A Phase II/III Study of IBB0979 in Combination With Topotecan Versus Topotecan in Relapsed Small Cell Lung Cancer

Inclusion criteria

• Aged ≥18 and ≤75 years, male or female.
• Histologically confirmed SCLC.
• Relapsed small cell lung cancer (limited-stage, extensive-stage) that has failed or progressed after first-line or second-line systemic therapy.
• At least one measurable lesion according to RECIST version 1.1.
• ECOG PS 0 or 1.
• Life expectancy ≥ 3 months.
• Adequate organ function.
• Men or women should be using adequate contraceptive measures throughout the study. Females subjects must not be pregnant at screening or have evidence of non-childbearing potential.
• Signed and dated Informed Consent Form.

Exclusion criteria

• Combined SCLC, any previous diagnosis of transformed SCLC or SCLC that has transformed to NSCLC.
• Known hypersensitivity (≥ Grade 3) to recombinant proteins or any excipient contained in the drug or vehicle formulation for IBB0979.
• History of anti-tumor therapy (chemotherapy, radiotherapy, biological therapy, endocrine therapy, targeted therapy within 4 weeks) prior to the initiation of investigational product administration.
• History of any un-marketed investigational product or therapy within 4 weeks prior to the initiation of investigational product administration.
• History of major organ surgery (with exception of aspiration biopsy) or significant trauma within 4 weeks prior to the initiation of investigational product administration, or selective operation is required during the trial.
• History of systemic corticosteroid therapy with exceptions defined in the protocol.
• Treatment with immunomodulatory agents, including but not limited to thymosin, interleukin-2 and interferon within 14 days prior to the initiation of investigational product administration.
• Vaccination with any live virus vaccine within 4 weeks prior to the initiation of investigational product administration.
• History of prior allogeneic stem-cell or solid organ transplantation.
• Unresolved toxicity from prior anti-tumor therapy, defined as not having resolved to Common Terminology Criteria for Adverse Events (CTCAE) version 5.0 grade 1 with exceptions defined in the protocol.
• Untreated brain metastases with exceptions defined in the protocol.
• Evidence of active infection requiring intravenous anti-infective therapy.
• Have a history of immune deficiency, including a positive test for human immunodeficiency virus (HIV) antibodies.
• Active hepatitis B, active hepatitis C.
• Currently has interstitial lung disease (with exception of radiation pulmonary fibrosis that requires no hormone therapy).
• History of severe cardiovascular and cerebrovascular diseases.
• Active or suspected autoimmune diseases (such as systemic lupus erythematosus, rheumatoid arthritis, vasculitis, etc.) with exceptions defined in the protocol.
• History of ≥ grade 3 immune-related adverse events (irAE) or Grade 2 immune-associated myocarditis accompanied with immunotherapy with exceptions defined in the protocol.
• History of other malignancy with exceptions defined in the protocol.
• Pleural effusion/peritoneal effusion/Pericardial effusion requiring clinical intervention.
• Known alcohol or drug dependence.
• History of mental disorder or poor adherence.
• The female patient who is pregnant or breastfeeding.
• History of other severe systemic disease, or any issue that in the opinion of the investigator, would contraindicate the patient's participation in the study.