2024 World Conference on Lung Cancer (WCLC) - Posters-P1.12A.06 A Phase II 80 Mg Osimertinib in Patients with Leptomeningeal Metastases Associated with EGFR Mutation-Positive NSCLC (BLOSSOM)

P1.12A.06 A Phase II 80 Mg Osimertinib in Patients with Leptomeningeal Metastases Associated with EGFR Mutation-Positive NSCLC (BLOSSOM)

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The study summarized here investigates the efficacy and safety of 80mg osimertinib in patients with leptomeningeal metastases (LM) from EGFR mutation-positive non-small cell lung cancer (NSCLC). It highlights a significant clinical challenge due to LM in NSCLC, particularly for patients treated with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs).<br /><br />Existing treatments like intrathecal chemotherapy and whole-brain radiotherapy offer limited efficacy. This Phase II study, conducted across six hospitals in Korea under the BLOSSOM protocol, included patients who had not shown progress post-first or second-generation EGFR TKI treatments. A total of 73 patients were involved, with emphasis on patients negative for the EGFR T790M mutation.<br /><br />Key findings from the study reveal that osimertinib provides promising results even at a standard dose of 80mg. The primary outcome, overall survival (OS), stood at 15.6 months for the full set and 15.0 months for the LM efficacy evaluable set. The objective response rate (ORR) for LM was 51.6%, with a complete response (CR) rate of 15.6% and a progression-free survival (PFS) median of 11.2 months.<br /><br />Remarkably, osimertinib demonstrated effective central nervous system penetration, seen in its CSF to free plasma ratio of 22%. Quality of life assessments showed notable improvements, and the findings indicated that standard doses are effective for disease control in T790M-negative patients, aligning with outcomes from higher dosage studies like the BLOOM study (160mg).<br /><br />This research supports the potential of standard-dose osimertinib to enhance survival and quality of life in NSCLC patients with LM who have limited treatment advancement, especially those without systemic progression.

Asset Subtitle

Jinyong Kim

Meta Tag

Speaker Jinyong Kim

Topic Metastatic NSCLC – Targeted Therapy

Keywords

osimertinib

leptomeningeal metastases

EGFR mutation-positive

non-small cell lung cancer

tyrosine kinase inhibitors

BLOSSOM protocol

T790M mutation

central nervous system penetration

quality of life

progression-free survival