In EGFR-mutant non–small cell lung cancer (NSCLC) and brain metastases, oral osimertinib (Tagrisso) achieved rapid, high, and uniform brain exposure which was followed reduction in total brain metastases volume, according to results from the phase 1 ODIN-BM study (NCT03463525).
A presentation on [11C]osimertinib given during the 2020 World Conference on Lung Cancer Singapore showed that in terms of [11C]osimertinib uptake, uniform brain distribution of osimertinib was recorded in all patients at all 3 time points with PET exams after intravenous (IV) microdose administration (n = 4). MRI also illustrated reductions in total brain metastases volume (range, 55%-95%) after 3 to 4 weeks of treatment with oral [11C]osimertinib (Tagrisso). T1-weighted MRI scans also illustrated tumor reductions after 35 days of treatment with oral osimertinib in 1 patient.
These data support uniform brain distribution of osimertinib in patients with NSCLC and brain metastases,” wrote the study authors in a presentation of the data.
Central nervous system (CNS) metastases occur in 40% to 50% of patients treated with first- or second-generation EGFR TKIs within 3 years of diagnosis and are associated with poor prognosis and quality of life in patients with NSCLC.[11C]osimertinib is a potent and selective third-generation, irreversible, oral EGFR TKI that inhibits EGFR and EGFR T790M. The agent is approved for use as a frontline treatment for patients with metastatic EGFR-mutant NSCLC and as adjuvant treatment following tumor resection in patients with EGFR-mutant NSCLC.