Albiglutide

Overview

Albiglutide was a once-weekly GLP-1 receptor agonist marketed as Tanzeum in the United States and Eperzan in Europe by GlaxoSmithKline. Approved by the FDA in 2014 for the treatment of type 2 diabetes, it was voluntarily withdrawn from the global market in 2018 for commercial reasons rather than safety or efficacy concerns. Despite its discontinuation, albiglutide remains clinically and scientifically relevant for its unique recombinant fusion architecture, which linked a GLP-1 analog tandemly to human serum albumin to achieve a multi-day half-life.

Albiglutide is related to other approved GLP-1 agonists including exenatide, liraglutide, lixisenatide, dulaglutide, and semaglutide.

Structure / Sequence

Albiglutide is a recombinant fusion protein consisting of two tandem copies of a modified human GLP-1 (residues 7-36) peptide genetically fused to the N-terminus of human serum albumin. The GLP-1 portion features an Ala8Gly substitution to resist DPP-4 degradation. The full-length protein is approximately 73 kDa, much larger than peptide-only analogs, and is produced in Saccharomyces cerevisiae.

Mechanism of Action

Albiglutide activates the GLP-1 receptor, stimulating glucose-dependent insulin secretion, suppressing glucagon, delaying gastric emptying, and reducing appetite. Fusion to albumin both prevents renal filtration and leverages FcRn-mediated recycling to markedly extend circulating half-life, supporting once-weekly dosing. Its lower receptor affinity relative to exendin-based analogs produces somewhat more modest HbA1c reductions and weight loss than liraglutide or semaglutide.

Research Summary

Notably, HARMONY Outcomes demonstrated cardiovascular benefit, reinforcing the GLP-1 class effect on major adverse cardiac events.

Pharmacokinetics

Albiglutide has a terminal half-life of approximately 5 days, enabling once-weekly dosing. Steady-state is reached after 4 to 5 weeks. Elimination is primarily through proteolytic degradation of the albumin fusion. The drug showed minimal renal clearance implications, a convenience in chronic kidney disease patients where peptide-based GLP-1 agonists must be adjusted.

Dosing Protocols

(Historical, for reference; albiglutide is no longer marketed.)

• Initiation: 30 mg subcutaneously once weekly
• Maintenance: 30 or 50 mg subcutaneously once weekly
• Administration: Abdomen, thigh, or upper arm; reconstitution from lyophilized powder required
• Renal impairment: No dose adjustment

Common Discussion Topics

• Reasons for market withdrawal despite cardiovascular benefit in HARMONY Outcomes
• Comparative efficacy against liraglutide and dulaglutide
• Unique albumin fusion platform as a design template for other long-acting biologics
• Injection-site reactions reported more frequently than with smaller peptide GLP-1 agonists
• Implications of discontinuation for research on albumin-fusion drug delivery

Related Compounds

• Exenatide — original GLP-1 agonist
• Liraglutide — daily GLP-1 agonist
• Lixisenatide — daily GLP-1 agonist
• Dulaglutide — weekly GLP-1 agonist (Fc fusion)
• Semaglutide — weekly GLP-1 agonist
• Tirzepatide — GLP-1/GIP dual agonist
• Retatrutide — triple agonist