Cost of Illness of Japanese Patients with Chronic Lymphocytic Leukemia (CLL), and Budget Impact of the Market Introduction of Ibrutinib

Background Ibrutinib was introduced in Japan in 2016 as a new oral treatment option for patients with relapsed/refractory (RR) chronic lymphocytic leukemia (CLL). There is increasing interest from the Japanese government to assess economic aspects of new medical interventions, especially in the area of oncology. Objective We describe the treatment patterns of Japanese patients with CLL, estimate the cost of the disease from a health insurance perspective, and predict the budget impact of the introduction of ibrutinib. Methods A budget impact model was set up and populated with data that were collected from a survey of Japanese hematologists (n = 202) and official statistics. Uncertainty was addressed by one-way sensitivity analysis of several model parameters. Results Among the 2000 Japanese CLL patients, 42.2% have not yet commenced medical treatment, 29.1% were on a treatment break, and 26.8% received medical treatment, mainly rituximab in combination with either fludarabine or bendamustine. Among the patients under medical treatment, 65.7% were receiving first-line treatment and 34.3% were receiving second-line or later treatment. In Japan, the estimated burden of illness for 2015 was ¥1563 million for RR CLL and ¥5471 million for overall CLL. The expected average budget impact of introducing ibrutinib is ¥3077 million per year for the next 5 years. Conclusion Due to low disease prevalence, the burden of illness in Japan is low compared with Western countries.