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Updated Overall Survival and PD-L1 Subgroup Analysis of Patients With Extensive-Stage Small-Cell Lung Cancer Treated With Atezolizumab, Carboplatin, and Etoposide (IMpower133).
- Source :
-
Journal of clinical oncology : official journal of the American Society of Clinical Oncology [J Clin Oncol] 2021 Feb 20; Vol. 39 (6), pp. 619-630. Date of Electronic Publication: 2021 Jan 13. - Publication Year :
- 2021
-
Abstract
- Purpose: IMpower133 (ClinicalTrials.gov identifier: NCT02763579), a randomized, double-blind, phase I/III study, demonstrated that adding atezolizumab (anti-programmed death-ligand 1 [PD-L1]) to carboplatin plus etoposide (CP/ET) for first-line (1L) treatment of extensive-stage small-cell lung cancer (ES-SCLC) resulted in significant improvement in overall survival (OS) and progression-free survival (PFS) versus placebo plus CP/ET. Updated OS, disease progression patterns, safety, and exploratory biomarkers (PD-L1, blood-based tumor mutational burden [bTMB]) are reported.<br />Patients and Methods: Patients with untreated ES-SCLC were randomly assigned 1:1 to receive four 21-day cycles of CP (area under the curve 5 mg per mL/min intravenously [IV], day 1) plus ET (100 mg/m <superscript>2</superscript> IV, days 1-3) with atezolizumab (1,200 mg IV, day 1) or placebo, and then maintenance atezolizumab or placebo until unacceptable toxicity, disease progression, or loss of clinical benefit. Tumor specimens were collected; PD-L1 testing was not required for enrollment. The two primary end points, investigator-assessed PFS and OS, were statistically significant at the interim analysis. Updated OS and PFS and exploratory biomarker analyses were conducted.<br />Results: Patients received atezolizumab plus CP/ET (n = 201) or placebo plus CP/ET (n = 202). At the updated analysis, median follow-up for OS was 22.9 months; 302 deaths had occurred. Median OS was 12.3 and 10.3 months with atezolizumab plus CP/ET and placebo plus CP/ET, respectively (hazard ratio, 0.76; 95% CI, 0.60 to 0.95; descriptive P = .0154). At 18 months, 34.0% and 21.0% of patients were alive in atezolizumab plus CP/ET and placebo plus CP/ET arms, respectively. Patients derived benefit from the addition of atezolizumab, regardless of PD-L1 immunohistochemistry or bTMB status.<br />Conclusion: Adding atezolizumab to CP/ET as 1L treatment for ES-SCLC continued to demonstrate improved OS and a tolerable safety profile at the updated analysis, confirming the regimen as a new standard of care. Exploratory analyses demonstrated treatment benefit independent of biomarker status.
- Subjects :
- Antibodies, Monoclonal, Humanized pharmacology
Antineoplastic Combined Chemotherapy Protocols pharmacology
B7-H1 Antigen pharmacology
Carboplatin pharmacology
Disease Progression
Double-Blind Method
Etoposide pharmacology
Female
Humans
Male
Middle Aged
Neoplasm Staging
Survival Analysis
Antibodies, Monoclonal, Humanized therapeutic use
Antineoplastic Combined Chemotherapy Protocols therapeutic use
B7-H1 Antigen therapeutic use
Carboplatin therapeutic use
Etoposide therapeutic use
Lung Neoplasms drug therapy
Small Cell Lung Carcinoma drug therapy
Subjects
Details
- Language :
- English
- ISSN :
- 1527-7755
- Volume :
- 39
- Issue :
- 6
- Database :
- MEDLINE
- Journal :
- Journal of clinical oncology : official journal of the American Society of Clinical Oncology
- Publication Type :
- Academic Journal
- Accession number :
- 33439693
- Full Text :
- https://doi.org/10.1200/JCO.20.01055