Discovery of the First Selective Nanomolar Inhibitors of ERAP2 by Kinetic Target‐Guided Synthesis

Abstract

Endoplasmic reticulum aminopeptidase 2 (ERAP2) is a key enzyme involved in the trimming of antigenic peptides presented by Major Histocompatibility Complex class I. It is a target of growing interest for the treatment of autoimmune diseases and in cancer immunotherapy. However, the discovery of potent and selective ERAP2 inhibitors is highly challenging. Herein, we have used kinetic target‐guided synthesis (KTGS) to identify such inhibitors. Co‐crystallization experiments revealed the binding mode of three different inhibitors with increasing potency and selectivity over related enzymes. Selected analogues engage ERAP2 in cells and inhibit antigen presentation in a cellular context. 4 d (BDM88951) displays favorable in vitro ADME properties and in vivo exposure. In summary, KTGS allowed the discovery of the first nanomolar and selective highly promising ERAP2 inhibitors that pave the way of the exploration of the biological roles of this enzyme and provide lead compounds for drug discovery efforts.

ERAP Inhibitors in Autoimmunity and Immuno-Oncology: Medicinal Chemistry Insights

“…Kinetic target -guided synthesis was used to discover the first nanomolar selective ERAP2 inhibitors from 6 dual azide/hydroxamic acid warheads, targeting the zinc ion in the catalytic site and 175 diverse alkynes . In this experiment, ERAP2 catalyzed the irreversible 1,3-dipolar cycloaddition between azides and diverse alkynes sufficiently bound to ERAP2, in the right configuration and proximity, to provide 19 triazole hits . They showed dose–response inhibition of ERAP2, either as a 1,4-/1,5-triazole mixture or as defined regioisomers.…”

Nilabh Shastri – Towards understanding classical and non-classical MHC-I antigen processing and presentation

“…Nilabh Shastri's contributions influenced discoveries of immune checkpoint inhibitor mechanisms of action, MHC cryptic epitopes and neoantigens and the relevance of mutations in ERAAP and other components of the MHC antigen processing machinery [25,10,13]. One legacy that will emerge from his work and contributions to the field is the development of ERAP1 and ERAP2 selective inhibitors that are expected to enter the clinic for MHC-I neoepitope modulation in the context of immunooncology therapy [18,4,20]. Nilabh Shastri's influence has been widely recognised [13,2], and he will be greatly missed as a college and immunologist.…”

Going beyond Binary: Rapid Identification of Protein–Protein Interaction Modulators Using a Multifragment Kinetic Target-Guided Synthesis Approach

“…Thus far, KTGS has mainly been utilized to identify enzyme inhibitors. Such targets include acetylcholinesterase, carbonic anhydrase, HIV-1 protease, and other enzymes . Although limited, KTGS reports on non-enzymatic targets have also been described, including those that involve targeting biomolecules such as DNA and RNA .…”

“…Such targets include acetylcholinesterase, carbonic anhydrase, HIV-1 protease, and other enzymes. 9 Although limited, KTGS reports on non-enzymatic targets have also been described, including those that involve targeting biomolecules such as DNA and RNA. 10 The ligation chemistry utilized in the vast majority of these reports is the Huisgen cycloaddition reaction between alkynes and azides to form 1,2,3-triazoles.…”