This Study Aims to Evaluate the Efficacy and Safety of QLS1317 in Patients With MSI-H/dMMR Advanced Solid Tumors.

Inclusion criteria

-1. Males or females aged ≥ 18 at the time of signing the informed consent form (ICF).

• Expected survival duration ≥ 3 months. 3. Participants with advanced solid tumors of MSI-H/dMMR who have failed standard treatment.

• At least one measurable lesion according to RECIST v1.1. 5. Eastern Cooperative Oncology Group (ECOG) physical performance status score of 0-1.

• Patients with sufficient organ function.

Exclusion criteria

• 1. Have a history of allergy to any component of the study drug. 2. Oral medication is not allowed. 3. The residual toxic reactions caused by previous anti-tumor treatment are higher than Grade 1 according to CTCAE v6.0.

• Known or discovered during screening period to have active central nervous system metastasis.

• Having suffered from other malignant tumors within 5 years prior to the first dose.

• The presence of uncontrollable pleural effusion, pericardial effusion, or ascites that require drainage or treatment.

• Chronic active hepatitis B, active hepatitis C, or human immunodeficiency virus (HIV) infection.

• Suffering from severe cardiovascular and cerebrovascular diseases. 9. Any severe or uncontrollable systemic disease. 10. Have received allogeneic tissue/solid organ transplantation.