This is a Phase I clinical study of HS-20093. The purpose of this study is to evaluate the safety, tolerability, PK and efficacy of HS-20093 in combination with Adebrelimab in patients with Extensive Stage Small Cell Lung Cancer (ES-SCLC).

This is a multicenter, open-label Phase I clinical study to evaluate the safety, tolerability, PK and efficacy of HS-20093 in combination with Adebrelimab in patients with ES-SCLC. Patients with ES-SCLC without disease progression after receiving first-line standard induction therapy (Platinum + Etoposide +PD- (L) 1 inhibitor combination therapy) will receive maintenance therapy of HS-20093 in combination with Adebrelimab. Patients will continue treatment until disease progression or other criteria for termination of treatment are met.

Inclusion Criteria:

Subjects must meet all of the following inclusion criteria to be eligible for participation in this study:

1. Men or women aged more than or equal to (≥) 18 years.
2. Pathologically diagnosed as ES-SCLC.
3. Without disease progression after receiving first-line standard induction therapy (Platinum + Etoposide +PD- (L) 1 inhibitor combination therapy).
4. Eastern Cooperative Oncology Group (ECOG) performance status: 0~1.
5. Estimated life expectancy >12 weeks.
6. Adequate bone marrow reserve or serious organ dysfunction
7. Reproductive-age women agree to use adequate contraception and cannot breastfeed while participating in this study and for a period of 6 months after the last dose. Likewise, men also consent to use adequate contraceptive method within the same time limit.
8. Females must have evidence of non-childbearing potential.
9. Signed and dated Informed Consent Form.

Exclusion Criteria:

1. Uncontrolled pleural effusion or ascites or pericardial effusion.
2. Known and untreated, or active central nervous system metastases.
3. Active autoimmune diseases or active infectious disease
4. Known to have interstitial pneumonia or immune pneumonia
5. History of severe allergic reaction, serious transfusion reactions or Allergy to any component of HS-20093
6. The subject who is unlikely to comply with study procedures, restrictions, or requirements judged by the investigator.
7. The subject whose safety cannot be ensured or study assessments would be interfered judged by the investigator.
8. Pregnant women, breastfeeding women or woman who has a child-bearing plan during the study.
9. History of neuropathy or mental disorders, including epilepsy and dementia.