Optimizing treatment strategy in axial spondyloarthritis by molecular imaging with Technetium-labeled certolizumab pegol.

Prior treatment

• Any contraindications to starting therapy with a bDMARD or a tsDMARD
• Patient may not have received any experimental biological and/or non-biological therapy in 3 months preceding study inclusion, or 5 times the half-life of the administered mediation before inclusion in the study.
• Patient may not have received treatment with a bDMARD or tsDMARD in 3 months preceding study inclusion

Other illness

• Documented diagnosis of immune-mediated inflammatory diseases other than axial spondyloarthritis, which may conceal the result of immunoscintigraphy
• Severe renal impairment
• Moderate to severe heart failure (NYHA classes III/IV)
• Latent or active tuberculosis or other severe infections such as sepsis or opportunistic infections
• Known allergy to Certolizumab pegol or any of its excipients

Lab values

• Lack of results of laboratory tests (or results older than 3 months prior to the study inclusion): CRP, ESR, complete blood count, serum creatinine, eGFR, AST, ALT, GGT, HBV, HBC, HIV

Other

• Lack of informed, written consent to participation in the study
• Participation in another clinical study
• Any contraindications to scintigraphy
• Pregnancy or lactation, or refusal to perform a urine stick pregnancy test;

• Patient's informed, written consent to participate
• Male patients whose partners may become pregnant should be surgically sterile or use a condom during intercourse until 35 days after the last scan.
• Age above 18 years old up to 85 years old
• Documented diagnosis of axial spondyloarthritis fulfilling ASAS classification criteria
• Conform with the Belgian reimbursement criteria for starting a bDMARD or tsDMARD for axial spondyloarthritis
• Shared decision of the study participant - the patient - and the treating rheumatologist, to start therapy with a bDMARD or a tsDMARD
• MRI is performed not longer than 3 months prior to the screening visit.
• CRP level >5mg/L (Assessment of CRP levels not longer than 3 months prior to the screening visit)
• Documented insufficient response to treatment with first line medication, i.e. 2 NSAIDs in optimal dose
• Female patients should be either post-menopausal, surgically sterile, or using highly effective contraceptives