Eyes on Topical Ocular Disposition: The Considered Design of a Lead Janus Kinase (JAK) Inhibitor That Utilizes a Unique Azetidin-3-Amino Bridging Scaffold to Attenuate Off-Target Kinase Activity, While Driving Potency and Aqueous Solubility

J Med Chem. 2023 Jul 13;66(13):8929-8950. doi: 10.1021/acs.jmedchem.3c00519. Epub 2023 Jun 14.

Abstract

An unmet medical need remains for patients suffering from dry eye disease (DED). A fast-acting, better-tolerated noncorticosteroid anti-inflammatory eye drop could improve patient outcomes and quality of life. Herein, we describe a small-molecule drug discovery effort to identify novel, potent, and water-soluble JAK inhibitors as immunomodulating agents for topical ocular disposition. A focused library of known 3-(4-(2-(arylamino)pyrimidin-4-yl)-1H-pyrazol-1-yl)propanenitriles was evaluated as a molecular starting point. Structure-activity relationships (SARs) revealed a ligand-efficient (LE) JAK inhibitor series, amenable to aqueous solubility. Subsequent in vitro analysis indicated the potential for off-target toxicity. A KINOMEscan selectivity profile of 5 substantiated the likelihood of widespread series affinity across the human kinome. An sp2-to-sp3 drug design strategy was undertaken to attenuate off-target kinase activity while driving JAK-STAT potency and aqueous solubility. Tactics to reduce aromatic character, increase fraction sp3 (Fsp3), and bolster molecular complexity led to the azetidin-3-amino bridging scaffold in 31.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Humans
  • Janus Kinase 1
  • Janus Kinase 2
  • Janus Kinase 3
  • Janus Kinase Inhibitors* / pharmacology
  • Janus Kinases
  • Phosphorylation
  • Protein Kinase Inhibitors / pharmacology
  • Solubility

Substances

  • Janus Kinase 1
  • Janus Kinase 2
  • Janus Kinase 3
  • Janus Kinase Inhibitors
  • Janus Kinases
  • Protein Kinase Inhibitors