2374 - IMpower133: updated overall survival (OS) analysis of first-line (1L) atezolizumab (atezo) + carboplatin + etoposide in extensive-stage SCLC (ES-SCLC)

Background

IMpower133 (NCT02763579), a global phase I/III, double-blind, randomized, placebo-controlled trial, showed that adding atezo (anti–PD-L1) to 1L carboplatin + etoposide for ES-SCLC led to a statistically and clinically significant improvement in OS and progression-free survival (PFS) vs carboplatin + etoposide alone. This combination was US FDA–approved in March 2019. Here we present an exploratory updated OS analysis of IMpower133.

Methods

Patients (pts) without prior systemic tx for ES-SCLC were enrolled. PD-L1 testing was not required for enrolment eligibility, but tissue was collected when possible. Pts were randomised 1:1 to receive four 21-day cycles of carboplatin (AUC 5 mg•mL/min IV, Day 1) + etoposide (100 mg/m² IV, Days 1-3) with either atezo (1200 mg IV, Day 1) or placebo (PBO), then maintenance therapy with atezo or PBO until intolerable toxicity or progression. Pts meeting predefined criteria could receive tx beyond progression. Coprimary endpoints were OS and investigator-assessed PFS. OS interim and final analyses were planned for ≈ 240 and ≈ 306 OS events, respectively. Since OS was statistically significant at the interim analysis, an exploratory updated OS analysis was conducted, and exploratory biomarker analyses are in progress.

Results

201 pts were randomized to the atezo group and 202 to the PBO group. At this updated analysis, 302 OS events had been observed. Median follow-up was 22.9 mo. Median OS remained 12.3 mo in the atezo group and 10.3 mo in the PBO group (HR, 0.76 [95% CI: 0.60, 0.95]; descriptive P = 0.0154). 13% more pts were alive in the atezo group than the PBO group at 12 and 18 mo (Table). Other efficacy analyses, including by PD-L1 status, will be presented.Table: 1736O

Conclusions

The addition of atezo to carboplatin and etoposide continued to provide improvement in OS for 1L ES-SCLC. These results further support this regimen as the new standard of care for untreated ES-SCLC.

