Many patients have localized new bone formation, ligamentous ossification, and progressive deformities that, without treatment, often lead to disability. This disease affects more than 3 million people in China, most of whom are young adults (16-40 years old) 1. The population PK parameters of rhTNFR-Fc in healthy Chinese volunteers and patients with AS were similar to those reported for subjects in published American studies.Īnkylosing spondylitis (AS) is a chronic inflammatory disease that affects the spinal and sacroiliac joints.

Conclusion:Ĭhinese females have a higher CL/F than Chinese males, and multiple dosings can significantly decrease the absorption of rhTNFR-Fc (SC). The inter-individual variability in the CL/F, Vd/F, Ka, and T lag were 33.3%, 42.7%, 55.6%, and 81.8%, respectively.

The outcome parameters were CL/F (female: 0.168 L/h, male: 0.110 L/h), the apparent volume of distribution (Vd/F: 15.5 L), the absorption rate constant (Ka) (single dosage: 0.0605 h −1, multiple dosage: 0.0408 h −1), and the lag time (T lag: 1.03 h). We found that gender had a significant effect on the apparent clearance (CL/F), with the male CL/F ratio being only 0.665 times the female ratio the absorption coefficient (F) of multiple dosages of rhTNFR-Fc was only 0.674 times that of a single dosage. The data were best described by a one-compartment model with lag time. Population pharmacokinetic (PK) analysis was applied to obtain PK parameters of rhTNFR-Fc by the NONMEM method. Twenty male patients with moderate AS were randomly assigned to receive seven consecutive SC injections of rhTNFR-Fc at either 25 mg twice a week (BIW) or 50 mg once a week (QW). Thirty-two healthy volunteers were randomly assigned to receive a single SC injection of 12.5, 25, 37.5, or 50 mg of rhTNFR-Fc. To investigate the population pharmacokinetics of recombinant human tumor necrosis factor receptor-Fc fusion protein (rhTNFR-Fc) administered via subcutaneous (SC) injection in healthy Chinese volunteers and in Chinese patients with ankylosing spondylitis (AS).

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