109P - Efficacy of first-line immune-based combined systemic therapy and brain radiotherapy in patients with brain metastases (BM) from driver gene-negative NSCLC

Background

BM significantly impacts the prognosis of patients (pts) with NSCLC. For pts without targetable gene mutations, treatment options are limited, and the roles of immunotherapy and brain radiotherapy remain controversial. This study aims to examine the effectiveness of first-line immune-based therapies and brain radiotherapy for these pts using real-world data.

Methods

Thirty-nine pts with BM from NSCLC harboring non-sensitizing mutations in EGFR, ALK, or ROS1 were enrolled. The study evaluated the efficacy of first-line immune-based combination therapy and brain radiotherapy. Additionally, it explored the relationship between PD-L1 expression levels in extracranial tissues and intracranial treatment outcomes.

Results

First-line systemic treatment had two groups: one group received immunotherapy plus chemotherapy (I+C, n=21), while the other group received immunotherapy plus antiangiogenic therapy, with or without chemotherapy (I+A±C, n=18). There was no significant difference in intracranial progression-free survival (icPFS), intracranial overall survival (icOS), progression-free survival (PFS), and overall survival (OS) between the two groups (all p > 0.05). Additionally, whether or not to receive brain radiotherapy had no significant effect on survival outcomes (all p > 0.05). There were no significant differences in the intracranial objective response rate (icORR) and intracranial disease control rate (icDCR) between different first-line treatment groups and between those receiving or not receiving brain radiotherapy (all p > 0.05). Analysis of survival results revealed statistically significant differences in icPFS, icOS, PFS, and OS between the PD-L1 high expression group (≥ 50%) and the low expression group (<50%), with p-values of 0.002, 0.003, 0.029, and 0.003, respectively.

Conclusions

Different first-line immunotherapy combinations had no significant effect on the survival outcomes of pts with driver gene-negative BM NSCLC, and brain radiotherapy did not bring additional survival benefits. The PD-L1 TPS expression level in extracranial tissues appears to be a prominent predictor of the efficacy of intracranial immunotherapy.

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.