Title
A Randomized, Open-label Study of HLX10 plus Chemotherapy (Carboplatin-Etoposide) in comparison with Atezolizumab plus Chemotherapy in Previously Untreated US Patients with Extensive Stage Small Cell Lung Cancer (ES-SCLC)

Description
This is a randomized, open-label study of Serplulimab plus chemotherapy (Carboplatin-Etoposide) in comparison with Atezolizumab plus chemotherapy in previously untreated US patients with ES-SCLC.

Subjects in this study will be randomized to arm A or B at 1:1 ratio as follows:

Arm A (Serplulimab): Serplulimab + chemotherapy (carboplatin-etoposide)

Arm B (control): Atezolizumab + chemotherapy (carboplatin-etoposide)

Objective
Primary objective: To compare the efficacy of HLX10 plus chemotherapy versus atezolizumab plus chemotherapy in US patients with previously untreated ES-SCLC.

Secondary objective:
To evaluate the efficacy of HLX10 plus chemotherapy in US patients with previously untreated ES-SCLC.
To evaluate the clinical safety, the pharmacokinetics and immunogenicity of HLX10 in combination with chemotherapy in US patients with previously untreated ES-SCLC.

Treatment Drug: Serplulimab + chemotherapy (carboplatin-etoposide)
Drug: Atezolizumab + chemotherapy (carboplatin-etoposide)

Key Eligibility Inclusion Criteria:

Histologically or cytologically diagnosed with ES-SCLC (according to the Veterans Administration Lung Study Group staging system).
No prior systemic therapy for ES-SCLC.
Major organs are functioning well.
Participant must keep contraception.

Exclusion Criteria:

Histologically or cytologically confirmed mixed SCLC.
Known history of severe allergy to any monoclonal antibody.
Known hypersensitivity to carboplatin or etoposide.
Pregnant or breastfeeding females.
Patients with a known history of psychotropic drug abuse or drug addiction.
Patients who have other factors that could lead to the early termination of this study based on the investigator's judgment.

Applicable Disease Sites
Lung

Participating Institutions
UW Health Eastpark Medical Center; UW Health University Hospital