OBJECTIVES: IMbrella A is a Phase III extension study that allowed rollover from Roche/Genentech-sponsored atezolizumab trials, including IMpower133, a Phase I/III trial of first-line atezolizumab or placebo plus carboplatin/etoposide in extensive-stage small cell lung cancer. We report outcomes from an exploratory analysis of IMpower133 with extended time-to-event data for patients who rolled over to IMbrella A. MATERIALS AND METHODS: IMpower133 patients could roll over to IMbrella A to receive atezolizumab 1200 mg intravenously every three weeks if they continued to receive atezolizumab at IMpower133 closure or were in survival follow-up after atezolizumab discontinuation. Overall survival and safety were assessed; only serious adverse events and AEs of special interest were collected in IMbrella A. RESULTS: Eighteen of 26 eligible patients rolled over to IMbrella A. At clinical cutoff (March 16, 2023), median follow-up in the atezolizumab plus carboplatin/etoposide arm (IMpower133 and IMbrella A) was 59.4 months. The three-, four-, and five-year overall survival (95 % CI) estimates were 16 % (11 %-21 %), 13 % (8 %-18 %), and 12 % (7 %-17 %), respectively. In IMbrella A, serious adverse events occurred in three patients (16.7 %), and one adverse event of special interest was reported (grade two hypothyroidism). CONCLUSION: This long-term analysis of patients from IMbrella A previously enrolled in IMpower133 provides the first report of five-year overall survival outcomes in patients with extensive-stage small cell lung cancer treated with first-line cancer immunotherapy and chemotherapy. While limited by small patient numbers and lack of long-term data for the IMpower133 control arm, exploratory overall survival analyses in patients treated with atezolizumab plus carboplatin/etoposide compared favorably with historical data with chemotherapy alone. NCT03148418.

1st Faculty of Medicine Charles University Thomayer Hospital Prague Czech Republic

Clinical Oncology Instituto de Cancer do Estado de São Paulo Hospital Das Clínicas Da FMUSP São Paulo Brazil

Computational Sciences Genentech South San Francisco CA USA

Department of Internal Medicine Seoul National University Bundang Hospital Seongnam South Korea

Department of Lung Cancer and Chest Tumours Maria Skłodowska Curie National Research Institute of Oncology Warsaw Poland

Department of Medical Oncology Chris O'Brien Lifehouse Camperdown NSW Australia

Department of Medical Oncology Clinical Hospital Centre Bezanijska Kosa Belgrade Serbia

Department of Medical Oncology Hospital Universitario Virgen del Rocío Seville Spain

Department of Medical Oncology The Christie NHS Foundation Trust and Division of Cancer Sciences The University of Manchester Manchester UK

Department of Pulmonary Medicine Sendai Kousei Hospital Sendai Japan

Department of Respiratory and Critical Care Medicine Karl Landsteiner Institute of Lung Research and Pulmonary Oncology Vienna North Hospital Klinik Floridsdorf Vienna Austria

Department of Respiratory Care Ludwig Boltzmann Institute for Lung Health Klinik Penzing Vienna Austria

F Hoffmann La Roche Ltd Basel Switzerland

Faculty of Medicine Department of Oncology and Radiotherapy Medical University of Gdańsk Gdańsk Poland

Faculty of Medicine Semmelweis University Budapest Hungary

Genentech South San Francisco CA USA

Illinois Cancer Care Peoria IL USA

Lung Clinic Grosshansdorf Airway Research Center North German Center of Lung Research Grosshansdorf Germany

Medical Oncology Rush University Medical Center Chicago IL USA

Northwest Medical Specialties Puyallup WA USA

Oncology Product Development Safety Genentech Inc South San Francisco CA USA

Product Development Oncology Hematology Genentech South San Francisco CA USA

Roche Product Development China Shanghai China

Thoracic Oncology and Developmental Therapeutics Lombardi Comprehensive Cancer Center Georgetown University Washington DC USA

References provided by Crossref.org

See more in PubMed

ClinicalTrials.gov
NCT03148418