Fig 2: OGTT in KKAy mice.(A) OGTT in KKAy mice at the beginning of the 4-week treatment period. Glucose (2 g/kg) was administered 30 min before injection of GLP-1-IgG2σ-Fc (1 mg/kg), GLP-1-IgG4-Fc (1 mg/kg), or saline (200 μL). The area under the curve (AUC) for the glucose levels is shown in the upper left panel. (B) OGTT in KKAy mice at the end of the 4-week treatment period. The AUC for the glucose levels is shown in the upper left panel. (C) Insulin levels were tested at 0 and 30 min during the OGTT test; *p < 0.05; **p < 0.01; ***p < 0.001 versus the vehicle-treated group.

Fig 3: Long-term pharmacodynamics.(A) Blood glucose was measured prior to the administration of the indicated treatments to KKAy mice every three days for 4 weeks. (B) The area under the curve (AUC) of the data presented in (A). (C) Mouse body weights were recorded every day. (D) Food intake of each group. *p < 0.05; **p < 0.01; ***p < 0.001, versus the vehicle-treated group; #p < 0.05, versus the GLP-1-IgG4-Fc-treated group.

Fig 4: Pharmacokinetics in cynomolgus monkeys.Plasma fusion protein levels were determined by ELISA following administration of 0.1 mg/kg GLP-1-IgG4-Fc.

Fig 5: Generation of the GLP-1-IgG2σ-Fc expression vector.(A) DNA encoding GLP-1-IgG2σ-Fc was synthesized and inserted into a mammalian expression vector, SGLs. (B) GLP-1-IgG2σ-Fc comprises a pair of human GLP-1 variants (A8G/G26E/R36G) and a human IgG2σ constant heavy-chain, with a molecular mass of 68 kDa. (C) SDS-PAGE analysis of cell culture medium indicated that stably transfected cells secreted the highest amount of GLP-1-IgG2σ-Fc on day 12. (D) Western blotting analysis confirmed that the expressed 68-kDa protein showed good antigenicity to both GLP-1 and human IgG.