Scintigraphic Detection of the Biodistribution of Tumor Necrosis Factor With a Radiolabeled Anti-TNFα in Patients With Active Rheumatoid Arthritis and Active Axial and Peripheral Spondyloarthritis

Patients will be treated with prefilled syringes containing each 200 mg/ml Cimzia® every 2 weeks which will be administered subcutaneously (The first 3 injections, a dosage of 400mg Cimzia® subcutaneously will be administered).

All 20 patients will undergo an immunoscintigraphy with radiolabeled Cimzia®. Certolizumab pegol (Cimzia®) is an engineered humanized monoclonal antibody Fab' fragment with specificity for human TNF-α, manufactured in E. coli. The antibody fragment is subsequently purified and conjugated with high molecular weight polyethylene glycol (PEG) (40kDa). Lyophilized Cimzia® will be conjugated with S-HYNIC (a bifunctional chelator). The conjugate will be radiolabeled with Tc-99m by adding 0.1 mg Tricine, 0.01 mg SnSO4 and 750 MBq Tc-99m pertechnetate. A dose of 750 MBq Tc-99m Cimzia® will be injected intravenously.