This s a multi-center, open-label phase Ib/II study to evaluate the safety, tolerability, pharmacokinetics, and efficacy of GH21 combined with D-1553 in patients with advanced or metastatic solid tumors harboring KRAS G12C mutation.

This study includes 2 parts: dose escalation(Phase Ib) and dose expansion (Phase II). The objective of the dose escalation part is to evaluate the safety, tolerability and pharmacokinetics of GH21 in combination with D-1553 in patients with advanced solid tumors harboring KRAS G12C mutation and to determine the RP2D for the combination therapy. In the dose expansion part, preliminary efficacy and safety of the combination therapy at the RP2D will be further explored in patients with specific cancer harboring KRAS G12C mutation.

Inclusion Criteria:

• The patient or his legal representative is able to understand and voluntarily sign a written informed consent (before commencing this study and any research procedure);
• Age ≥18 years old, male or female;
• KRAS G12C mutant advanced solid tumor;
• ECOG Performance Status of 0 or 1
• At least one measurable lesion as defined by RECIST 1.1

Exclusion Criteria:

• acute myocardial infarction, unstable angina pectoris, coronary artery bypass grafting, cerebrovascular accident, or transient ischemic attack within 6 months before first administration; Grade III-IV heart failure based on the New York Heart Association Cardiac Function Scale at screening; During screening, echocardiography (ECHO) showed left ventricular ejection fraction (LVEF) ≤50%;
• Patients who have a history of severe allergy, or have a history of allergy to the experimental drug/any excipient/combination drug, or have a history of allergy to multiple drugs;
• There is an active infection (≥ grade 2) requiring anti-infective treatment or an unexplained fever exceeding 38 ° C within 28 days before the first dose;
• Any toxicity from previous antitumor therapy prior to initial administration has not returned to CTCAE 5.0 rating ≤ Class 1 (unless hair loss, grade 2 peripheral neuropathy, and/or other grade ≤2 adverse events that do not pose a safety risk);
• Pregnant and lactating women;
• The investigator considers that there are any clinical or laboratory abnormalities or other reasons to be unsuitable for participating in this clinical study.