What is bimekizumab?
Bimekizumab (Bimzelx®) is a novel humanised immunoglobulin (IgG1) monoclonal antibody used to treat moderate to severe plaque psoriasis, generalised pustular psoriasis, and psoriatic erythroderma.
Bimekizumab selectively and directly inhibits interleukin 17A and 17F (IL-17A and IL-17F).
It is produced in a genetically engineered Chinese hamster ovary (CHO) cell line by recombinant DNA technology.
What is bimekizumab used for?
Bimekizumab (Bimzelx®) was approved in the European Union and the United Kingdom in August 2021 for treating moderate to severe plaque psoriasis in adults who are candidates for systemic therapy.
It received further marketing authorisation in Japan in January 2022 for the treatment of plaque psoriasis, generalised pustular psoriasis, and psoriatic erythroderma in patients who are not responding adequately to existing treatments.
Bimekizumab was also granted marketing approval in Canada and Australia in early 2022 for treating moderate to severe plaque psoriasis in adults who are candidates for systemic therapy or phototherapy.
Currently, bimekizumab is being evaluated in psoriatic arthritis, ankylosing spondylitis, axial spondyloarthritis, and hidradenitis suppurativa.
How does bimekizumab work?
- Interleukin 17A and 17F (IL-17A and IL-17F) levels are elevated in several immune-mediated inflammatory diseases, driving chronic inflammation and damage.
- Studies have shown significant structural homology (around 50%) between IL-17A and IL-17F. The two isoforms appear to cooperate with other pro-inflammatory cytokines, boosting inflammation.
- Bimekizumab has a high affinity for IL-17A and IL-17F and selectively and potently binds and inhibits the activity of both isoforms.
- This unique dual inhibition mechanism results in normalisation of skin inflammation, consequently improving clinical symptoms.
See also: Interleukin-17 in inflammatory skin disorders.
What are the contraindications and precautions with bimekizumab?
Contraindications
Bimekizumab is contraindicated in patients with:
- Hypersensitivity to the active substance or any of the excipients
- Clinically important active infections (eg, active tuberculosis).
Special precautions
Table 1. Precautions with bimekizumab
| Precautions | |
| Infections |
|
| Pre-treatment screening |
|
| Inflammatory bowel disease |
|
| Hypersensitivity |
|
| Vaccinations |
|
| Pregnancy and lactation |
|
| Contraception |
|
Dosing and administration
- Bimekizumab is available as an injection in pre-filled syringes or pre-filled pen injectors.
- Bimekizumab is administered by subcutaneous injection into the thigh, abdomen, or upper arm.
- The recommended dose for adult patients with plaque psoriasis is 320 mg (two 160mg injections) at week 0, 4, 8, 12, and 16, and every 8 weeks thereafter.
- No dose adjustment is needed in the elderly or patients with renal or hepatic impairment.
- Injection sites should be rotated, and injections should not be given into areas where the skin is tender, bruised, or affected by psoriasis.
- The pre-filled syringe or pen should not be shaken.
- Patients can self-administer bimekizumab once they have been trained in subcutaneous injection technique.
- For patients with a body weight ≥ 120 kg who do not achieve complete skin response, a dose of 320 mg every 4 weeks after Week 16 may be considered.
What are the benefits of bimekizumab?
- Bimekizumab rapidly improves the skin condition, reducing itching, pain, and scaling of the skin in patients with moderate to severe plaque psoriasis.
- During clinical trials, most patients achieved a reduction of about 90% in Psoriasis Area and Severity Index (PASI) scores after 16 weeks.
- The positive effects of bimekizumab were maintained with continued use for up to one year.
- It is well tolerated and has a good safety profile.
- It offers an additional treatment option to patients resistant to other biologic treatments.
What are the disadvantages of bimekizumab?
- No formulation containing 320mg bimekizumab is currently available; administering two 160 mg injections is less convenient for patients.
- The elderly are more likely to experience certain adverse reactions such as oral candidiasis, dermatitis, and eczema.
- Infections are the most significant safety concern associated with bimekizumab, requiring consistent monitoring for signs and symptoms of infection.
- Further studies are required to determine if the positive effects of bimekizumab are sustainable beyond one year.
What are the side effects and risks of bimekizumab?
The most frequently reported side effect (>10%) of bimekizumab treatment is upper respiratory tract infections (eg, nasopharyngitis).
Common side effects (1-10%) include:
- Oral candidiasis
- Tinea infections
- Ear infections
- Herpes simplex infections
- Folliculitis
- Dermatitis and eczema
- Acne
- Injection site reactions (eg, injection site erythema, reaction, oedema, pain, or swelling)
- Gastroenteritis
- Headache
- Fatigue.
If you are not based in New Zealand, we suggest you refer to your national drug approval agency for further information about medicines (eg, the Australian Therapeutic Goods Administration and the US Food and Drug Administration) or a national or state-approved formulary (eg, the New Zealand Formulary and New Zealand Formulary for Children and the British National Formulary and British National Formulary for Children).