evidence of malignancy for 2 year.