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Updated: May 12, 2026
Screening and Identification of Small Peptides Targeting Fibroblast Growth Factor Receptor2 using a Phage Display Peptide Library
Published on: September 30, 2019
Rational design of a fibroblast growth factor 21-based clinical candidate, LY2405319
Alexei Kharitonenkov1, John M Beals, Radmila Micanovic
1Lilly Research Laboratories, Lilly Corporate Center, Indianapolis, Indiana, United States of America. a.kharch@lilly.com
Abstract:
Fibroblast growth factor 21 is a novel hormonal regulator with the potential to treat a broad variety of metabolic abnormalities, such as type 2 diabetes, obesity, hepatic steatosis, and cardiovascular disease. Human recombinant wild type FGF21 (FGF21) has been shown to ameliorate metabolic disorders in rodents and non-human primates. However, development of FGF21 as a drug is challenging and requires re-engineering of its amino acid sequence to improve protein expression and formulation stability. Here we report the design and characterization of a novel FGF21 variant, LY2405319. To enable the development of a potential drug product with a once-daily dosing profile, in a preserved, multi-use formulation, an additional disulfide bond was introduced in FGF21 through Leu118Cys and Ala134Cys mutations. FGF21 was further optimized by deleting the four N-terminal amino acids, His-Pro-Ile-Pro (HPIP), which was subject to proteolytic cleavage. In addition, to eliminate an O-linked glycosylation site in yeast a Ser167Ala mutation was introduced, thus allowing large-scale, homogenous protein production in Pichia pastoris. Altogether re-engineering of FGF21 led to significant improvements in its biopharmaceutical properties. The impact of these changes was assessed in a panel of in vitro and in vivo assays, which confirmed that biological properties of LY2405319 were essentially identical to FGF21. Specifically, subcutaneous administration of LY2405319 in ob/ob and diet-induced obese (DIO) mice over 7-14 days resulted in a 25-50% lowering of plasma glucose coupled with a 10-30% reduction in body weight. Thus, LY2405319 exhibited all the biopharmaceutical and biological properties required for initiation of a clinical program designed to test the hypothesis that administration of exogenous FGF21 would result in effects on disease-related metabolic parameters in humans.
Insights
Fibroblast growth factor 21 (FGF21) was engineered into LY2405319, a novel variant with improved stability and production. LY2405319 effectively ameliorates metabolic disorders, showing potential for treating type 2 diabetes and obesity.
Area of Science:
- Metabolic disorders
- Protein engineering
- Pharmacology
Background:
- Fibroblast growth factor 21 (FGF21) is a novel hormone regulator with therapeutic potential for metabolic abnormalities like type 2 diabetes, obesity, hepatic steatosis, and cardiovascular disease.
- Human recombinant wild-type FGF21 demonstrates efficacy in ameliorating metabolic disorders in preclinical models.
- Developing FGF21 as a drug faces challenges related to protein expression and formulation stability, necessitating sequence re-engineering.
Purpose of the Study:
- To design and characterize a novel FGF21 variant, LY2405319, with enhanced biopharmaceutical properties for potential drug development.
- To improve protein expression, formulation stability, and enable once-daily dosing of FGF21.
- To assess the in vitro and in vivo efficacy of the engineered FGF21 variant.
Main Methods:
- Introduction of an additional disulfide bond via Leu118Cys and Ala134Cys mutations to improve stability.
- Deletion of N-terminal His-Pro-Ile-Pro (HPIP) to prevent proteolytic cleavage.
- Ser167Ala mutation to eliminate O-linked glycosylation and facilitate homogenous protein production in Pichia pastoris.
- In vitro and in vivo assays to evaluate biopharmaceutical properties and biological activity.
Main Results:
- LY2405319 exhibited significantly improved biopharmaceutical properties compared to wild-type FGF21.
- In vitro and in vivo assays confirmed that LY2405319 retained the biological activity of FGF21.
- Subcutaneous administration in obese mouse models (ob/ob and DIO) resulted in significant reductions in plasma glucose (25-50%) and body weight (10-30%).
Conclusions:
- The engineered FGF21 variant, LY2405319, possesses favorable biopharmaceutical and biological properties.
- LY2405319 demonstrates efficacy in ameliorating key metabolic parameters in preclinical models of obesity and diabetes.
- These findings support the initiation of a clinical program to evaluate LY2405319 for treating metabolic diseases in humans.
