Health outcomes of pembrolizumab plus chemotherapy in non-small cell lung cancer.

e20527 Background: Pembrolizumab (PEM) is a standard of treatment for advanced or metastatic non-small cell lung cancer (m-nSCLC) in tumors without biomarker actionable. The clinical practice protocol for m-nSCLC in our hospital includes PEM monotherapy if PD-L1 ≥50% and PEM+chemotherapy (PEM+CT) if PD-L1 1-49% or negative. The aim of this study is to determine the effectiveness results of PEM+CT in m-nSCLC in real clinical practice. Methods: It was designed a single center, observational and retrospective study. We included all patients (pts) treated with PEM+CT as first line of therapy with m-nSCLC of September-2019 to August-2023 at a hospital from south Spain, cut-off date 11/30/2023. The primary endpoints were overall survival (OS) and progression-free survival (PFS). The results were analyzed for population and by subgroups (histology, ECOG, previous localized disease (LD) and other), using Kaplan-Meier method. Results: 103 pts were enrolled (89% men), mean age was 66.2 years, 48.5% of pts had ECOG 0, 40.8% ECOG 1 and the rest ECOG 2-3. The tumors were 64.1 % non-squamous histology. 28.2% pts were treated for previous localized disease and 39.8% pts received radiation therapy at some point during treatment. At start of therapy the mean WBC count with PEM+CT was 10.0 x10(9)/L (sd=6.2). With a median follow-up of 10.8 months (m) the median for treatment duration was 5.7 m 95%CI 4.3-7.2.PFS was 7.2 m IC95% 5.9-8.6 for all pts, 6.6 m IC95% 4.6-8.7 for non-squamous and 8.2 m IC95% 4.6-11.7 for squamous histology, p=0.158. OS was 14.2 m IC95% 10.2-18.2 for all pts, 13.1 m IC95% 7.6-18.6 and 14.2 IC95% 9.3-19.2 by non-squamous and squamous histology, respectively, p=0.396.We found statistically significant difference in OS between: pts with ECOG 0-1 (median 15.1 m IC95% 11.6-18.7) vs pts with EOCG 2-3 (median 6.6 m IC95% 1.6-11.6), p=0.046 and pts previously treated pts of LD (median 21.7 m IC95% 2.5-40.8) vs pts with advanced or metastatic disease at onset (median 10.5 m IC95% 5.2-15.9), p=0.025. Another subgroup analysis is shown in table. Conclusions: The effectiveness of PEM+CT was similar in OS and PFS values to that of the pivotal trials. In contrast to these, our results were slightly better in squamous histology. The OS was better in pts with ECOG 0-1 and previously treated of localized disease, highlighting the importance of early diagnosis. Table: see text