Bimekizumab (Bimzelx)

Bimekizumab (Bimzelx) is a biologic medication that blocks two inflammatory proteins called interleukin-17A (IL-17A) and interleukin-17F (IL-17F). These proteins play an important role in causing inflammation in autoimmune diseases. Bimekizumab is approved to treat plaque psoriasis, psoriatic arthritis, ankylosing spondylitis, non-radiographic axial spondyloarthritis, and hidradenitis suppurativa with objective signs of inflammation. By blocking both IL-17A and IL-17F, bimekizumab helps reduce inflammation, improve symptoms, and prevent damage caused by ongoing immune system activity.

How To Take It

Bimekizumab is given as a subcutaneous injection (under the skin). Depending on the condition being treated, some patients may receive an initial loading phase with more frequent doses before transitioning to maintenance treatment. Maintenance dosing is typically either 160 mg every 4 weeks or 320 mg every 4–8 weeks. Your healthcare provider will determine the appropriate dose and schedule based on your diagnosis and treatment response.

Safety Information

Suicidal Ideation and Behavior
Bimekizumab may increase risk of suicidal ideation and behavior. Patients, caregivers, and families should monitor for the emergence or worsening of depression, suicidal ideation, or other mood changes.

Infections
Bimekizumab affects your immune system, increasing the risk of serious infections, including tuberculosis (TB), pneumonia, and other bacterial or fungal infections. Your doctor will screen for TB before starting and monitor for infection symptoms.

Inflammatory Bowel Disease (IBD)
Rarely, bimekizumab may cause new onset or worsening of inflammatory bowel disease (Crohn's disease or ulcerative colitis). Bimekizumab should be avoid in patient with active IBD. Tell your doctor if you develop persistent diarrhea, bloody stool, or unexplained weight loss.

Vaccines
Do not receive live vaccines (such as Yellow Fever vaccine) while taking bimekizumab. Inactivated vaccines are generally safe, but always discuss vaccinations with your healthcare provider before receiving them.

Pregnancy and Breastfeeding
There are currently limited data regarding the use of bimekizumab during pregnancy and breastfeeding. If you are pregnant, planning a pregnancy, or planning to breastfeeding, then please discuss with your doctor.

Summary

Regular follow-up visits are needed to monitor how well bimekizumab is working and to check for side effects. Be sure to tell your doctor about all medications and supplements you take, and do not combine bimekizumab with other biologic medications unless specifically instructed. Bimekizumab can improve symptoms and quality of life for people with specific autoimmune conditions, but it requires careful monitoring by your healthcare team.

Updated June 2026 by Howard Yang, MD, RhMSUS, and reviewed by the American College of Rheumatology Committee on Communications and Marketing.

This information is provided for general educational purposes only. Individuals should consult a qualified healthcare professional for medical advice, diagnosis, and treatment of any medical condition.