High efficacy of brigatinib for brain metastases in ALK fusion gene-positive non-small cell lung cancer: A case series.

Anaplastic lymphoma kinase (ALK) fusion gene-positive lung cancer often shows brain metastasis at initial diagnosis or during the course of treatment. However, molecular-targeted drugs are known to pass through the blood-brain barrier and present positive effects for central nervous system lesions. There are few reports suggesting how effective molecular-targeted drug therapy alone is for brain metastasis lesions of ALK fusion-positive lung cancer, especially after the first use of ALK-tyrosine kinase inhibitor (TKI) or for bulky brain metastases. A patient in his mid-fifties with stage IV pleural dissemination developed brain metastases after 10 years of crizotinib use, but showed a complete response after switching to brigatinib. Moreover, a patient in her early sixties with stage III recurrent large brain metastases 5 years after chemoradiation therapy experienced dramatic tumor shrinkage with brigatinib. In each case of ALK fusion gene-positive lung cancer with brain metastases, brigatinib showed a high efficacy and was well-tolerated after previous ALK-TKI and for bulky lesions.