Photo Credit: iStock.com/Mysticfalcon

For patients with genital psoriasis, apremilast improved genital Physician Global Assessment scores, itch, and quality of life with a tolerable safety profile.

Apremilast improved symptom burden and quality of life in patients with genital psoriasis, according to findings published in the Journal of the American Academy of Dermatology.

“Genital psoriasis may be the most stigmatizing form of psoriasis, affecting up to 63% of adults with psoriasis at some time,” Joseph F. Merola, MD, MMSc, and colleagues wrote. “Lack of communication between patients and their health care providers often results in underreporting, underdiagnosis, or misdiagnosis; patients may not feel comfortable raising their concerns, contributing to the underdiagnosis of genital psoriasis. … Studies about the safety and efficacy of treatment for genital psoriasis are limited, and treatment is challenging.”

Dr. Merola and colleagues added that the only medication indicated specifically for patients with the condition is the IL-17 inhibitor ixekizumab. Apremilast, an oral PDE4 inhibitor, is approved generally for psoriasis of all severities.

Study Parameters & Patient Characteristics

The researchers conducted a phase 3, multicenter randomized trial of 289 patients with genital psoriasis. Dr. Merola and colleagues randomly assigned the patients to receive either apremilast (n=143) or placebo (n=146) at 30 mg twice a day for 16 weeks. Investigators stratified the patients as having either a body surface area involvement of less than 10% or 10% or higher. The maximum allowable proportion of patients with less than 10% of body surface area (BSA) involvement was 60% of the total study population. The primary endpoint was the number of patients who attained a modified genital Physician Global Assessment (PGA) response, defined as a score of 0 (clear) or 1 (almost clear), with a decrease of 2 or more points from baseline, at week 16.

Compared with patients in the placebo group, patients treated with apremilast were younger (mean age, 43.5 vs 46.4 years), had a slightly higher BMI (mean, 30.2 vs 29.9 kg/m²), and had genital psoriasis for slightly less time (mean, 11.0 vs 11.9 years). At baseline, most patients in the apremilast (86.0%) and placebo (87.7%) groups had a moderately modified genital PGA score.

Improvements With Apremilast

More than one-third of patients assigned to apremilast achieved the primary outcome, Dr. Merola and colleagues reported, compared with about one-fifth of those assigned to placebo (39.6% vs 19.5%), representing a significant treatment difference of 20.1% (P=0.0003). At 16 weeks, 22.2% of the apremilast group achieved the secondary efficacy outcome of an overall static PGA response compared with 6.9% in the placebo group, for a treatment difference of 15.2% (95% CI, 6.9-23.6; P=0.0004).

The Genital Psoriasis Itch Numeric Rating Scale response was higher among patients assigned to apremilast compared with placebo (47.3% vs 19.6%), for a treatment difference of 27.4% (95% CI, 15.4-39.3; P<0.001), as well as the change in BSA involvement (treatment difference from baseline, -3.33 [95% CI, -5.18 to -1.47]; P<0.001).

Safety Results & In-Practice Use of Apremilast

Dr. Merola and colleagues noted that the safety profile of the apremilast was consistent with events seen in previous trials.

The researchers acknowledged that the study was limited by the lack of an active comparator arm and that only short-term data were available. However, they emphasized the importance of studying genital psoriasis, which is often undiagnosed and untreated despite its significant impact on quality of life in the areas of sexual health, function, and relationships.

“The clinical efficacy of apremilast in patients with moderate-to-severe [genital psoriasis] and the significant improvements in patient-reported QoL demonstrate its potential as a convenient, oral systemic treatment for [genital psoriasis],” Dr. Merola and colleagues wrote.