Post-marketing surveillance (PMS) was performed in Japan to obtain information on the safety and efficacy of crizotinib.Target patients included almost all patients with anaplastic lymphoma kinase-positive non-small cell lung cancer who were administered crizotinib. The observation period was 52 weeks. In the present study, we focused on the treatment status and safety of crizotinib therapy and analyzed the real-world data obtained by this PMS (ClinicalTrials.gov: NCT01597258).The safety analysis set included 2028 Japanese patients, and more than half of the patients (56.4%) were nonsmokers. The incidence of adverse drug reactions (ADRs) was 91.6%, and common ADRs (incidence ≥15%) were nausea (32.2%), diarrhea (24.3%), photopsia (18.9%), vomiting (17.5%) and dysgeusia (16.8%). Many patients (623 patients) discontinued treatment of crizotinib because of adverse events within 12 weeks after therapy initiation, which tended to frequently occur in the following cases: (1) elderly, (2) body weight <40 kg, (3) body surface area <1.2 m2 (4) ECOG PS 2-4, (5) higher Brinkman index and (6) history of occupational/environmental exposure such as asbestos/pneumoconiosis. The proportions of patients remaining on crizotinib therapy were 68.2% for 3 months, 55.2% for 6 months and 36.1% for 12 months, with a median duration of 7.9 months. Multivariate analysis with a Cox proportional hazard model identified 10 statistically significant patient background factors influencing the duration of crizotinib therapy.No new safety concerns were observed in this PMS study. Our results provide useful information regarding the status of crizotinib therapy in the clinical setting.
