Cost‐Effectiveness Analysis of Ritlecitinib Compared With No Treatment in Patients With Severe Alopecia Areata in Japan

The efficacy and safety of ritlecitinib, a dual inhibitor of Janus kinase 3 (JAK3) and tyrosine kinase expressed in hepatocellular carcinoma (TEC) family kinases, have been demonstrated in the ALLEGRO phase 2b/3 trial that enrolled patients aged ≥ 12 years with alopecia areata (AA) and ≥ 50% scalp hair loss. The present analysis evaluated the cost-effectiveness of ritlecitinib compared with no treatment for patients with AA and ≥ 50% scalp hair loss in Japan from a societal perspective. A Markov model stratified by health states based on the Severity of Alopecia Tool (SALT) was developed to estimate the lifetime costs, including productivity loss, and quality-adjusted life years (QALYs) associated with the treatment of AA. The comparator was no treatment, and clinical parameters were based on the ALLEGRO phase 2b/3 trial. Costs and QALYs were discounted at an annual rate of 2%, and the incremental cost-effectiveness ratio (ICER) was calculated. Over a lifetime horizon and with the base-case societal perspective, the incremental QALYs and incremental costs of ritlecitinib 50 mg were 1.09 QALYs and 5 262 471 Japanese yen (JPY) (34 766 United States dollars [USD]), respectively. The ICER was 4 816 589 JPY (31 820 USD) per QALY, which was below the cost-effectiveness threshold in Japan of 5 000 000 JPY (33 032 USD) per QALY. A one-way sensitivity analysis showed that parameters with the most notable effect on the ICER were the utility for patients with SALT score ≥ 50, percentage of work time missed due to presenteeism for patients with SALT score ≥ 50, and the discontinuation rate of ritlecitinib 50 mg. These results indicate that ritlecitinib 50 mg is cost-effective compared with no treatment for patients with AA and hair loss on ≥ 50% of the scalp from a societal perspective in Japan.