Osimertinib is a third-generation, irreversible, oral epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) that potently and selectively inhibits both EGFR sensitizing mutation and EGFRT790M and has demonstrated efficacy in non-small cell lung cancer (NSCLC) central nervous system metastases.
The third-generation EGFR-TKI osimertinib, initially approved as the second-line treatment for patients with T790-mutant NSCLC, demonstrated survival benefits in TKI-naïve EGFR-mutated patients, especially in patients with CNS metastasis.
The EGFR mutational status in the cfDNA from paired CSF and plasma samples from LAC patients with CNS metastases, including 20 brain metastases (BM) and 15 leptomeningeal metastases (LM), was assessed by droplet digital polymerase chain reaction (ddPCR).
Eligible patients were aged 18 years or older (20 years or older in Japan and Taiwan) at the time of study entry, had stage IV NSCLC, with an EGFR exon 19 deletion (ex19del) or exon 21 substitution (Leu858Arg) mutation, an Eastern Cooperative Oncology Group performance status of 0 or 1, and no CNS metastases.
Second-generation TKIs tended to be chosen over first-generation TKIs as frontline therapy in younger patients with uncommon EGFR mutations and without central nervous system metastases.
Patients with advanced NSCLC who received osimertinib after progression of early-generation EGFR-TKIs and CNS metastases on baseline brain scan were retrospectively collected.
Progression of Central Nervous System Metastases in Advanced Nonsmall Cell Lung Cancer Patients Effectively Treated with First-Generation Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitor.
Expert commentary: The recent data supports that EGFR-TKIs and ALK inhibitors are clinically relevant for first-line treatment to prevent and treat CNS metastases in molecularly selected NSCLC patients.
Purpose In patients with epidermal growth factor receptor ( EGFR) mutation-positive advanced non-small-cell lung cancer (NSCLC), there is an unmet need for EGFR-tyrosine kinase inhibitors with improved CNS penetration and activity against CNS metastases, either at initial diagnosis or time of progression.
This review explores the literature reporting the intracranial activity of EGFR TKIs, and finds that there is evidence for varying efficacy of the approved agents, erlotinib, gefitinib, afatinib, and osimertinib in patients with CNS metastases.
Compared with chemotherapy, molecular testing in plasma and tissue followed by osimertinib treatment yielded an additional 0.359 and 0.313 QALYs in the entire U.S. population and the population of those with central nervous system metastases and an EGFRT790M mutation.
The efficacy comparison of two first-generation epidermal growth factor receptor (EGFR) inhibitors erlotinib or gefitinib as first-line treatment for CNS metastasis NSCLC patients with EGFR-sensitizing mutations is yet to be elucidated.
Osimertinib had significantly greater efficacy than platinum therapy plus pemetrexed in patients with T790M-positive advanced non-small-cell lung cancer (including those with CNS metastases) in whom disease had progressed during first-line EGFR-TKI therapy.
Activity and safety of AZD3759 in EGFR-mutant non-small-cell lung cancer with CNS metastases (BLOOM): a phase 1, open-label, dose-escalation and dose-expansion study.
However, epidermal growth factor receptor-tyrosine kinase inhibitors have exhibited high response rates in EGFR mutation-positive lung cancer patients with central nervous system metastases.
Here we report two cases of gefitinib- or erlotinib-pretreated NSCLCs with a T790M mutation-positive (as assessed on plasma through the therascreen EGFR test) disease and untreated, asymptomatic central nervous system metastases that responded to treatment with osimertinib.
We enrolled patients in phase 2 into five cohorts: ALK inhibitor-naive ALK-rearranged NSCLC (cohort 1), crizotinib-treated ALK-rearranged NSCLC (cohort 2), EGFR<sup>T790M</sup>-positive NSCLC and resistance to one previous EGFR tyrosine kinase inhibitor (cohort 3), other cancers with abnormalities in brigatinib targets (cohort 4), and crizotinib-naive or crizotinib-treated ALK-rearranged NSCLC with active, measurable, intracranial CNS metastases (cohort 5).