Activity of EGFR Tyrosine Kinase Inhibitors in NSCLC With Refractory Leptomeningeal Metastases.

INTRODUCTION

Leptomeningeal metastases (LMs) are associated with dismal prognosis in NSCLC. Optimal management remains unknown in patients with EGFR-mutated NSCLC after initial tyrosine kinase inhibitor (TKI) failure.

METHODS

We conducted a multicenter retrospective study including patients with EGFR-mutated NSCLC and LM. TKI failure was defined as diagnosis of LM on TKI, or progression of known LM on TKI.

RESULTS

Ninety-two patients were included, median age of 60 years, predominantly female (68%), never-smokers (74%). EGFR mutations included L858R (45%), exon 19 deletions (28%), or other mutations (14%). Median time to LM diagnosis was 18.5 months after initial diagnosis of advanced NSCLC. LM was diagnosed after a median of 2 (range: 0-9) systemic therapies. Median overall survival from LM diagnosis was 6.1 months (95% confidence interval [CI]: 4.2-7.6 months). Among 87 patients with TKI failure, patients rechallenged with TKI (n = 50) had a median LM overall survival of 7.6 months (95% CI: 5.7-10.9) compared to 4.2 months (95% CI: 1.6-6.7) in patients without further therapy. Overall, 60% of patients rechallenged with TKI experienced clinical benefit (clinical response or stable disease >2 months), and 23% were treatment failure-free at 6 months. Clinical benefit was reported in 11 of 20 (55%) patients treated with erlotinib after afatinib or gefitinib. Strategies based on increasing dose intensity (n = 17) yielded clinical benefit in 59% of patients. All four patients who received osimertinib after first- and second-generation TKI experienced clinical benefit.

CONCLUSIONS

TKI rechallenge strategies, including dosing intensification, may improve clinical outcomes of patients with LM from EGFR-mutated NSCLC after initial TKI failure.