1995P - Long-term benefit of atezolizumab plus chemotherapy in extensive stage small cell lung cancer (ES-SCLC): Exploratory analysis from the IMfirst study

Background

The IMpower133 study demonstrated that treatment with atezolizumab (ATZ) + carboplatin + etoposide improved overall survival (OS) and progression free survival (PFS), and showed long-term benefit ([LTB] defined as OS ≥18 months) in patients with ES-SCLC. To date, no patient characteristics have been identified and validated to predict LTB from chemo-immunotherapy, and limited data exist regarding LTB in a real-world (RW) clinical setting. We previously reported the primary safety and efficacy results of IMfirst (EudraCT: 2019-002784-10), a phase IIIb, single arm study of ATZ + chemotherapy (C) in patients with untreated ES-SCLC in a RW clinical setting in Spain. Here we present the exploratory LTB analysis from IMfirst.

Methods

In this exploratory analysis, we characterized LTB patients (defined as patients who lived ≥24 months). Association of LTB/no-LTB with patient’s and disease characteristics was evaluated with the Chi-square or Fisher’s exact tests. A p <0.05 was considered statistically significant.

Results

A total of 155 patients were enrolled; 25 met the LTB criteria. Median follow-up was 28.4 months (data cut off: 14 Dec 2022). Median OS [95% CI] was 10.0 [8.6, 11.9] months in the overall population and OS at 24 months was 17.7%. Variables with significant association with LTB/non-LTB patients included tumor burden (TB) at baseline (high TB defined as patients with either SLD ≥60 mm, 2 or more metastatic sites, or LDH > ULN), prior radiotherapy (RT) at baseline, and consolidation RT (Table). None of the 17 patients with ECOG PS 2 were classified as LTB. More immune-mediated adverse events were reported in LTB (16%) compared to non-LTB (0.8%) patients. Table: 1995P

Patient characteristics and association with LTB/no-LTB

Conclusions

This exploratory analysis from IMfirst, though limited due to its small sample size, demonstrates LTB from ATZ + C in a broader ES-SCLC patient population, and suggests potential patient characteristics associated with LTB/non-LTB.

Clinical trial identification

EudraCT 2019-002784-10.

Editorial acknowledgement

Medical writing assistance for this abstract was provided by Beatriz Albuixech, PhD, of MSC consulting.

Legal entity responsible for the study

Roche Farma S.A.

Funding

Roche Farma S.A.

Disclosure

M.R. García-Campelo: Financial Interests, Personal, Advisory Board: Roche, Merck, BMS, AstraZeneca, Lilly, Pfizer, PharmaMar, Bayer, AbbVie, GSK, Boehringer; Financial Interests, Personal, Speaker, Consultant, Advisor: Roche, Merck, BMS, AstraZeneca, Lilly, Pfizer, PharmaMar, Bayer, AbbVie, GSK, Boehringer; Non-Financial Interests, Personal, Other, Travel/accommodation expenses: Roche; Financial Interests, Personal, Other, Travel/accommodation expenses: Merck, BMS, AstraZeneca, Lilly, Pfizer, Boehringer. M. Dómine: Financial Interests, Personal, Advisory Board: AstraZeneca, BMS, MSD Oncology, Pfizer, Roche, Takeda. J. de Castro Carpeño: Financial Interests, Personal, Advisory Board: Roche, Merck, BMS, AstraZeneca, Pfizer, PharmaMar, Boehringer Ingelheim, Takeda, Tesaro; Financial Interests, Personal, Speaker, Consultant, Advisor: Roche, Merck, BMS, AstraZeneca, Boehringer Ingelheim, Takeda; Financial Interests, Personal, Other, Travel/accommodation expenses: Roche, Merck, BMS, AstraZeneca. A.L. Moreno Vega: Financial Interests, Personal, Financially compensated role: Roche, AstraZeneca, PharmaMar; Financial Interests, Personal, Other, Travel/accommodation expenses: Roche, Pfizer. S. Ponce Aix: Financial Interests, Personal, Advisory Board: Roche, Merck, BMS, AstraZeneca, Lilly; Financial Interests, Personal, Speaker, Consultant, Advisor: Roche, Merck, BMS, AstraZeneca, Lilly, Pfizer, PharmaMar, Bayer, Amgen, Boehringer Ingelheim, Takeda. E. Arriola: Financial Interests, Personal, Advisory Board: Roche, Boehringer Ingelheim, Lilly; Financial Interests, Personal, Invited Speaker: Takeda, MSD, AstraZeneca, BMS, Thermo Fisher Scientific, Guardant Health, Pfizer; Financial Interests, Personal, Other, Co-founder: Trialing Health; Financial Interests, Institutional, Research Grant: AstraZeneca. E. Carcereny: Financial Interests, Personal, Advisory Board: Roche, Merck, BMS, Pfizer, Boehringer Ingelheim, Takeda; Financial Interests, Personal, Speaker, Consultant, Advisor: Roche, Merck, BMS, AstraZeneca, GSK, Takeda; Financial Interests, Personal, Other, Travel/accommodation expenses: Roche. M. Majem: Financial Interests, Personal, Advisory Board: Amgen, Roche, AstraZeneca, Takeda, Janssen, Cassen Recordati, BMS; Financial Interests, Personal, Invited Speaker: Amgen, Roche, AstraZeneca, Pfizer, Takeda, Helsinn; Financial Interests, Institutional, Funding: BMS, AstraZeneca, Roche. E. Esteban Gonzalez: Financial Interests, Personal, Advisory Board: Roche, Merck, BMS, AstraZeneca, Pfizer, Janssen, Ipsen, Boehringer Ingelheim, Takeda; Financial Interests, Personal, Speaker, Consultant, Advisor: Roche, Merck, BMS, AstraZeneca, Lilly, Pfizer, Bayer, Janssen, Ipsen, Takeda; Financial Interests, Institutional, Funding: Roche, Merck, BMS, AstraZeneca, Lilly, Pfizer, Bayer, Janssen, Ipsen, Takeda. J. Fuentes Pradera: Financial Interests, Personal, Advisory Board: Roche, BMS, Pfizer, GSK. A.L.O. Ortega Granados: Financial Interests, Personal, Advisory Board: Roche, Merck, BMS, Boehringer; Financial Interests, Personal, Speaker, Consultant, Advisor: Roche, Merck, BMS, Boehringer; Financial Interests, Personal, Other, Travel/accommodation expenses: Roche, Merck, BMS. M. Guillot Morales: Financial Interests, Personal, Other, Travel/accommodation expenses: Roche, Merck, Sanofi. B. Massuti Sureda: Financial Interests, Personal, Advisory Board: Roche, Merck, AstraZeneca, Boehringer Ingelheim, Takeda; Financial Interests, Personal, Speaker, Consultant, Advisor: Roche, Merck, BMS, Pfizer, Boehringer. C.A. Fajardo, L. Crama, N. Lerones Laborda: Financial Interests, Institutional, Full or part-time Employment: Roche Farma S.A.. M. Cobo Dols: Financial Interests, Personal, Advisory Board: Roche, BMS, AstraZeneca, Pfizer, Boehringer; Financial Interests, Personal, Other, Travel/accommodation expenses: Roche, BMS, AstraZeneca. All other authors have declared no conflicts of interest.