Apremilast for genital psoriasis: results from the DISCREET trial

Genital psoriasis can affect up to 63% of patients with psoriasis at some point, but is underdiagnosed and can cause a significant impact on quality of life.¹ Treatment of genital psoriasis is difficult, and topical treatment can lead to side effects such as burning and pruritus due to the thinner and more sensitive skin.¹ Therefore, oral systemic treatments may offer an alternative for patients who experience difficulty with topicals.¹

Here, we summarize results from the phase III DISCREET (NCT03777436) trial by Merola et al.¹ published in Journal of the American Academy of Dermatology. The DISCREET trial compared apremilast, an oral phosphodiesterase 4 inhibitor, with placebo in patients with moderate-to-severe genital psoriasis.¹

Study design and patient population¹

• Patients were enrolled between February 2019 and September 2021, and were randomized 1:1 to either apremilast 30 mg twice daily (n = 143) or placebo (n = 146) for 16 weeks, after which all patients entered an open-label extension and received apremilast up to Week 32.
  
• The primary endpoint was the proportion of patients achieving a modified genital Physician’s Global Assessment (PGA) at Week 16.
• Secondary endpoints included improvement in genital psoriasis Itch Numeric Rating Scale and change in Dermatology Life Quality Index.

The majority of patients were male (69.9%) with a mean age of 45 years. All patients had a genital PGA of moderate (86.9%) to severe (13.1%) at baseline.

Key findings¹

• Over double the proportion of patients in the apremilast group achieved the primary endpoint compared with placebo (Figure 1).

DLQI, Dermatology Life Quality Index; GPI-NRS, Genital Psoriasis Itch Numeric Rating Scale; LS, least squares; PGA, Physician’s Global Assessment.
*Data from Merola, et al.¹

 

• More patients experienced treatment-emergent adverse events in the apremilast group (72%) compared with placebo (57.2%).
• The most common treatment-emergent adverse events were:

• • Diarrhea (8.3% placebo vs 25.9% apremilast)
  • Headache (11.0% placebo vs 23.1% apremilast)
  • Nausea (7.6% placebo vs 22.4% apremilast)
  • Nasopharyngitis (8.3% placebo vs 8.4% apremilast)

Key learnings

Significantly more patients achieved a modified genital PGA when treated with apremilast vs placebo at Week 16. Additional longer-term studies with active comparisons and including sexual function are needed to confirm the most effective treatment options for genital psoriasis. Genital psoriasis is underdiagnosed; therefore, open conversation with patients about all the treatment options may encourage patients to discuss their symptoms with their physician.