Nearly 70% of adults with moderate to severe scalp psoriasis achieved complete scalp clearance after 48 weeks of guselkumab treatment, according to a phase 3b randomized clinical trial.

The study, led by Amy McMichael, MD, of Wake Forest University School of Medicine in Winston‑Salem, North Carolina, enrolled 108 adults with skin of color at 45 sites in the US and Canada. Eligible participants had at least 30% scalp surface area involvement, a Psoriasis Scalp Severity Index (PSSI) score of at least 12, and a scalp‑specific Investigator’s Global Assessment (ss‑IGA) score of 3 or greater.

Participants were randomized 3:1 to receive subcutaneous guselkumab 100 mg at weeks 0 and 4, then every 8 weeks, or placebo at weeks 0, 4, and 12 with crossover to guselkumab at week 16.

Primary endpoints were the proportions achieving ss‑IGA 0 or 1 and PSSI 90 at week 16. Secondary endpoints included complete scalp clearance (ss‑IGA 0 and PSSI 100), changes in SSA and PSSI, and patient‑reported outcomes such as the Dermatology Life Quality Index (DLQI), Scalp Itch Numeric Rating Scale (NRS), and Psoriasis Symptoms and Signs Diary.

At week 16:

• 68% of guselkumab‑treated participants achieved ss‑IGA 0 or 1 vs 12% with placebo.
• 66% achieved PSSI 90 vs 4% with placebo.
• Complete scalp clearance was seen in 58% of guselkumab‑treated participants, and 59% achieved PSSI 100.

By week 48:

• 67% achieved ss‑IGA 0 and 68% achieved PSSI 100.
• Mean improvements from baseline in PSSI and SSA were ~95%.

Patient‑reported outcomes improved substantially. At week 16, the mean DLQI change was –9.7 in the guselkumab group vs –2.2 with placebo. A ≥4‑point reduction in scalp itch was reported by 69% of guselkumab‑treated participants vs 24% with placebo.

Adverse events were mainly mild or moderate. Infections occurred in 33% of guselkumab‑treated participants through week 48, with no serious infections or treatment discontinuations.

Researchers concluded that guselkumab demonstrated sustained efficacy and a favorable safety profile in adults with scalp psoriasis and skin of color.

Full disclosures can be found in the published study. 

Source: JAMA Dermatology