Clinical impact of first-line platinum plus two-day etoposide combined with immunotherapy in extensive-stage small cell lung cancer: Retrospective monocentric study—E-twoposide.

e20161 Background: Standard first line treatment for extensive-stage small cell lung cancer typically includes carboplatin, etoposide over 3 days, and immunotherapy. In our center, a modified regimen using a two-day schedule for chemotherapy was implemented with the goal of simplifying treatment delivery while maintaining efficacy. This retrospective study imed to evlauate the clinical outcomes and safety of this approach. Methods: We included all patients with ES-SCLC treated between january 2021 and december 2024 with the following regim : carboplatin (AUC 5) on day 1, etoposide 150mg/m2 on days 1 and 2, combined with immunotherapy (eithe durvalumab or atezolizumab). Primary endpoints were progression free survival and overall survival. Secondary endpoints included treatement related toxicities. Results: A total of 87 patients were included. The median PFS was 4.8 months and the median OS was 11.3months. Grade 3 and 4 adverse events occured in 61% of patients principally haematologic disorders. Unexpected toxicities or treatment-related deaths were not observed. Conclusions: A modified two-day chemotherapy regimen combined with immunotherapy appears to offer comparable efficacy and acceptable safety to the standard approach. This modified regimen allowed the release of 268 chemotherapy treatment slots in our center and, pending prospective evaluation, may represent a feasible alternative to the standard schedule.