This study will evaluate the efficacy and safety of irinotecan liposome(II) in combination with Ivonescimab as second line treatment for SCLC.

This is a prospective, single-arm, multicenter clinical study assessing the efficacy and safety of irinotecan liposome(II) in combination with Ivonescimab as second line treatment for SCLC who failed first-line platinum-based chemotherapy with or without checkpoint inhibitors therapy.

Inclusion Criteria:

1. Age ≥18 years;
2. Histologically or cytologically confirmed SCLC;
3. Advanced SCLC who failed first-line platinum-based chemotherapy with or without checkpoint inhibitors;
4. The Eastern Cancer Cooperative Group (ECOG) performance score of 0 or 1;
5. Life expectancy of ≥3 months;
6. At least one measurable lesion is present according to the efficacy evaluation criteria for RECIST 1.1（Lesions that have received radiotherapy within 6 months prior to the first dose cannot be used as target lesions）
7. No untreated central nervous system (CNS) metastases or CNS were stable for ≥1 month after treatment
8. Have adequate organ function;
9. All female must have had a negative serum pregnancy test within 72 hours of the first dosing and not be lactating, and study participants and their partners must use effective contraception during the trial and for 6 months after the last dosing of the trial drug.
10. Able and willing to provide a written informed consent;

Exclusion Criteria:

1. Known allergy to irinotecan hydrochloride liposome injection (II) and eboxizumab or drug excipients
2. History of severe active autoimmune disease
3. Participated in other drug studies within 4 weeks before enrollment
4. Imaging during the screening period showed that the tumor surrounded important blood vessels or had significant necrosis and voids, and the investigators determined that entering the study would cause bleeding risk
5. History of major illness within 1 year before the first medication
6. History of esophageal and gastric varices, severe ulcers, unhealed wounds, abdominal fistula, intraperitoneal abscess, or acute gastrointestinal bleeding within 6 months prior to initial administration
7. History of surgery or severe trauma within 4 weeks prior to initial dosing
8. Evidence and history of severe bleeding tendency;
9. Participants who had received or planned to receive a live vaccine within 4 weeks prior to the first study treatment
10. Patients with other cancer in 3 years,exceptions are adequately treated basal cell or squamous cell skin cancer or carcinoma in situ of the cervix
11. History of alcohol abuse, psychotropic substance abuse or drug abuse. Other conditions considered unsuitable for this study by the investigator.