Clinical trial identification

NCT02763579.001-Time employment: The Chinese University of Hong Kong; Advisory / Consultancy, Non-remunerated activity/ies: geneDecode Ltd. A. Scherpereel: Advisory / Consultancy, Travel / Accommodation / Expenses: AstraZeneca; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: BMS; Advisory / Consultancy, Travel / Accommodation / Expenses: Roche; Research grant / Funding (institution), Travel / Accommodation / Expenses: MSD. N. Reinmuth: Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: Hoffmann La Roche; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: BMS; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: MSD; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: Boehringer Ingelheim; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: AstraZeneca; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: Novartis; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: Takeda. M.C. Garassino: Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Research grant / Funding (institution): Eli Lilly; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony: Boehringer Ingelheim; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Research grant / Funding (institution): Otsuka Pharma, BMS, Takeda, Celgene; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony: Dephaforum Srl; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Novartis; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Pfizer; Honoraria (self), Advisory / Consultancy: Inivata; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Research grant / Funding (institution): MSD; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Research grant / Funding (institution), Travel / Accommodation / Expenses: AstraZeneca, Roche; Honoraria (self), Speaker Bureau / Expert testimony: ACCMED; Honoraria (self), Speaker Bureau / Expert testimony: Forum Service Srl; Honoraria (self), Speaker Bureau / Expert testimony: Medscape; Honoraria (self), Speaker Bureau / Expert testimony: McCann Healthcare; Honoraria (self), Speaker Bureau / Expert testimony: SOS Srl; Honoraria (self), Speaker Bureau / Expert testimony: Crems Srl; Honoraria (self), Speaker Bureau / Expert testimony, Research grant / Funding (institution): Incyte; Research grant / Funding (institution): Tiziana Sciences, Clovis, Merck, Bayer, GSK; Officer / Board of Directors: Women for Oncology Italy, AIOT; Non-remunerated activity/ies, Scientific Committee/General Member: AIOM, ASCO, AIOT, IASCL, IPOP, TUTOR. J. De Castro Carpeno: Advisory / Consultancy, Travel / Accommodation / Expenses: AstraZeneca; Advisory / Consultancy, Travel / Accommodation / Expenses: Boehringer Ingelheim; Advisory / Consultancy, Travel / Accommodation / Expenses: BMS; Advisory / Consultancy, Travel / Accommodation / Expenses: Merck Sharp and Dohme; Advisory / Consultancy, Travel / Accommodation / Expenses: Novartis; Advisory / Consultancy: Pfizer; Advisory / Consultancy, Travel / Accommodation / Expenses: Roche; Advisory / Consultancy: Takeda; Travel / Accommodation / Expenses: Pierre Favre. R. Califano: Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Research grant / Funding (institution), Travel / Accommodation / Expenses: AZ; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Research grant / Funding (institution), Travel / Accommodation / Expenses: BMS; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: Boehringer Ingelheim; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Research grant / Funding (institution), Travel / Accommodation / Expenses: Lilly Oncology; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Research grant / Funding (institution), Travel / Accommodation / Expenses: MSD; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Research grant / Funding (institution), Travel / Accommodation / Expenses: Novartis; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Research grant / Funding (institution), Travel / Accommodation / Expenses: Pfizer; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Research grant / Funding (institution), Travel / Accommodation / Expenses: Roche ; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Research grant / Funding (institution), Travel / Accommodation / Expenses: Takeda; Research grant / Funding (institution): AbbVie; Leadership role, Non-remunerated activity/ies: ESMO; Research grant / Funding (institution): Clovis; Shareholder / Stockholder / Stock options: The Christie Private Care; Non-remunerated activity/ies: EORTC. M. Nishio: Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Ono Pharmaceutical; Honoraria (self), Advisory / Consultancy: BMS; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Pfizer; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Chugai Pharmaceutical; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Eli Lilly; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Taiho; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): AstraZeneca; Honoraria (self), Advisory / Consultancy: Boehringer Ingelheim; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): MSD; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Novartis; Advisory / Consultancy: Daiichi Sankyo; Advisory / Consultancy: Merck Serono. F. Orlandi: Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses, Non-remunerated activity/ies: F. Hoffmann-La Roche; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Research grant / Funding (institution): AstraZeneca/MedImmune; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: BMS; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: MSD; Honoraria (self), Advisory / Consultancy: Lilly; Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: Pfizer; Research grant / Funding (institution): Amgen, Boehringer Ingelheim, Astellas Medivation, Celltrion, . J.A. Alatorre Alexander: Advisory / Consultancy, Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: Merck-Sharp & Domme; Advisory / Consultancy, Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: AstraZeneca; Advisory / Consultancy, Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: Pfizer; Advisory / Consultancy, Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: Boehringer Ingelheim; Advisory / Consultancy, Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: Eli Lilly; Advisory / Consultancy, Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: Novartis; Advisory / Consultancy, Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: F. Hoffmann La Roche; Advisory / Consultancy, Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: BMS; Leadership role, Travel / Accommodation / Expenses, Full / Part-time employment: Head of Oncology National Institute of Respiratory Diseases Mexico. T.A. Leal: Advisory / Consultancy: Genentech; Advisory / Consultancy: AstraZeneca; Advisory / Consultancy: BMS; Advisory / Consultancy: Bayer; Travel / Accommodation / Expenses, Non-remunerated activity/ies: Mirati Therapeutics. S. Lam: Shareholder / Stockholder / Stock options, Full / Part-time employment: Roche/Genentech. M. McCleland: Full / Part-time employment: Genentech, Inc. Y. Deng: Full / Part-time employment: Genentech, Inc. S. Phan: Full / Part-time employment: Genentech, Inc. L. Horn: Advisory / Consultancy: AstraZeneca; Advisory / Consultancy: AbbVie; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: BMS; Advisory / Consultancy: Genentech/Roche; Advisory / Consultancy: EMD Serono; Advisory / Consultancy: Incyte; Advisory / Consultancy, Research grant / Funding (institution): Xcovery; Advisory / Consultancy: Merck; Research grant / Funding (institution): Boehringer Ingelheim. All other authors have declared no conflicts of interest.

Editorial acknowledgement

Medical writing assistance for this abstract was provided by Kshipra Desai, PhD, CMPP, of Health Interactions, and funded by F. Hoffmann-La Roche.