This is an open-label, multicenter Phase Ib study to evaluate the safety, tolerability, and efficacy of IBI363 in advanced malignancies patients

Inclusion Criteria:

1. Sign written informed consent and be able to comply with the program's visit schedule and related procedures.
2. Male or female subjects, age 18~75 years.
3. Histologically or cytologically confirmed advanced malignancy.
4. Subjects who have progressed on standard therapy, who are unsuitable for standard therapy, who do not have standard therapy, or who have refused standard therapy. For particular cohort, subjects who have not received prior systemic therapy for advanced disease.
5. At least one measurable lesion (target lesion) per RECIST v1.1.
6. Eastern Cooperative Oncology Group Performance Status (ECOG PS) of 0 or 1.
7. Life expectancy of 3 months or more.
8. Female subjects of childbearing age or male subjects whose partners are female subjects of childbearing age agree to strictly adopt effective contraceptive measures throughout the entire treatment period and 6 months after the treatment period.

Exclusion Criteria:

1. Women who are pregnant or lactating, or intending to become pregnant before, during, or within 6 months after the last dose of study drug.
2. Active or untreated CNS metastases confirmed by imaging evaluation during screening or previous imaging evaluation. Patients with asymptomatic brain metastases may participate in this study.
3. History of active thrombosis or deep vein thrombosis or pulmonary embolism within 4 weeks prior to the first dose of study drug.
4. Clinically significant cardiovascular or cerebrovascular disease.
5. Interstitial pneumonia, pulmonary fibrosis, pneumoconiosis, drug-associated pneumonia, and radiation pneumonitis requiring steroid hormone or other therapy, as well as history of severe abnormal lung function or other forms of restrictive lung disease.
6. History of allergies, asthma, atopic dermatitis.
7. Concomitant pleural or pericardial effusion requiring repeated drainage or with significant symptoms.
8. Active autoimmune disease requiring systemic therapy within 2 years prior to first dose.
9. Known history of allogeneic organ transplantation and allogeneic hematopoietic stem cell transplantation.
10. Subjects with known or suspected hypersensitivity to the study drug and any excipients.
11. Subject has a prior history of significant toxicity associated with immune checkpoint inhibitor administration that requires permanent discontinuation.
12. Subjects with unresolved > Grade 1 toxicity associated with any prior antineoplastic therapy, with the exception of persistent Grade 2 alopecia, peripheral neuropathy, hypomagnesemia, and toxicities that are not expected to be reversible but are stably controlled by medications (e.g., hypothyroidism stably controlled by substitution therapy, hypertension stably controlled by antihypertensive medications with a BP of less than 160/100 mmHg).
13. Inadequate recovery from previous surgery or any major surgery within 4 weeks prior to the first dose of study drug.
14. Active uncontrolled bleeding or known bleeding tendency.
15. Subject has a current or recent (within 6 months) major gastrointestinal disease or condition.
16. Subjects with uncontrolled tumor-related pain or symptomatic hypercalcemia.
17. Known positive HIV test, active hepatitis B, hepatitis C (HCV), tuberculosis.
18. Severe/active/uncontrolled infection, infection requiring systemic intravenous antibiotic therapy, or unexplained fever within 2 weeks prior to the first dose of study drug.
19. Diagnosis of another malignancy within 5 years prior to the first dose, exceptions include radically treated basal cell carcinoma of the skin, squamous cell carcinoma of the skin, and/or radically resected carcinoma in situ, as well as post-radical localized prostate cancer, and papillary thyroid cancer.
20. Exclusion of contraindications to combination medications including, but not limited to: known contraindications to irinotecan therapy for the combination irinotecan or liposomal irinotecan cohort including, but not limited to: having the UGTA1*6/*6, UGT1A1*28/*28, or UGT1A1*6/*28 genotypes; history of prior pelvic and abdominal radiotherapy.
21. Presence of any disease, treatment or laboratory test abnormality, or history or current evidence of substance abuse that, in the judgment of the investigator, may compromise the safety of the subject, interfere with obtaining informed consent, affect subject compliance, or compromise the safety evaluation of the study drug.
22. Mental illness, presence of altered mental status, or substance abuse that prevents understanding of the informed consent process and/or completion of necessary study-related evaluations.
23. For known or foreseeable reasons, the Investigator believes that the subject is unable to fulfill the requirements of the protocol.