Abatacept reduces paw edema, and the SC Multiple-dose group shows significantly greater (t obs = 2.50) paw edema reduction compared with the IV dose group. Abatacept exhibits linear PK across the studied doses. The NCA clearance (CL) is 20.8 mL/day/kg, volume (V ss ) is 146 mL/kg, and bioavailability (F) of the SC dose dosing is 57.7%. Abatacept (oral; 10 mg/kg; every 2 days) reduces the proportion of activated T cells (CD44highCD62L–) and inhibits the up-regulation of ICOS and CD71 in homozygous DO11.10 RAG-2 –/– BALB/c (H-2d/d) mice. Animal Model: Male Lewis rats (6-9 weeks old) with weights of 150-175 g Dosage: 10 mg/kg (IV), 20 mg/kg (SC single-dose), 20 mg/kg (SC Multiple-dose) on day 21 with 10 mg/kg SC doses on days 23, 25, 27, and 29 Administration: IV or SC Result: Reduced paw edema, and the SC Multiple-dose group showed significantly greater (t obs = 2.50) paw edema reduction compared with the IV dose group. Animal Model: Male Lewis rats (6-9 weeks old) with weights of 150-175 g Dosage: 10 mg/kg (IV), 20 mg/kg (SC single-dose), 20 mg/kg (SC Multiple-dose) on day 21 with 10 mg/kg SC doses on days 23, 25, 27, and 29 (Pharmacokinetic Study) Administration: IV or SC Result: The NCA clearance (CL) is 20.8 mL/day/kg, volume (V ss ) is 146 mL/kg, and bioavailability (F) of the SC dose dosing is 57.7%.

Abatacept (CTLA4lg) 是一种可溶性融合蛋白，由人 CTLA4 的胞外结构域和人 IgG1 Fc 部分的片段 (铰链，CH2 和 3 结构域) 组成。Abatacept 是选择性 T 细胞共刺激调节剂，也是一种用于自身免疫性疾病的蛋白药物。