Abstract 662P
Background
Atezolizumab/etoposide/platinum (AEP) and durvalumab/etoposide/platinum (DEP) are widely used standard chemoimmunotherapy regimens for extensive-stage small cell lung cancer (ES-SCLC). Given the lack of a head-to-head comparison of the two regimens, we performed a retrospective observational study to assess the real-world efficacy and safety of AEP and DEP.
Methods
This was a multicenter, retrospective observational cohort study at five hospitals in Japan. A total of 234 patients, who were histologically diagnosed with ES-SCLC by November 2024 and received AEP or DEP regimen, were included in this study. Progression-free survival (PFS) and overall survival (OS) were evaluated using the traditional Kaplan-Meier method and the propensity score weighting method with overlap weights. Multivariate and subgroup analyses were conducted using the Cox proportional hazards regression model.
Results
As of March 1, 2024 (median follow-up time, 10.2 months), the median PFS did not show a significant difference between AEP and DEP (5.32 vs 5.75 months, HR 1.12 [95% CI 0.85–1.48], p = 0.430). The median OS was also comparable for both AEP and DEP (12.88 vs 12.81 months, HR 1.08 [95% CI 0.78–1.49], p = 0.646]. After applying overlap weighting, the median PFS and OS remained similar for both treatment regimens (PFS – AEP 5.32 vs DEP 5.52 months, HR 1.05 [95% CI 0.79–1.39], p = 0.815; OS – AEP 12.29 vs DEP 12.22 months, HR 1.02 [95% CI 0.73–1.41], p = 0.949). A multivariable Cox regression subgroup analysis, considering various characteristics (age, gender, ECOG PS, clinical stage and distal metastasis site) revealed no significant differences in PFS and OS between the two regimens. Additionally, there were no significant differences in treatment-related adverse events of grade 3 or higher and treatment-related deaths between the two regimens (AEP 77.8% vs DEP 70.4% [p = 0.253] and AEP 4.0% vs DEP 5.6% [p = 0.793], respectively).
Conclusions
Our study demonstrated that clinical efficacy and safety profiles were comparable between AEP and DEP.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
IRB of Sendai Kousei Hospital.
Funding
Has not received any funding.
Disclosure
H. Sakashita: Financial Interests, Personal, Invited Speaker: AstraZeneca KK, Ono Pharmaceutical Co. Ltd., Eli Lilly Japan, Thermo Fisher Scientific Inc., Chugai Pharmaceutical Co. Ltd., Taiho Pharmaceutical Co. Ltd., Merck & Co. Inc., Incyte Biosciences Japan G.K., Daiichi Sankyo, Astellas Pharma Inc., JMS Co. Ltd., Nippon Kayaku; Financial Interests, Institutional, Local PI: Chugai Pharmaceutical Co. Ltd., Eli Lilly Japan, AstraZeneca KK; Financial Interests, Institutional, Other, Co-Investigator: GSK plc. T. Aiba: Financial Interests, Personal, Invited Speaker: Chugai pharma. T. Kamoshida: Financial Interests, Personal, Invited Speaker: Boehringer Ingelheim. M. Maemondo: Financial Interests, Personal, Invited Speaker: Ono Pharma, Bristol Myers Squibb, Merck Sharp and Dohme, AstraZeneca, Chugai pharma; Financial Interests, Institutional, Local PI: Ono Pharma, AstraZeneca, Chugai pharma. S. Sugawara: Financial Interests, Personal, Other, Lecture fee: AstraZeneca, Chugai Pharma, Nippon Boehringer Ingelheim, Taiho Pharmaceutical, Pfizer, Lilly, Novartis, Bristol Myers Squibb, Ono Pharmaceutical, MSD K.K, Kyowa Kirin, Takeda, Nippon Kayaku, Merck, Amgen, Thermo Fisher Scientific; Financial Interests, Personal, Other, Lecture Fee: Eisai, Sysmex; Financial Interests, Institutional, Local PI: AstraZeneca, Chugai Pharma, MSD K.K, Daiichi Sankyo, Bristol Myers Squibb, AnHeart, Ono Pharmaceutical, Nippon Boehringer Ingelheim, AbbVie, Parexel International, Amgen, Taiho Pharmaceutical, Accerise, A2 Healthcare, EPS Corporation, Syneos Health, PPD-SNBL. All other authors have declared no conflicts of interest.