In vitro and in vivo proof-of-concept studies of extracellular protein degradation using novel M6PR-targeting chimeras (MTACs).

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Presentation Time: 03:15 PM - 04:30 PM
Poster Board Number: B848
Abstract ID: 6012

Presenting Author:
Lisa Molz , VP Research at Avilar Therapeut.

Abstract:

The mannose-6-phosphate-receptor (M6PR) traffics proteins from extracellular and intracellular locales to late endosomes/lysosomes for degradation and is ubiquitously expressed. This natural endogenous function of the mannose-6-phosphate-receptor (M6PR) may be harnessed for degradation of soluble circulating proteins and cell specific degradation of membrane proteins. 

Here we describe the design and development of novel M6PR targeting chimeras (MTACs). MTACs are heterobifunctional molecules containing Avilar’s novel, potent, small molecule M6PR-binding ligands conjugated to ligands that bind a target protein of interest for degradation. For proof-of-concept studies, MTACs were designed to target the extracellular protein IgG, the second most abundant circulating protein with a long plasma half-life. Reduction of pathogenic IgG autoantibodies is a clinically validated strategy for treating multiple debilitating autoimmune diseases. In vitro characterization of tridentate and monodentate MTACs revealed potent biochemical binding to M6PR and IgG, and MTAC-mediated cellular uptake and degradation of IgG via the endolysosomal pathway in K562 and LNCaP cells. In vivo MTAC-mediated depletion of human IgG was demonstrated using a heterologous rat PK/PD model.