Background: Crizotinib, an oral tyrosine kinase inhibitor that targets anaplastic lymphoma kinase, has proven to offer sustained progression-free survival in anaplastic lymphoma kinase-rearranged non-small-cell lung cancers. Occurrence of severe interstitial lung disease (ILD) was one of the crucial adverse events reported in randomized clinical trials and case reports.
Methods: In September 2011, we observed a crizotinib-associated ILD case. Following this index case, we reviewed the clinical and computed tomographic scan features of all patients treated with crizotinib in our department, between October 2010 and July 2013, comparing patients with and without ILD. A systematic literature review was performed.
Results: During this period, 29 patients were treated with crizotinib, five of whom developed ILD, in addition to the index case. Two types of adverse lung reactions may be observed in patients undergoing crizotinib therapy. The first is a severe, usually fatal, ILD that occurs during the first month of treatment (n = 1). The second is a less severe ILD, occurring later in time (n = 5). It occurs gradually with only few clinical symptoms, but predominant ground-glass opacities on computed tomography, along with an intensive lymphocytic alveolitis in bronchoalveolar lavage fluid. These cases had a longer response with a median progression-free survival duration at 19.9 months (17.9-23.5) compared with 6.2 months (1.2-13.6) for controls (p = 0.04).
Conclusion: Forty-nine cases of crizotinib-associated ILD have been identified by the systematic review of the literature, including our six cases. Two types of adverse lung reactions may be observed with different presentation, prognosis, and treatment. Their potential mechanisms should be clarified. Nine patients with the less severe form of ILD were safely retreated.