FGF21 analogs of sustained action enabled by orthogonal biosynthesis demonstrate enhanced antidiabetic pharmacology in rodents.
Fibroblast growth factor 21 (FGF21) mitigates many of the pathogenic features of type 2 diabetes, despite a short circulating half-life. PEGylation is a proven approach to prolonging the duration of action while enhancing biophysical solubility and stability. However, in the absence of a specific protein PEGylation site, chemical conjugation is inherently heterogeneous and commonly leads to dramatic loss in bioactivity. This work illustrates a novel means of specific PEGylation, producing FGF21 analogs with high specific activity and salutary biological activities. Using homology modeling and structure-based design, specific sites were chosen in human FGF21 for site-specific PEGylation to ensure that receptor binding regions were preserved. The in vitro activity of the PEGylated FGF21 ana-logs corresponded with the site of PEG placement within the binding model. Site-specific PEGylated analogs demonstrated dramatically increased circulating half-life and enhanced efficacy in db/db mice. Twice-weekly dosing of an optimal FGF21 analog reduced blood glucose, plasma lipids, liver triglycerides, and plasma glucagon and enhanced pancreatic insulin content, islet number, and glucose-dependent insulin secretion. Restoration of insulin sensitivity was demonstrated by the enhanced ability of insulin to induce Akt/protein kinase B phosphorylation in liver, muscle, and adipose tissues. PEGylation of human FGF21 at a specific and preferred site confers superior metabolic pharmacology.
Department of Metabolic Disease-Diabetes, Merck Research Laboratories, Rahway, New Jersey, USA.
James
J
Mu
Jason
J
Pinkstaff
Zhihua
Z
Li
Lillian
L
Skidmore
Nina
N
Li
Heather
H
Myler
Qing
Q
Dallas-Yang
Anna-Maria
AM
Putnam
Jun
J
Yao
Stuart
S
Bussell
Margaret
M
Wu
Thea C
TC
Norman
Carlos G
CG
Rodriguez
Bruce
B
Kimmel
Joseph M
JM
Metzger
Anthony
A
Manibusan
Darin
D
Lee
Dennis M
DM
Zaller
Bei B
BB
Zhang
Richard D
RD
DiMarchi
Joel P
JP
Berger
Douglas W
DW
Axelrod
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D003692:Delayed-Action Preparations; D004734:Energy Metabolism / Q000187:drug effects; D005346:Fibroblast Growth Factors / Q000096:biosynthesis / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology*; D057809:HEK293 Cells; D006801:Humans; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D007333:Insulin Resistance; D008297:Male; D051379:Mice; D011092:Polyethylene Glycols / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley
D003692:Delayed-Action Preparations; D007004:Hypoglycemic Agents; C414620:fibroblast growth factor 21; D011092:Polyethylene Glycols; D005346:Fibroblast Growth Factors