Development of a Long-Acting Insulin Analog Using Albumin Fusion Technology

Abstract

The primary therapeutic goal for the treatment of diabetes is maintenance of a long-term, near-normoglycemic condition and prevention of the onset or progression of the complications associated with the disease. Although several analogs of human insulin have been developed, the currently prescribed long-acting insulin analogs do not provide a stable basal glycemia for more than a few hours. Here, we report the development of Albulin, a long-acting insulin analog obtained by direct gene fusion of a singlechain human insulin to human serum albumin. Albulin showed an elimination t 1/2 of ϳ7 h in normoglycemic mice. In vitro pharmacodynamic profiles for Albulin characterized by receptor binding, inhibition of gluconeogenesis, induction of glucose uptake, and global regulation of gene expression in relevant cell types showed that Albulin produced similar activity profiles compared with that of recombinant human insulin. A single Albulin administration in vivo normalized blood glucose level in diabetic mice in a relatively peakless and sustained (24-h) fashion. A further reduction in glucose levels was achieved by administering a recombinant human insulin a few hours after Albulin injection in mice, indicating the potential for Albulin therapy in combination with available fast-acting insulin derivatives. In summary, Albulin displays characteristics of a potent long-acting insulin analog that can be evaluated for use as a novel insulin therapy for patients with insulin-dependent diabetes. Diabetes 54:251-258, 2005

Improved Pharmacokinetics of Recombinant Bispecific Antibody Molecules by Fusion to Human Serum Albumin

“…Thus, RSA had a t1 ⁄2 ␣ ϭ 4.1 h and a t1 ⁄2 ␤ ϭ 49.1 h, whereas HSA had a t1 ⁄2 ␣ ϭ 0.8 h (48 min) and a t1 ⁄2 ␤ ϭ 14.8 h. Our HSA fusion proteins showed similar or even better values in mice with t1 ⁄2 ␣ between 37 and 117 min and a t1 ⁄2 ␤ between 40 and 47 h indicating that the antibody fusion part (probably through increase in size of the fusion protein) also contributes to prolonged circulation time. This finding is in accordance with results of various other HSA fusion proteins, which showed improved pharmacokinetic properties in various animals including mice (25,(27)(28)(29). In addition, improved therapeutic activities were observed for HSA fusion proteins (25)(26)(27)(28).…”

“…Moreover, HSA has also been successfully used to generate fusion proteins, e.g. with hormones (insulin, human growth hormone) (25,26) and cytokines (interferon-␣, interferon-␤, IL-2) (27)(28)(29), to reduce immunogenicity and modulate the pharmacokinetic properties, thus improving therapeutic efficacy of these molecules. Improved pharmacokinetic properties have also been described for a scFv-HSA fusion protein as well as for F(abЈ) and F(abЈ) 2 conjugated to rat serum albumin (RSA) for the targeting of human tumor necrosis factor (20).…”

A Cocaine Hydrolase Engineered from Human Butyrylcholinesterase Selectively Blocks Cocaine Toxicity and Reinstatement of Drug Seeking in Rats

“…To obtain a form of CocH that might be developed as a protein therapeutic, we fused this recombinant BChE at its C terminus with human serum albumin. Similar fusion proteins have been observed to possess favorable pharmacokinetic properties with high stability and extended plasma half lives (Duttaroy et al, 2005). In work that is being reported elsewhere (Gao and Brimijoin, unpublished results), we observed that the mutant BChE-albumin fusion, 'Albu-CocH' retains high catalytic efficiency with cocaine (k cat ¼ 2700 min À1 , K m ¼ 2 mM) and exhibits a plasma half-life of 8 h after i.v.…”

Separation of Fast from Slow Anabolism by Site-specific PEGylation of Insulin-like Growth Factor I (IGF-I)

“…Interestingly, despite the postulated close interaction of the two insulin binding sites within the InsR, a fusion protein between insulin and albumin (albulin) is also equipotent to wild-type insulin both in vitro and in vivo (41).…”