Psoriasis: serum ustekinumab levels correlate with clinical response

Takeaway

• Early serum levels of ustekinumab are associated with clinical response in patients with psoriasis.

Why this matters

• This real-world study provides evidence that serum ustekinumab levels can help predict outcomes and direct patient management.

Key results

• 70.9% of patients achieved ≥75% improvement in Psoriasis Area and Severity Index (PASI75) at some point within a year of starting treatment.
• Median serum ustekinumab level was 1.19 μg/mL.
• Early serum ustekinumab levels were associated with 6-month PASI75 in adjusted analysis (OR, 1.38; 95% CI, 1.11-1.71).
  • OR, 3.71; 95% CI, 1.24-11.08 in sensitivity analysis based on very early trough samples 21-28 days after treatment start.
• Serum ustekinumab was not significantly associated with PASI90 or PASI score ≤1.5.
• Anti-ustekinumab antibodies were detected in 3.5% of patients.

Study design

• Study of 491 patients (65.2% men; mean age, 45.7±12.8 years) with ≥1 serum samples (total, 853) obtained 0-56 weeks from start of ustekinumab monotherapy.
• Funding: Medical Research Council, Psoriasis Association, NIHR, National Institute for Health Research Manchester Biomedical Research Centre, and the National Institute for Health Research Newcastle Biomedical Research Centre.

Limitations

• Short duration.