The present work sought to develop a mPBPK model to predict free IL-17A neutralization in skin for secukinumab and ixekizumab and quantitatively relate it with clinical response rates based on 75% reduction in the Psoriasis Area and Severity Index (PASI) score (PASI75) and 90% reduction in PASI score (PASI90). The gene discussed is IL17A; the disease is psoriasis.