Successful crizotinib rechallenge after crizotinib-induced interstitial lung disease.

We report the case of a 70-year-old Japanese male diagnosed with advanced lung adenocarcinoma harboring the echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase fusion gene. As soon as crizotinib was administered, tumor shrank immediately. On Day 25, he developed interstitial lung disease. Bronchoalveolar lavage fluid analysis demonstrated elevated lymphocytes fractionation. A drug lymphocyte stimulating test for crizotinib with the bronchoalveolar lavage lymphocytes was negative. Crizotinib administration was discontinued, but a life-threatening flare of tumor growth occurred. Since there was no alternative treatment for the lung cancer, we restarted crizotinib in combination with prednisolone. The patient experienced neither disease progression nor recurrence of interstitial lung disease at 6 months. In cases in which no alternate treatment is known, crizotinib retreatment combined with steroid therapy after crizotinib-induced interstitial lung disease could be considered after a careful consideration of the potential risks and benefits.