Authors' objectives: The academic technology assessment group (ATAG) reviewed a report on bimekizumab's additional benefits and cost-effectiveness compared with ixekizumab in patients with plaque psoriasis who are not sufficiently responding to existing treatments submitted by the manufacturer of bimekizumab (UCB Japan Co. Ltd.). This report provides a summary of the results obtained from the review and the reanalysis conducted by the ATAG. In the phase of assessing additional benefits, the manufacturer identified 102 randomized controlled trials (RCT) by conducting a systematic review and performed a network meta-analysis (NMA). The manufacturer asserted that bimekizumab has additional benefits over ixekizumab due to its higher percentage of achieving psoriasis area and severity index 75, 90, and 100 thresholds. The ATAG reconducted the NMA by adding several RCTs. They were concerned about uncertainty regarding the NMA methodology; however, they concluded that bimekizumab has additional benefits compared to the comparator. The manufacturer conducted a lifetime cost-effectiveness analysis comparing bimekizumab with ixekizumab using a Markov model. The model assumed that all patients would initiate treatment with either bimekizumab or ixekizumab. In the event of discontinuation of the primary treatment, all patients were assumed to transition seamlessly to a secondary treatment with risankizumab, which would be continued for the rest of their lives. The results of the base-case analysis reported that incremental costs were -453,808 Japanese Yen (JPY), incremental effects were 0.198 quality-adjusted life years (QALYs), and the incremental cost-effectiveness ratio (ICER) was dominant. The ATAG conducted a reanalysis due to the identification of several challenges in the analysis. First, the manufacturer assumed that a certain number of patients receiving treatment with maintaining the initial treatment interval would occur during the maintenance period of each treatment. The ATAG decided that the estimation method for the ratio of maintaining initial treatment interval had some challenges related to validity. Therefore, the mean medical costs per 2-week maintenance period were estimated using a claims database. Additionally, the secondary treatment setting was an obvious cause of increased uncertainty in the model. The ATAG noted that the secondary treatment assumptions, including the initiation of secondary treatment by all discontinuation of the primary treatment patients and a discontinuation rate of 0% regardless of secondary treatment outcome, may differ from real clinical settings. Therefore, the ATAG decided to conduct the base-case analysis considering parameters up to the primary treatment, and also performed a scenario analysis varying the secondary treatment initiation rate and time horizons. In the base-case results, for bimekizumab compared with ixekizumab, the incremental costs were 360,189 JPY, and incremental QALYs were 0.183, resulting in an ICER of 1,965,600 JPY per QALY. Slight changes in the key parameters had varied the results of the analysis from dominant to positive ICER. The ATAG considered the estimating cost of bimekizumab and the comparator to be approximately comparable. Hence, there is a question regarding the appropriateness of calculating a point estimate for ICER. Finally, the ATAG concluded that it is most probable that ICER was included in the less-than-2-million JPY per QALY range.

Project Status: Completed

URL for project: https://c2h.niph.go.jp/en/

Year Published: 2023

URL for published report: https://c2h.niph.go.jp/en/results/C2H2203.html

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: Japan

Organisation Name: Center for Outcomes Research and Economic Evaluation for Health

Contact Address: 2-3-6 Minami, Wako-shi, Saitama 351-0197 Japan

Contact Name: Takeru Shiroiwa

Contact Email: t.shiroiwa@gmail.com