RESUMEN
BACKGROUND: Varoglutamstat (formerly PQ912) is a small molecule that inhibits the activity of the glutaminyl cyclase to reduce the level of pyroglutamate-A-beta (pGluAB42). Recent studies confirm that pGluAB42 is a particular amyloid form that is highly synaptotoxic and plays a significant role in the development of AD. METHODS: This paper describes the design and methodology behind the phase 2b VIVIAD-trial in AD. The aim of this study is to evaluate varoglutamstat in a state-of-the-art designed, placebo-controlled, double-blind, randomized clinical trial for safety and tolerability, efficacy on cognition, and effects on brain activity and AD biomarkers. In addition to its main purpose, the trial will explore potential associations between novel and established biomarkers and their individual and composite relation to disease characteristics. RESULTS: To be expected early 2023 CONCLUSION: This state of the art phase 2b study will yield important results for the field with respect to trial methodology and for the treatment of AD with a small molecule directed against pyroglutamate-A-beta. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04498650.
Asunto(s)
Enfermedad de Alzheimer , Aminoaciltransferasas , Método Doble Ciego , Humanos , Resultado del TratamientoAsunto(s)
Dipeptidil Peptidasa 4/metabolismo , Polipéptido Inhibidor Gástrico/metabolismo , Fragmentos de Péptidos/farmacología , Sustitución de Aminoácidos , Animales , Unión Competitiva , Células CHO , Cricetinae , AMP Cíclico/metabolismo , Diabetes Mellitus Tipo 2 , Diseño de Fármacos , Polipéptido Inhibidor Gástrico/química , Humanos , Hidrólisis , Fragmentos de Péptidos/síntesis química , Fragmentos de Péptidos/metabolismo , Ratas , Receptores de la Hormona Gastrointestinal/efectos de los fármacos , Receptores de la Hormona Gastrointestinal/genética , Receptores de la Hormona Gastrointestinal/metabolismo , Proteínas Recombinantes de Fusión/metabolismo , Sistemas de Mensajero Secundario/efectos de los fármacos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización DesorciónRESUMEN
Over the past decade, numerous studies have been targeted at defining structure-activity relationships of glucagon. Recently, we have found that glucagon(1-29) is hydrolyzed by dipeptidyl peptidase IV (DPIV) to produce glucagon(3-29) and glucagon(5-29); in human serum, [pyroglutamyl (pGlu)(3)]glucagon(3-29) is formed from glucagon(3-29), and this prevents further hydrolysis of glucagon by DPIV (H.-U. Demuth, K. Glund, U. Heiser, J. Pospisilik, S. Hinke, T. Hoffmann, F. Rosche, D. Schlenzig, M. Wermann, C. McIntosh, and R. Pederson, manuscript in preparation). In the current study, the biological activity of these peptides was examined in vitro. The amino-terminally truncated peptides all behaved as partial agonists in cyclic AMP stimulation assays, with Chinese hamster ovary K1 cells overexpressing the human glucagon receptor (potency: glucagon(1-29) > [pGlu(3)]glu- cagon(3-29) > glucagon(3-29) > glucagon(5-29) > [Glu(9)]glu- cagon(2-29)). In competition binding experiments, [pGlu(3)]glucagon(3-29) and glucagon(5-29) both demonstrated 5-fold lower affinity for the receptor than glucagon(1-29), whereas glucagon(3-29) exhibited 18-fold lower affinity. Of the peptides tested, only glucagon(5-29) showed antagonist activity, and this was weak compared with the classical glucagon antagonist, [Glu(9)]glucagon(2-29). Hence, DPIV hydrolysis of glucagon yields low affinity agonists of the glucagon receptor. As a corollary to evidence indicating that DPIV degrades glucagon (Demuth, et al., manuscript in preparation), DPIV-resistant analogs were synthesized. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry was used to assess DPIV resistance, and it allowed kinetic analysis of degradation. Of several analogs generated, only [D-Ser(2)] and [Gly(2)]glucagon retained high affinity binding and biological potency, similar to native glucagon in vitro. [D-Ser(2)]Glucagon exhibited enhanced hyperglycemic activity in a bioassay, whereas [Gly(2)]glucagon was not completely resistant to DPIV degradation.