an open-label study to evaluate the pharmacokinetics and safety of bimekizumab in pediatric study participants with active juvenile idiopathic arthritis subtypes enthesitis-related arthritis (including juvenile-onset ankylosing spondylitis) and juvenile psoriatic arthritis

Conditions: Enthesitis-related Arthritis; Juvenile Psoriatic Arthritis

Summary: the purpose of this study is to assess plasma bimekizumab concentrations following subcutaneous (sc) bimekizumab administration.


Eligibility criteria:
inclusion criteria: * study participant must be 2 to \<18 years of age inclusive, at the baseline visit. * study participants who have confirmed diagnosis of enthesitis-related arthritis (era; including juvenile-onset ankylosing spondylitis (jas)) and/or juvenile psoriatic arthritis (jpsa) according to the juvenile-international league of associations for rheumatology (jia-ilar) classification criteria of at least 3 months duration prior to the screening visit. * study participants who have active disease (era \[including jas\] and/or jpsa) defined as having at least 3 active joints and for era at least 1 site of enthesitis at baseline or documented by history. * study participants with inadequate response (at least 1 month) or intolerance to at least 1 nonsteroidal anti-inflammatory drug (nsaid). * study participants taking concomitant methotrexate or sulfasalazine are allowed to continue the medication if it has been used for the past 12 weeks with a stable dose for the 4 weeks prior to baseline, with no change in dose for the first 16 weeks of treatment foreseen. (note: prior or concomitant use of methotrexate or sulfasalazine is not required for study participation.) * study participants with no concomitant use of second line agents such as disease-modifying and/or immunosuppressive drugs with the exception of methotrexate or sulfasalazine. * body weight of ≥10kg. * male and female. * a female study participant will be eligible to participate if she is not pregnant, not breastfeeding, and at least 1 of the following conditions applies: 1. not a woman of childbearing potential (wocbp) or 2. a wocbp who agrees to follow the contraceptive guidance during the initial treatment period, the open-label extension (ole) period, and for at least 20 weeks after the final dose of investigational medicinal product (imp; ie, the safety follow-up (sfu) period) * capable of giving/having parent(s) or legal representative provide signed informed consent/assent (where appropriate), which includes compliance with the requirements and restrictions listed in the informed consent form (icf) and assent and in this protocol. exclusion criteria: * study participants fulfilling any international league of associations for rheumatology (ilar) diagnostic juvenile idiopathic arthritis (jia) category other than enthesitis-related arthritis (era; including juvenile-onset ankylosing spondylitis (jas)) and/or juvenile psoriatic arthritis (jpsa). * study participant has history of inflammatory bowel disease (ibd) or signs/symptoms suggestive of ibd. * study participant has active uncontrolled uveitis. * study participant has history of active tuberculosis (tb) unless successfully treated, latent tb unless prophylactically treated. * study participant has had major surgery (including joint surgery) within the 3 months prior to the baseline visit or has planned major surgery within 6 months after entering the study. * study participant has laboratory abnormalities at screening defined in the protocol. * study participant has an active infection or history of infections (such as serious infection, chronic infections, opportunistic infections, unusually severe infections). * study participant has received drugs listed in the protocol outside the specified timeframes relative to the baseline visit or receives prohibited concomitant treatments. * study participant had previous therapy with bimekizumab or prior treatment with other il-17 biologic response modifier. * study participant had prior treatment with more than one biologic response modifier (other than an il-17). * presence of active suicidal ideation, or positive suicide behavior. * study participant has been diagnosed with severe depression in the past 6 months.

Keywords: arthritis bimekizumab