A recent study has revealed that bimekizumab is both safe and effective for elderly patients suffering from moderate to severe plaque psoriasis. The trial, conducted across 33 clinics in Italy between December 2022 and September 2023, showed that more than half of the patients achieved complete skin clearance after 16 weeks of treatment with no serious adverse events reported.
The study included 98 patients aged 65 years or older, with a mean age of 71.1 years. Participants received 320 mg of bimekizumab (two 160 mg injections) every four weeks until week 16, and then every eight weeks thereafter. The primary endpoint was the proportion of patients achieving a 75%, 90%, and 100% reduction in Psoriasis Area and Severity Index (PASI 75, 90, and 100) score compared to baseline at weeks 4, 16, and 36. Secondary endpoints included the proportion of patients achieving a Psoriasis Global Assessment (PGA) score of clear (0) or almost clear (1) at specific sites such as the scalp, palmoplantar region, genitals, and nails.
Significant Improvement in PASI Scores
At baseline, the mean PASI score was 16.6 ± 9.4. After four weeks of bimekizumab treatment, the score significantly decreased to 4.3 ± 5.2, and further decreased to 1.1 ± 1.7 after 16 weeks. This level of improvement was maintained at 36 weeks. Specifically, PASI ≤2 was recorded in 36.7% of patients at week 4, and 69.4% at weeks 16 and 36. By week 16, 87.8% of patients reached PASI75, 72.4% obtained PASI90, and 53.1% achieved PASI100. Binary logistic regression showed no association of baseline PASI, age, gender, or previously naïve state when reaching PASI100 by week 16 or week 36.
Clearance in Difficult-to-Treat Areas
Bimekizumab also demonstrated high efficacy in clearing psoriasis from difficult-to-treat areas:
- Scalp: 77.6% at week 4, 93.9% at week 36
- Palmoplantar: 78.6% at week 4, 88.8% at week 36
- Genital: 89.8% at week 4, 99.0% at week 36
- Nail: 75.5% at week 4, 81.6% at week 36
Safety Profile
The safety profile of bimekizumab was favorable, with only 5.1% of participants reporting adverse events. These included mild eczema (two patients) and oral candidiasis (three patients), none of which required cessation of the therapy.
Study Limitations and Implications
The researchers noted that the study's limitations included a short follow-up period and its observational, retrospective design. However, they emphasized the potential of bimekizumab in achieving biologic-level efficacy with complete skin clearance after 16 weeks of treatment in elderly patients.
"Elders [older patients] are a relevant proportion of patients with plaque psoriasis in clinical practice," the authors wrote. "Therefore, data from observational studies are an important source of evidence to guide for therapeutic choices in this population with special tolerability and efficacy issues."
Bimekizumab was approved in October 2023 as the first FDA-approved IL-17A and IL-17F inhibitor for adults with plaque psoriasis.
