The Fc-Fusion Approach to Weekly Dosing

Dulaglutide achieves its week-long duration differently from semaglutide. Instead of a fatty-acid side chain that binds albumin, dulaglutide fuses GLP-1 analog molecules to a modified human IgG4 Fc fragment — the same kind of stable protein scaffold used in many biologic drugs.

The Fc fusion protects the peptide from clearance and gives it a ~5-day half-life. The REWIND trial then established cardiovascular benefit in type 2 diabetes. This thread covers the engineering and the outcomes data.