Authors' objectives: The academic technology assessment group (ATAG) reviewed a report on gefapixant's additional benefits and cost-effectiveness compared to non-treatment or watchful waiting in patients with refractory or unexplained chronic cough (RCC/UCC) submitted by the manufacturer of gefapixant (MSD K.K.). This report summarizes the results of the review by the ATAG. In evaluating the additional benefits of gefapixant over non-treatment or watchful waiting, the manufacturer submitted data from COUGH-1 and COUGH-2 trials, as the only clinical trials that evaluated gefapixant were the COUGH-1 and COUGH-2 trials. The primary endpoint was the mean change in 24-hour cough frequency at 12 weeks in COUGH-1 and 24 weeks in COUGH-2. The safety and tolerability of gefapixant, including adverse events (AEs) and discontinuations due to AEs, were also evaluated. Gefapixant significantly reduced objective 24-hour cough frequency with an acceptable safety profile in these trials; thereafter, the manufacturer insisted on the additional benefits of gefapixant over the comparator. The randomized COUGH-1 and COUGH-2 trials were also detected in the ATAG's systematic review. The ATAG judged that the manufacturer's method for evaluating the additional benefits of gefapixant based on the COUGH-1 and COUGH-2 trials was appropriate. Thus, as the cost-effectiveness analysis was appropriate, the ATAG examined the manufacturer's analysis. The manufacturer performed a cost-effectiveness analysis for each population using three-state (on-treatment, off-treatment, and death) Markov models. The base-case analysis showed that gefapixant incurred an additional cost of JPY 107,160 and conferred an additional 0.006 quality-adjusted life years (QALYs) compared to the non-treatment or watchful waiting scenario. This resulted in an incremental cost-effectiveness ratio (ICER) of JPY 17,569,051 per QALY gained. The ATAG judged that the overall analysis by the manufacturer was considered appropriate. However, the ATAG identified the following limitations of the manufacturerfs analysis: the health states of the Markov model were not based on cough frequency or severity, and the difference between the mean quality of life scores of the gefapixant groups and placebo groups was not statistically significant in the COUGH-1 and COUGH-2 trials. In conclusion, for patients with RCC/UCC, the results by the ATAG suggested that the ICER for gefapixant compared to non-treatment or watchful waiting is likely to belong to over 10 million per QALY from the perspective of public healthcare payers in Japan.

Project Status: Completed

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

Year Published: 2023

URL for published report: https://c2h.niph.go.jp/en/results/C2H2201.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