A Phase III study of atezolizumab with carboplatin plus etoposide in patients with extensive-stage small cell lung cancer (IMpower133)

Background

The current standard first-line treatment for the majority of patients (pts) with extensive-stage small cell lung cancer (ES-SCLC) is platinum-based chemotherapy with etoposide. Despite initial response rates ranging from 50% to 70%, median survival remains 

Trial design

IMpower133 is a randomized, Phase III, multicenter, double-blinded, placebo-controlled study evaluating the efficacy and safety of atezo + CE vs placebo + CE in treatment-naive pts with ES-SCLC. Pts will be enrolled regardless of PD-L1 expression status. Pts with untreated CNS metastases, autoimmune disease or prior anti-cancer therapy for ES-SCLC will be excluded. Eligible pts will be stratified by sex, ECOG PS and presence of brain metastases, and randomized 1:1 to treatment arms. The induction phase of the study will consist of four 21-day cycles of atezo (1200 mg IV) or placebo with CE (C AUC 5, day 1 + E 100 mg/m², days 1-3) followed by maintenance atezo or placebo until PD per RECIST v1.1. Treatment can be continued until persistent radiographic PD or symptomatic deterioration. Investigator-assessed PFS per RECIST v1.1 and OS are the co-primary endpoints. Secondary endpoints include ORR, DOR, quality of life, safety/tolerability and pharmacokinetics. Approximately 400 pts will be enrolled globally.

Clinical trial identification

NCT: available on poster

Legal entity responsible for the study

F. Hoffmann-La Roche Ltd

Funding

F. Hoffmann-La Roche Ltd

Disclosure

L. Horn: Research: AZ Consulting: Bayer, BI, BMS, Genentech, Lilly, Merck and Xcovery. M. Reck: Consulting/Advisory role and Speaker Bureau for Roche, lIlly, BMS, MSD, AshaZ Zeneca, Pfizer, Boehringer Ingeleim, Celgene. T.S.K. Mok: Leadership/Stocks: Sanomics Ltd Honoraria/Consulting/Research includes: AZ, Roche, Lily, Merck, MSD, BMS, BI, Novartis, Clovis Onc, Amgen, Janssen, AVEO, Biodesix, Prime Oncology, ACEA Biosciences, Vertex, SFJ, GSK, Biomarin, Pfizer. D. Waterkamp: Roche/Genentech employee and stock. S. Lam, A. Sandler: Genentech employee, Roche stock. X. Tang: Roche employee. A. Lopez-Chavez: Genentech employee. G. Giaccone: Consulting or Advisory Role: Clovis, Boehringer- Ingelheim, Celgene Research grants: Karyopharm, Astra-Zeneca; Eli-Lilly. S.V. Liu: Consulting or Advisory Role: Genentech, Boehringer Ingelheim, Ariad, Biodesix, Perthera. All other authors have declared no conflicts of interest.