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.
Gordhan, H.M., Miller, S.T., Clancy, D.C., Ina, M., McDougal, A.V., Cutno, D.K., Brown, R.V., Lichorowic, C.L., Sturdivant, J.M., Vick, K.A., Williams, S.S., deLong, M.A., White, J.C., Kopczynski, C.C., Ellis, D.A.(2023) J Med Chem 66: 8929-8950
- PubMed: 37314941 
- DOI: https://doi.org/10.1021/acs.jmedchem.3c00519
- Primary Citation of Related Structures:  
8G6Z, 8G8O, 8G8X - PubMed 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)-1 H -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 KINOME scan selectivity profile of 5 substantiated the likelihood of widespread series affinity across the human kinome. An sp 2 -to-sp 3 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 sp 3 (Fsp 3 ), and bolster molecular complexity led to the azetidin-3-amino bridging scaffold in 31 .
Organizational Affiliation: 
Alcon Research, LLC, Durham, North Carolina 27703, United States.