575P - Efficacy and safety of dacomitinib in treatment-naïve patients with advanced NSCLC and brain metastasis: A multicenter cohort study

Background

The data for dacomitinib, a second-generation EGFR-TKI, treating patients with advanced non-small cell lung cancer (NSCLC) and brain metastasis was lacking. This study aimed to explore the efficacy and safety of dacomitinib in treating EGFR-mutated advanced NSCLC with brain metastasis in first-line settings.

Methods

Eligible patients were treatment-naïve advanced NSCLC patients with ≥1 brain metastasis no less than 5mm treated with dacomitinib. The primary endpoint was intracranial objective response rate (iORR). Secondary endpoints included intracranial progression-free survival (iPFS), intracranial disease control rate (iDCR), sytemic ORR and DCR, PFS, overall survival (OS), and safety. Response was evaluated per modified Response Evaluation Criteria in Solid Tumors (mRECIST, version 1.1) and Response Assessment in Neuro-oncology, Leptomeningeal Metastasis (RANO-LM) criteria.

Results

Between Jul 2nd, 2019, and Sep 30th, 2022, a total of 87 treatment-naïve patients from four hospitals were included. Data cutoff date was Mar 24th, 2023. Median follow-up time was 17.5 (1.6-34.7)months. For 87 patients with evaluable brain metastasis, iORR was 89.7% and iDCR was 97.7%per mRECIST criteria. Based on RANO-LM criteria, iORR was 71.3% and iDCR was 97.7%. Median iPFS was 26.0 months, and the 1-year and 2-year iPFS rate were 68.9% and 51.5%, respectively. For 75 patients with evaluable extracranial lesions, systemic ORR was 73.8% and DCR was 96.4%. Systemic median PFS was 14.0 months and median OS was 34.0 months (Table). Overall, 86 of 87 (98.9%) patients experienced adverse events (AEs) of any grade. Most AEs were grade 1-2 and no patients died due to severe AEs. The most common (≥20%) AEs included rash (89.7%), oral ulcer (74.2%), diarrhea (67.8%), paronychia (59.8%). Table: 575P

Summary of intracranial and systemic efficacy

Conclusions

Dacomitinib showed promising efficacy and manageable safety profile for advanced NSCLC with brain metastasis harboring EGFR mutation in the first-line treatment.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.