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.