Psoriasis is a chronic, immune-mediated inflammatory disease that causes the overproduction of skin cells, leading to inflamed, scaly patches on the skin. For individuals with moderate-to-severe forms of the disease, traditional topical treatments are often insufficient, necessitating systemic therapies. Biologics represent a major advancement in this area, targeting specific components of the immune system that drive the inflammatory process. The development of new and more effective biologics is an ongoing process, providing patients and clinicians with additional options to achieve and maintain clear skin. The latest entry into this class is bimekizumab, approved in late 2023 for adult patients.
The Newest Biologic: Bimekizumab (Bimzelx)
In October 2023, the U.S. Food and Drug Administration (FDA) approved bimekizumab-bkzx (Bimzelx) for the treatment of moderate-to-severe plaque psoriasis in adults. This injectable monoclonal antibody targets and neutralizes two pro-inflammatory cytokines, interleukin (IL)-17A and IL-17F.
Mechanism of Action: Dual-Targeting IL-17
Unlike previous biologics targeting only IL-17A, bimekizumab blocks both IL-17A and IL-17F, which are overexpressed in psoriatic lesions. This dual inhibition provides a more comprehensive suppression of the inflammatory process, contributing to its high efficacy rates in clinical trials.
Efficacy and Clinical Trial Results
Based on Phase 3 trials like BE READY and BE SURE, Bimzelx shows rapid and durable skin clearance. Key results include: 91% of patients achieving PASI 90 by week 16 in one study, exceptionally high PASI 100 rates around 70%, significant improvement within two to four weeks, and sustained high clearance rates with maintenance dosing every eight weeks after an initial loading period.
Administration and Side Effects
Bimekizumab is a subcutaneous injection. For adults, initial doses are given at weeks 0, 4, 8, 12, and 16, followed by maintenance every eight weeks. Common side effects include upper respiratory infections, oral candidiasis, headache, and fatigue. Oral candidiasis is more frequent than with other IL-17 antagonists but is usually mild. As with other immunosuppressants, there is an increased risk of infections. Patients should discuss side effects with their doctor.
Comparing Biologics for Psoriasis
Bimekizumab is one of several biologic options. The table below compares Bimzelx with deucravacitinib (Sotyktu), an oral TYK2 inhibitor, and risankizumab (Skyrizi), an IL-23 inhibitor.
| Feature | Bimekizumab (Bimzelx) | Deucravacitinib (Sotyktu) | Risankizumab (Skyrizi) |
|---|---|---|---|
| Mechanism | Dual IL-17A and IL-17F inhibitor | Selective, oral TYK2 inhibitor | IL-23 inhibitor |
| Administration | Subcutaneous injection (initial loading, then every 8 weeks) | Oral tablet (once daily) | Subcutaneous injection (weeks 0, 4, then every 12 weeks) |
| Onset of Action | Rapid, with significant improvements seen within weeks | Rapid, with some improvement seen within a few weeks | Starts working in weeks, but may take longer for full effect |
| Common Side Effects | Oral candidiasis, upper respiratory infections, headache | Upper respiratory infections, acne, mouth ulcers | Upper respiratory infections, injection site reactions, fatigue |
| Patient Suitability | Strong efficacy for those seeking maximum skin clearance | Appeals to patients preferring oral medication or those needle-averse | Convenient dosing schedule (every 12 weeks) is a key feature |
Conclusion
Bimekizumab (Bimzelx) offers a powerful new option for moderate-to-severe plaque psoriasis with high rates of complete skin clearance due to its dual IL-17A and IL-17F inhibition. While oral candidiasis is a notable side effect, it's typically mild. The expanding range of targeted therapies, including biologics like Bimzelx and oral options, allows for personalized treatment and improved quality of life. The National Psoriasis Foundation provides resources on these treatments.
