Erlotinib Fornon-Smallcell Lung Cancer With Leptomeningeal Metastases: A Phaseiistudy (Logik1101)

Lessons LearnedThis phase II trial evaluated the efficacy of erlotinib for patients with non-small cell lung cancer with leptomeningeal metastasis. The 17 cerebrospinal fluid specimens that were available for epidermal growth factor receptor mutation analysis were all negative for the resistance-conferring T790M mutation. The cytological objective clearance rate was 30.0% (95% confidence interval: 11.9%-54.3%). The median time to progression was 2.2 months. The rate of cerebrospinal fluid penetration among these patients was equivalent to those in previous reports regarding leptomeningeal metastasis. Background Leptomeningeal metastases (LM) occur in approximately 5% of patients with non-small cell lung cancer (NSCLC) and are associated with a poor prognosis. However, no prospective study has identified an active chemotherapeutic drug in this setting. Methods Patients were considered eligible to receive erlotinib if they had NSCLC with cytologically confirmed LM. The objective cytological clearance rate, time to LM progression (TTP), overall survival (OS), quality of life outcomes, and pharmacokinetics were analyzed. This study was closed because of slow accrual at 21 of the intended 32 patients (66%). Results Between December 2011 and May 2015, 21 patients (17 with activating epidermal growth factor receptor [EGFR] mutations) were enrolled. The 17 cerebrospinal fluid specimens available were all negative for the T790M mutation, which confers erlotinib resistance. The clearance rate was 30.0% (95% confidence interval [CI]: 11.9%-54.3%), the median TTP was 2.2 months, and the median OS was 3.4 months. Significantly longer TTP and OS times were observed in patients with mutantEGFR(p= .0113 andp< .0054, respectively). The mean cerebrospinal fluid penetration rate was 3.31% +/- 0.77%. There was a good correlation between plasma and cerebrospinal fluid (CSF) concentrations, although there was no clear correlation between pharmacokinetic parameters and clinical outcome. Conclusion Erlotinib was active for LM and may be a treatment option for patients withEGFR-mutated NSCLC and LM.