This is a Phase 1, open-label study evaluating the efficacy and safety of HRXG-K-1939 in combination with Adebrelimab (anti-programmed death-ligand 1 [anti-PD-L1] antibody) in patients with advanced solid tumors. HRXG-K-1939 will be administered to patients in a dose escalation regimen to determine a recommended dose for expansion.

Inclusion Criteria:

1. Voluntarily signed the informed consent form and complied with protocols requirements;
2. Patients with advanced solid tumors that are suitable for immunotherapy;
3. ECOG Performance Status of 0 or 1;
4. Life expectancy ≥ 12 weeks;
5. At least one measurable disease per RECIST v1.1;
6. Tumor specimen availability;
7. Adequate marrow and organ function;
8. Have resolution of toxic effects from prior therapy to Grade 1 or less (except for Grade ≤2 alopecia or neuropathy) per CTCAE v5.0;
9. Patients with fertility are willing to use an adequate method of contraception.

Exclusion Criteria:

1. Previously detected positive driver genes (EGFR, ALK, ROS1, etc.);
2. Have leptomeningeal, or actively progressing CNS metastases (patients with stable brain metastases can be enrolled);
3. Uncontrolled pleural effusion, pericardial effusion, or ascites;
4. Major surgical procedure within 28 days prior to initiation of study treatment or anticipation of need for a major surgical procedure during the course of the study;
5. Prior anti-cancer therapy (e.g., chemotherapy, radiotherapy, hormonal therapy, targeted therapy, immunotherapy, any other investigational or immunomodulatory drugs) within 21 days prior to initiation of study treatment;
6. Live-attenuated vaccination within 28 days prior to initiation of study treatment through 60 days after the end of study;
7. Systemic steroid therapy or other form of immunosuppressive therapy within 14 days prior to initiation of study treatment;
8. Any history of an immune-mediated Grade 4 adverse event or Grade 3 adverse event that resulted in permanent discontinuation;
9. Active or history of autoimmune disease;
10. Active tuberculosis or infection requiring treatment;
11. History of interstitial lung disease;
12. Allergic to research drug ingredients;
13. Prior malignancy within 5 years prior to study entry;
14. Solid organ or allogeneic bone marrow transplant;
15. HIV positive, HCV positive, HBV DNA copies ≥ 10^3;
16. Significant cardiovascular disease;
17. Other situations that are not suitable for inclusion in this study judged by investigator