Hizal, MutluBilgin, BurakPaksoy, NailAçıkgöz, ÖzgürSezer, AhmetCan, Alper2021-08-082021-08-082021Hizal, M., Bilgin, B., Paksoy, N., Açıkgöz, Ö., Sezer, A., Gürbüz, M., Ak, N., Yücel, Ş., Ayhan, M., Erol, C., Demirkıran, A., Mandel, N. M., Shbair, A., Gökmen, İ., Başoğlu, T., Paydaş, S., Demiray, A. G., İriağaç, Y., Şakalar, T., Zeynelgil, E., … Şendur, M. (2021). The real-life efficacy and safety of osimertinib in pretreated advanced non-small cell lung cancer patients with T790M mutation: a Turkish Oncology Group Study. Journal of cancer research and clinical oncology, 10.1007/s00432-021-03748-7. Advance online publication. https://doi.org/10.1007/s00432-021-03748-7https://doi.org/10.1007/s00432-021-03748-7https://hdl.handle.net/20.500.12713/1979Introduction Osimertinib, an irreversible third-generation EGFR-TKI, is the standard of care for second-line treatment of T790M-mutant advanced NSCLC patients whose disease progressed after frst-line EGFR-TKI therapy. In this multicenter study, we aimed to determine the real-life efcacy and safety of Osimertinib in pretreated advanced NSCLC patients with T790M mutation. Materials and methods This retrospective trial included advanced T790M-mutant pretreated NSCLC patients who received Osimertinib from 24 diferent centers in Turkey. Primary endpoint was time-to-treatment discontinuation (TTD). Secondary endpoints were objective response rate (ORR), overall survival (OS), and safety. Results Of 163 patients, 68.7% had EGFR exon 19 deletion and 22.7% had exon 21 L858R mutation. Osimertinib was given as second-line treatment in 96 patients (58.9%) and third-line in 48 patients (29.4%). After median of 13-month follow-up, median TTD was 21.6 months with an 82.2% ORR. Estimated median OS was 32.1 months. Grade 3–4 adverse events were seen in 11.7% of the patients. Conclusion Osimertinib is a highly efective option in second- or third-line treatment of NSCLC patients with T790M mutation, with a favorable safety profle.eninfo:eu-repo/semantics/closedAccessOsimertinibNon-small Cell Lung CancerEGFRT790MSecond LineArticle1834331582WOS:0006797669000012-s2.0-85111543488Q210.1007/s00432-021-03748-7N/A