ALK inhibitor crizotinib combined with intrathecal methotrexate treatment for non-small cell lung cancer with leptomeningeal carcinomatosis.

Anaplastic lymphoma kinase (ALK) inhibitor has shown dramatic efficacy in non-small cell lung cancer (NSCLC) patients harboring ALK rearrangements in phase I trial. Herein we report two cases of NSCLC patients with leptomeningeal carcinomatosis (LM), treated with ALK inhibitor under emergent use of investigational new drug combined with intrathecal methotrexate treatment. Progression free survival was 10 months and 6 months, respectively, and little additional toxicities were observed. These results suggest that ALK inhibitor might be safely administered even in patients or those with metastases in central nervous system.