Secukinumab efficacy in reducing the severity and the psychosocial impact of moderate-to-severe psoriasis as assessed by the Simplified Psoriasis Index: results from the IPSI-PSO study

Background: The utility of the Simplified Psoriasis Index (SPI), a recently developed multidomain tool for assessing psoriasis, was investigated in a study assessing response to secukinumab.

Methods: In an open-label, multicentre study involving 17 French centres, patients with moderate-to-severe plaque psoriasis received secukinumab 300 mg subcutaneously once weekly from baseline to W4, then every 4 weeks until W48. Dermatologist-scored SPI psoriasis severity (proSPI-s) was compared with Psoriasis Area and Severity Index (PASI). Patient self-assessed severity (saSPI-s) and psychosocial impact (SPI-p) were compared with PASI and Dermatology Life Quality Index (DLQI), respectively.

Results: We included 120 patients (69.2% male; mean age 45.9 years; mean duration of psoriasis 21.6 years). Mean baseline scores were as follows: proSPI-s 24.9, saSPI-s 23.5, PASI 23.1, SPI-p 8.2 and DLQI 13.6. Severity scores achieved by 16 weeks (proSPI-s 2.3, saSPI-s 2.2 and PASI 2.2) were maintained to W52. Reductions in mean psychosocial impact scores were maintained to W52 (SPI-p and DLQI, respectively, 2.1 and 1.5 at W16; 1.5 and 1.9 at W52).

Conclusions: Decrease of PASI scores in response to secukinumab was closely correlated with proSPI-s, supporting the latter's suitability for assessing response to therapy. Although the correlation between PASI and saSPI-s was slightly weaker, patients were able to complete a valid assessment of their psoriasis independently, and thus potentially remotely. With the added benefit of psychosocial impact assessment (SPI-p), SPI provides a valid tool enabling patients to assess their own psoriasis, remotely if necessary.