5PSQ-085 Safety and tolerance profile of osimertinib for treatment of non-small-cell lung cancer

<h3>Background and Importance</h3> Osimertinib is an irreversible tyrosine kinase inhibitor (third-generation TKI) approved in monotherapy for the treatment of metastatic non-small-cell lung cancer (mNSCLC) with activating EGFR mutations and EGFR T790M mutation-positive. <h3>Aim and Objectives</h3> To evaluate the effectiveness and safety of osimertinib in mNSCLC in clinical practice. <h3>Material and Methods</h3> Retrospective observational study, which included all patients treated with osimertinib before June 2024 in a tertiary hospital. Variables collected: age, sex, non-smokers, Eastern Cooperative Oncology Group (ECOG) score, presence of brain metastases, type of mutation, number of lines received and cycles of osimertinib administered. Effectiveness was assessed by progression-free survival (PFS) and overall survival (OS) by the Kaplan-Meier method. Safety was determined by collecting adverse events (AEs) and classifying the degree of toxicity according to the Common Terminology Criteria for AEs v.5.0. Data were collected by electronic medical record and prescription software, analysed in SPSS v.29 statistical software. <h3>Results</h3> Fifty-three patients (75.5% women), median age 64 (48–89) years were analysed. The 62.3% were non-smokers. ECOG was: 0–1 (88.9%) and 2 (9.4%). Brain metastases were present in 64.2%. The most frequent mutation types were: exon 19 deletion (54.7%) and L858R mutation (35.8%). In addition, 13.2% had resistance mutation T790M. The median number of cycles received was 9. At the time of analysis, the median follow-up was 16 months. Of patients, 79.24% received osimertinib as first-line (1L) and 20.75% as second-line (2L). Median PFS was 22 months, 95% CI (10.74–33.25) in 1L and 17 months, 95% CI (3.42–30.57) in 2L. Median OS was 31 months, 95% CI (9.76–52.23) in 1L and 29 months, 95% CI (10.91–47.08) in 2L. AEs were recorded in 57.40% of patients (grade 1: 48.4%, grade 2–3: 9%). The most frequent were diarrhoea (18.5%), rash (16.5%), asthenia (16.5%). Grade 3 AEs were: retinal necrosis, skin lesions, elevated GGT and cardiac failure. <h3>Conclusion and Relevance</h3> The effectiveness results achieved in SLP were superior in both treatment lines compared to their pivotal trials FLAURA (1L) and AURA 3 (2L). However, the OS achieved was lower in 1L and higher in 2L. In terms of safety, there was a lower incidence of AEs and generally mild ones. <h3>References and/or Acknowledgements</h3> <h3>Conflict of Interest</h3> No conflict of interest