Study of ZG006 in Participants With Small Cell Lung Cancer or Neuroendocrine Carcinoma

Inclusion Criteria:

• Fully understand the study and voluntarily sign the informed consent form;

• Male or female 18~75 years of age;

• Histologically or cytologically confirmed diagnosis of small cell lung cancer (SCLC), neuroendocrine carcinoma (NEC), who had no standard treatment available, orwere intolerant to standard treatments;

• Archival tissue sample or fresh biopsy tissue sample must be available for DLL3detection;

• Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1;

• Life expectancy ≥ 3 months;

• Must have evaluable or measurable lesion. For lesions that have received radiationtherapy, only after the progression of the lesions, they can be considered evaluableor measurable lesions;

• All adverse events from prior treatment have either returned to baseline or CTCAE 5.0 ≤ Grade 1, except for AEs not constituting a safety risk in the opinions of theinvestigators, e.g. alopecia, hypothyroidism which can be treated with a hormonereplacement, etc.;

• Female and Male patients must agree to use a reliable form of contraception duringthe study treatment period and for at least 6 months after the last dose of thestudy drug.

Exclusion Criteria:

• Patients having received any of the following treatments:

Anti-DLL3 and anti-CD3 drugs (including investigational drugs); Chemotherapy, biotherapy, endocrine therapy (except for hormone replacement), and biological targeted medicines ≤ 4 weeks before the study entry. Local palliative radiotherapy and a small molecule targeted therapy ≤ 2 weeks (or 5 half-lives, whichever is longer) before the study entry; Systemic immunosuppressive medications, such as corticosteroid (doses > 10 mg/day prednisone or equivalent dose) within 14 days prior to the study entry; Use of any vaccines against viral infections (COVID-19, influenza, varicella, etc.) within 4 weeks of study entry;

• Received any blood transfusion, EPO, G-CSF, albumin infusion and renal replacementtherapy within 14 days prior to study entry.

• The main organ function meets any of the following criteria within 7 days prior tostudy entry; Hematological function: ANC < 1.5×10^9/L, PLT < 75×10^9/L, Hemoglobin (Hb) < 100 g/L; Hepatic function: Alanine aminotransferase (ALT) and aspartateaminotransferase (AST) ≥ 3×ULN, ALT and AST ≥ 5×ULN for liver metastases patients;Total bilirubin (TBIL) ≥ 1.5×ULN; albumin < 30g/L; Creatinine clearance (Cockcroft-Gault formula) < 50 mL/min; INR > 1.5 or APTT > 1.5×ULN;

• Medical history, computed tomography (CT) or magnetic resonance imaging (MRI)results indicate the existence of central nervous system (CNS) metastases; Note: Notapplicable to the following conditions: subjects with stable CNS metastases;

• Uncontrollable third cavity effusion (e.g. a large amount of pleural effusion,ascites, or pericardial effusion, etc.) requiring repeated drainage, which wasjudged by the investigator to be unsuitable for study;

• Any other malignancy within 5 years (other than radically removed and has notrecurred tumors including basal cell skin carcinoma, squamous cell skin carcinoma,superficial bladder cancer, localized prostate cancer, cervical cancer and othercancer in situ, etc.);

• Severe cardiac-cerebral vascular disease, including but not limited to:

Acute myocardial infarction, unstable angina, stroke, or received coronary angioplasty or stent implantation within 6 months before study entry; New York Heart Association functional class II to IV congestive heart failure or left ventricular ejection fraction (LVEF) < 50% or the lower limit of normal; Uncontrollable hypertension (even though the best treatment is used but systolic blood pressure ≥ 140 mmHg and/or diastolic blood pressure ≥ 90 mmHg).

QTc (F) interval prolonged in electrocardiography during the screening baseline period (> 480 ms)

• History of autoimmune disease, including but not limited to systemic lupuserythematosus, nephritis, psoriasis, rheumatoid arthritis, inflammatory boweldisease, autoimmune hepatitis (except for the following: type I diabetes mellitus,skin diseases that do not require systemic treatment (such as vitiligo),controllable celiac disease, and childhood asthma that completely resolved inadulthood without intervention);

• Active infection (such as acute bacterial infection, tuberculosis, active hepatitisB/C, active syphilis, or active human immunodeficiency virus infection). Activehepatitis B is defined as: hepatitis B virus DNA titer > 10000 copies/mL or 2000IU/mL; active hepatitis C is defined as: a positive hepatitis C antibody and HCVviral load above the limit of quantification; active human immunodeficiency virusinfection is defined as: antibody positive;

• Active neurologic paraneoplastic syndrome;

• Interstitial lung disease or non-infectious pneumonitis (other thanradiation-induced pneumonia);

• Having received prior allogeneic stem cell transplantation or solid organtransplantation;

• Known allergy to other mAbs or any antibody excipients; the history of a severeallergic reaction, anaphylactoid or other hypersensitivity reactions to humanizedantibodies or fusion proteins;

• Known history of diagnosed neurological or mental disorders, for example, epilepsy,dementia, etc.;

• A female who is pregnant or nursing;

• Patients were deemed unsuitable for participating in the study by the investigatorfor any reason.