The epidermal growth factor receptor ( EGFR) is the most common targetable driver in non-small cell lung cancer (NSCLC). Approximately 90% of the EGFR mutations include an exon 19 deletion and a L858R point mutation at exon 21. Less common mutations include, among others, G719X in exon 18, L861Q in exon 21, exon 20 insertions, S768I in exon 20, and T790M in exon 20. Osimertinib is an EGFR TKI that has been developed as non-competitive inhibitor targeting a range of EGFR mutant molecules, currently regarded as the first-line treatment of choice to EGFR mutant (EGFRm) patients. Inhibition of the less common EGFR mutant by osimertinib has been demonstrated.~Real-world data showed lower response rate (RR) and progression free survival (PFS) in patients harboring uncommon EGFR mutations compared to the ones with common mutations treated with EGFR TKIs. Osimertinib as treatment for patients with rare mutations has been assessed in a single arm phase II study in Korea. RR was 50%, PFS was 8.2 months, mOS was not reached. Osimertinib activity in patients with uncommon mutations was assessed also in a retrospective US study, time on treatment ranged from 7.7 months to 19.3 months.~This is a multi-centric, retrospective, real-world study. Study goal is to collect high quality data regarding the efficacy of osimertinib in TKI naive NSCLC patients with uncommon EGFR mutations. The primary endpoints are progression-free survival and overall survival, from osimertinib start. Secondary endpoints would be RECIST response, adverse events, time on treatment and time to CNS progression, CNS response and mechanisms of resistance if tested.~The study includes researchers from Belgium, Denmark, Israel, Switzerland, Netherlands, Germany, France, Italy and USA. Data collection will be conducted at each participating site, following ethics approval. No patient identifying information will leave each of the participating centers. Data will be collected centrally by the lead investigators and analyzed for the entire study cohort and for subgroups if deemed appropriate.
This is a multi-center, retrospective study of ucEGFRmut (exon 20 insertions excluded) metastatic NSCLC osimertinib-treated as first EGFR inhibitor. RECIST and RANO-BM brain objective response rate (ORR) were evaluated by investigators. mPFS, mOS and mDOR were calculated from osimertinib initiation. Mutations found at resistance were collected.