A Study of Carboplatin Plus Etoposide With or Without Atezolizumab in Participants With Untreated Extensive-Stage Small Cell Lung Cancer [IMpower133]

A Phase III, Randomized, Double-Blind, Placebo-Controlled Study of Carboplatin plus Etoposide with or without Atezolizumab (Anti-PD-L1 Antibody) in Patients with Untreated Extensive-Stage Small Cell Lung Cancer

Status

Active, not recruiting

Phases

Phase 3

Study type

Interventional

Source

JPRN

Registry ID

JPRN-jRCT2080223248

Enrollment

400

Registered

2016-06-22

Start date

2016-08-31

Completion date

Unknown

Last updated

2026-06-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Small Cell Lung Cancer

Interventions

investigational material(s) Generic name etc : Atezolizumab INN of investigational material : atezolizumab Therapeutic category code : 429 Other antitumor agents Dosage and Administration for Investig

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: -Histologically or cytologically confirmed ES-SCLC -No prior treatment for ES-SCLC -ECOG performance status of 0 or 1 -Measurable disease, as defined by RECIST v1.1 -Adequate hematologic and end organ function

Exclusion criteria

Exclusion criteria: -Active or untreated CNS metastases -Malignancies other than SCLC within the last 5 years -Pregnant or lactating women -History of autoimmune disease -History of idiopathic pulmonary fibrosis, organizing pneumonia, drug induced pneumonitis, idiopathic pneumonitis, or evidence of active pneumonitis on screening chest CT scan. -Positive test for Human Immunodeficiency Virus (HIV) -Active hepatitis B or hepatitis C -Severe infections at the time of enrollment -Significant cardiovascular disease -Prior treatment with cluster of CD137 agonists or immune checkpoint blockade therapies, anti-PD1, and anti-PD-L1 therapeutic antibody

Design outcomes

Primary

Measure	Time frame
efficacy Obserbation, RECIST v1.1	—

Secondary

Measure	Time frame
efficacy pharmacokinetics safety Obserbation, RECIST v1.1	—

Countries

Asia except Japan, Europe, Japan, North America, Oceania, South America

Outcome results

None listed

Source: JPRN (via WHO ICTRP) · Data processed: Jul 3, 2026