A Cost-per-Responder Analysis of Ritlecitinib vs Baricitinib in Severe Alopecia Areata

Background Ritlecitinib, a JAK3/TEC family kinase inhibitor, and baricitinib, a JAK1/2 inhibitor, are approved for treating severe alopecia areata (AA). Objective Develop a cost-per-responder analysis for ritlecitinib and baricitinib for treating severe AA to estimate the budget impact based on clinical efficacy, available dosages, and pricing structure. Methods A decision tree evaluated cost implications of once-daily ritlecitinib 50 mg, or baricitinib 2 mg and 4 mg treatment over 1 year from a US perspective. Drug costs were estimated using wholesale acquisition costs. Distribution across treatment and dosing options were based on real-world evidence. We defined shorter-term response as Severity of Alopecia Tool (SALT) score relative change from baseline ≥30% (SALT Δ≥30%; SALT 30 ) at Weeks 18 and 24, and longer-term response as absolute SALT score ≤20 at Weeks 36 and 52. Patients initiating baricitinib 2 mg with no shorter-term response could uptitrate to 4 mg or discontinue therapy. Decision probabilities were derived from real-world evidence and clinical trial data. Results At Week 24, 52.10% of ritlecitinib initiators and 36.28% of baricitinib initiators achieved SALT Δ ≥30%; at Week 52, 40.26% and 30.63% of ritlecitinib and baricitinib initiators, respectively, achieved SALT ≤20. Baricitinib had a higher cost per responder than ritlecitinib at Weeks 24 ($54 887 vs $45 577) and 52 ($107 217 vs $94 834). Cost-equivalence was reached at Week 52 ($38 180), with 42.72% of baricitinib patients initiating 2 mg treatment. Sensitivity analyses showed ritlecitinib cost per responder was lower at Week 24 (difference, −$1532) and higher at Week 52 (difference, $10 728) than only baricitinib 2 mg use, and lower at Weeks 24 and 52 (difference, −$20 001 and −$60 073) than only baricitinib 4 mg use. The lower cost per responder for ritlecitinib 50 mg vs baricitinib 2 or 4 mg at Weeks 24 and 52, and greater early efficacy and fewer discontinuations is consistent with the results of a prior indirect treatment comparison that supported favorable outcomes with ritlecitinib 50 mg vs baricitinib 2 mg. Conclusions Ritlecitinib 50 mg demonstrated a lower cost per responder than baricitinib 2 or 4 mg at Weeks 24 and 52, which may inform reimbursement or formulary inclusion of ritlecitinib for treating AA.