2018 年 44 巻 7 号 p. 355-362
Osimertinib is an irreversible epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) that is selective for both EGFR-TKI sensitizing and T790M resistance mutations. Because the application for drug approval was filed in Japan in 2016, few studies analyzing its adverse drug reactions in clinical practice have been reported. In this study, we aimed to evaluate the characteristics of osimertinib by comparing the onset of adverse drug reactions between Kyushu University Hospital (n = 16) and a clinical trial (Japanese subjects in AURA study phase II and AURA2 study: AURA study, n = 80). We found that the rates of decrease in neutrophil and platelet counts were significantly higher in the Kyushu University Hospital study than in the AURA study. At Kyushu University Hospital, a decrease in neutrophil count tended to be reported shortly after the start of treatment, and a decrease in platelet count was expressed over time. It became clear that osimertinib has little effect on hepatic dysfunctions, especially during the early stage of treatment. Consequently, when evaluating adverse drug reactions, it is important to perform a comprehensive analysis that includes aggravation of adverse drug reactions and variations of laboratory data from baseline. We believe that the additional information obtained from our study will lead to improvements in adverse drug reaction monitoring and patient education.
