OBJECTIVES : To determine the cost per responder (CPR) (achieve 90% and 100% reduction in the PASI [Psoriasis Area Severity Index]) of the biological treatments for moderate to severe psoriasis in Argentina.

METHODS : Using a model developed in Excel, we estimated the number of patients needed to treat (NNT) to achieve a reduction of 90% and 100% in the PASI (PASI-90/100) of the following treatments: Adalimumab, Apremilast, Etanercept, Guselkumab, Infliximab, Ixekizumab, Risankizumab, Secukinumab and Ustekinumab. The incremental CPR was estimated as the costs of drugs associated with treatment over a given time horizon (primary response period [10-16 weeks] or 2 years) multiplied by the NNT. PASI-90/100 response probabilities were extracted from a network meta-analysis of published clinical trials (10-16 weeks). Costs of treatments were estimated based on approved regimens and doses of each drug as well as drug prices obtained from a publicly available list of prices. CPR are presented in Argentine Pesos ($) (exchange rate 1US$ = 70.25$, May 2020)

RESULTS : NNT (PASI 90; 100): Risankizumab (1.42; 2.48), Ixekizumab (1.43; 2.54), Guselkumab (1.51; 2.81), Secukinumab (1.66; 3.36), Infliximab (1.78; 3.79), Ustekinumab (2.34; 6.02), Adalimumab (2.35; 6.10), Etanercept (5.95; 24.39) and Apremilast (9.09; 43.48). CPR for primary response period (PASI 90; 100): Risankizumab ($483,429; $845.701), Guselkumab ($511,643; $949,989), Secukinumab ($631,029; $1,274,764), Ixekizumab ($636,717; $1,126,375), Adalimumab ($698,008, $1,813,118), Ustekinumab ($999,141; $2,576,099), Etanercept ($1,047,402; $4,291,793), Apremilast ($1,078,568; $5,158,369) and Infliximab ($1,228,664; $2,620,220). CPR at 2 years (PASI 90; 100): Risankizumab ($2,064,565; $3,611,709), Guselkumab ($2,066,014; $3,836,054), Ixekizumab ($2,494,476; $4,412,817), Secukinumab ($2641,173; $5,335,524), Adalimumab ($2,832,516; $7,357,634), Apremilast ($2,961,656; $14,164,442), Ustekinumab ($3,552,613; $9,159,750), Etanercept ($4,267,464; $17,486,194) and Infliximab ($4,933,087; $10.520.182).

CONCLUSIONS : Among the therapies evaluated for moderate to severe psoriasis, Risankizumab, Guselkumab and Ixekizumab shown the highest PASI-90/100 response rates; while Risankizumab would have the lowest CPR PASI-90/100 for all time horizons considered.