PF-05231023

FGF21 suppresses alcohol consumption through an amygdalo-striatal circuit

Excessive alcohol consumption is a major health and social issue in our society. Pharmacologic administration of the endocrine hormone fibroblast growth factor 21 (FGF21) suppresses alcohol consumption through actions in the brain in rodents, and genome-wide association studies have identified single nucleotide polymorphisms in genes involved with FGF21 signaling as being associated with increased alcohol consumption in humans. However, the neural circuit(s) through which FGF21 signals to suppress alcohol consumption are unknown, as are its effects on alcohol consumption in higher organisms. Here, we demonstrate that administration of an FGF21 analog to alcohol-preferring non-human primates reduces alcohol intake by 50%. Further, we reveal that FGF21 suppresses alcohol consumption through a projection-specific subpopulation of KLB-expressing neurons in the basolateral amygdala. Our results illustrate how FGF21 suppresses alcohol consumption through a specific population of neurons in the brain and demonstrate its therapeutic potential in non-human primate models of excessive alcohol consumption.

PF-05231023, a long-acting FGF21 analogue, decreases body weight by reduction of food intake in non-human primates

PF-05231023, a long-acting FGF21 analogue, is a promising potential pharmacotherapy for the treatment of obesity and associated comorbidities. Previous studies have shown the potential of FGF21 and FGF21-like compounds to decrease body weight in mice, non-human primates, and humans; the precise mechanisms of action remain unclear. In particular, there have been conflicting reports on the degree to which FGF21-induced weight loss in non-human primates is attributable to a decrease in food intake versus an increase in energy expenditure. Here, we present a semi-mechanistic mathematical model of energy balance and body composition developed from similar work in mice. This model links PF-05231023 administration and washout to changes in food intake, which in turn drives changes in body weight. The model is calibrated to and compared with recently published data from cynomolgus macaques treated with PF-05231023, demonstrating its accuracy in describing pharmacotherapy-induced weight loss in these animals. The results are consistent with the hypothesis that PF-05231023 decreases body weight in cynomolgus macaques solely by a reduction in food intake, with no direct effect on energy expenditure.

Pharmacokinetics and pharmacodynamics of PF-05231023, a novel long-acting FGF21 mimetic, in a first-in-human study

Aims: The aim of the present study was to evaluate the pharmacokinetics/pharmacodynamics (PK/PD), safety and tolerability of single intravenous (IV) doses of PF-05231023, a long acting fibroblast growth factor 21 (FGF21) analogue being developed for the treatment of type 2 diabetes mellitus (T2DM).
Methods: T2DM subjects (glycosylated haemoglobin: 7.0-10.5%; on stable metformin therapy and/or diet and exercise) were randomized to receive a single dose of placebo or PF-05231023 (0.5-200 mg). Safety evaluations were performed up to 14 days after dosing. PK and PD endpoints were measured and a PK/PD model was developed for triglyceride - an early marker of drug activity.
Results: No antidrug antibody or serious adverse events (AEs) were observed. The most frequent AEs were gastrointestinal but were generally mild. Plasma PF-05231023 levels peaked immediately post-IV dosing, with mean terminal half-lives of 6.5-7.7 h and 66.5- 96.6 h for intact C- and N-termini, respectively. Intact C-terminus exposures increased proportionally with increasing dose, whereas N-terminus exposures appeared to trend higher than dose-proportionally. Although no apparent effect on plasma glucose was seen, dose-dependent decreases in triglyceride were observed, with a maximum reduction of 48.5 ± 10.0% (mean ± standard deviation) for the 200 mg dose compared with a reduction of 19.1 ± 26.4% for placebo, demonstrating proof of pharmacology. Moreover, a reduction in total cholesterol and low-density lipoprotein cholesterol and an increase in high-density lipoprotein cholesterol were observed in the high-dose groups.
Conclusions: Single IV doses of PF-05231023 up to 200 mg were generally safe and well tolerated by subjects with T2DM. The observed early sign of pharmacology supports further clinical testing of PF-05231023 upon repeated administration.

A Long-Acting FGF21 Molecule, PF-05231023, Decreases Body Weight and Improves Lipid Profile in Non-human Primates and Type 2 Diabetic Subjects

FGF21 plays a central role in energy, lipid, and glucose homeostasis. To characterize the pharmacologic effects of FGF21, we administered a long-acting FGF21 analog, PF-05231023, to obese cynomolgus monkeys. PF-05231023 caused a marked decrease in food intake that led to reduced body weight. To assess the effects of PF-05231023 in humans, we conducted a placebo-controlled, multiple ascending-dose study in overweight/obese subjects with type 2 diabetes. PF-05231023 treatment resulted in a significant decrease in body weight, improved plasma lipoprotein profile, and increased adiponectin levels. Importantly, there were no significant effects of PF-05231023 on glycemic control. PF-05231023 treatment led to dose-dependent changes in multiple markers of bone formation and resorption and elevated insulin-like growth factor 1. The favorable effects of PF-05231023 on body weight support further evaluation of this molecule for the treatment of obesity. Longer studies are needed to assess potential direct effects of FGF21 on bone in humans.

Mechanistic investigation of the preclinical pharmacokinetics and interspecies scaling of PF-05231023, a fibroblast growth factor 21-antibody protein conjugate

PF-05231023, a long-acting fibroblast growth factor 21 (FGF21) analog, was generated by covalently conjugating two engineered [des-His1, Ala129Cys]FGF21 molecules to a nontargeting human IgG1 κ scaffold. The pharmacokinetics (PK) of PF-05231023 after i.v. and s.c. administration was evaluated in rats and monkeys using two enzyme-linked immunosorbent assays with high specificity for biologically relevant intact N termini (NT) and C termini (CT) of FGF21. Intact CT of FGF21 displayed approximately 5-fold faster systemic plasma clearance (CL), an approximately 2-fold lower steady-state volume of distribution, and at least 5-fold lower bioavailability compared with NT. In vitro serum stability studies in monkeys and humans suggested that the principal CL mechanism for PF-05231023 was degradation by serum proteases. Direct scaling of in vitro serum degradation rates for intact CT of FGF21 underestimated in vivo CL 5-fold, 1.4-fold, and 2-fold in rats, monkeys, and humans, respectively. The reduced steady-state volume of distribution and the bioavailability for intact CT relative to NT in rats and monkeys were compatible with proteolytic degradation occurring outside the plasma compartment via an unidentified mechanism. Human CL and PK profiles for intact NT and CT of FGF21 were well predicted using monkey single-species allometric and Dedrick scaling. Physiologically based pharmacokinetic models incorporating serum stability data and an extravascular extraction term based on differential bioavailability of intact NT and CT of FGF21 in monkeys improved accuracy of human PK predictions relative to Dedrick scaling. Mechanistic physiologically based pharmacokinetic models of this nature may be highly valuable for predicting human PK of fusion proteins, synthetically conjugated proteins, and other complex biologics.