Apremilast safe, effective in moderate-to-severe genital psoriasis

Treatment with apremilast demonstrates consistent efficacy in genital psoriasis and overall psoriasis symptoms at 16 weeks irrespective of body surface area (BSA) at baseline, suggest the results of the phase III DISCREET trial presented at the recent AAD 2023.

“Genital psoriasis remains highly stigmatized, underdiagnosed, and undertreated,” said the authors, led by Dr Joseph F. Merola from the Brigham and Women's Hospital in Boston, Massachusetts, US.

Merola and his team randomized patients with moderate-to-severe genital psoriasis to receive either apremilast or placebo for 16 weeks, followed by an open-label treatment phase. They also stratified participants by means of the affected BSA: <10 percent or ≥10 percent.

The treatment differences at week 16 for patients with BSA <10 percent (apremilast, n=82; placebo, n=84) were 16.5 percent (95 percent confidence interval [CI], 2.6‒30.4) and 23.4 percent (95 percent CI, 8.2‒38.7) for modified static Physician Global Assessment of Genitalia (sPGA-G) response (score of 0 or 1 with ≥2-point reduction from baseline) and for Genital Psoriasis Itch Numeric Rating Scale (GPI-NRS) response (≥4-point reduction from baseline), respectively. [AAD 2023, abstract 40665]

Additionally, the least-squares (LS) mean difference was ‒14.4 (95 percent CI, ‒21.0 to ‒7.9) for change from baseline in Genital Psoriasis Symptoms Scale (GPSS) total score.

For patients with BSA ≥10 percent (apremilast, n=61; placebo, n=62), the 16-week treatment difference was 23.8 percent (95 percent CI, 7.3‒40.3) for modified sPGA-G response and 29.8 percent (95 percent CI, 11.4‒48.1) for GPI-NRS response. For change from baseline in GPSS total score, the LS mean difference was ‒16.3 (95 percent CI, ‒24.6 to ‒8.1).

Both BSA subgroups saw improvements in the Dermatology Life Quality Index and BSA at week 16.

Apremilast plus topical therapy

These findings were consistent with those from a recent study in Japan, which combined apremilast with topical therapy. The results showed clinically meaningful and sustained efficacy in physician- and patient-reported outcomes at weeks 16 and 32. In addition, tolerability was consistent with prior safety data for apremilast. [Dermatol Ther (Heidelb) 2022;12:1469-1480]

This study included 152 Japanese patients, of whom 136 completed week 32. Of these, 43.7 percent achieved the primary endpoint of sPGA response at week 16, and 40.8 percent maintained response at week 32. [Dermatol Ther (Heidelb) 2022;12:1469-1480]

In addition, at least 40 percent of patients achieved clinically meaningful improvements in skin, scalp, and nails at weeks 16 and 32. They also showed improvements in pruritus, quality of life, and treatment satisfaction at week 16 and maintained at week 32.

Adverse events associated with apremilast treatment included the following: gastrointestinal events, nasopharyngitis, and headache.

“Apremilast is an oral immunomodulating phosphodiesterase 4 inhibitor approved in multiple countries for psoriasis,” said the authors of the current study. “The phase III DISCREET trial evaluated apremilast 30 mg BID for the treatment of genital psoriasis.”