A study published in Dermatology and Therapy revealed that nail involvement can act as an accessible and readily observable prognostic factor for efficacy in skin psoriasis treatment and guide the selection between two biologics (secukinumab and ustekinumab) having different modes of action.

With the aim of improving outcomes in psoriasis people, Curdin Conrad et al. undertook this study to assess if nail involvement in people having moderate to severe plaque psoriasis can forecast differential skin responses to ustekinumab (anti-interleukin-12/23) and secukinumab (anti-interleukin-17A). Pooling of data was done from the phase 3b CLARITY and CLEAR studies and stratified post hoc by nail involvement status at the baseline.

Evaluation of Psoriasis Area and Severity Index (PASI) 75 and 90 responses over fifty-two weeks and absolute PASI ≤ 3, ≤ 1, and 0 values at weeks sixteen and fifty-two were done. On the basis of medical history, 29.7% (265/891) of people in the ustekinumab arm and 30.4% (269/886) of people in the secukinumab arm presented with nail involvement.

The nail involvement status exhibited little to no impact on secukinumab's effectiveness, as comparable response rates were attained for people with and without nail involvement in terms of PASI 75/90, ≤ 3, and 0 responses; slightly reduced PASI ≤ 1 response were attained in people with nail involvement.

In the ustekinumab group, people with nail involvement attained reduced responses across all the outcomes ascertained. This suggests that nail psoriasis serves as a predictor of inferior skin response to ustekinumab therapy. Thus, in skin psoriasis people with nail involvement, secukinumab must be favored since it was found to offer a disproportionately better clinical outcome when compared to ustekinumab.