Discovery and Characterization of 2-Acylaminoimidazole Microsomal Prostaglandin E Synthase-1 Inhibitors

  • J Med Chem. 2016 Jan 14;59(1):194-205. doi: 10.1021/acs.jmedchem.5b01249.
Matthew A Schiffler  1 Stephen Antonysamy  2 Shobha N Bhattachar  1 Kristina M Campanale  1 Srinivasan Chandrasekhar  1 Bradley Condon  2 Prashant V Desai  1 Matthew J Fisher  1 Christopher Groshong  2 Anita Harvey  1 Michael J Hickey  2 Norman E Hughes  1 Scott A Jones  1 Euibong J Kim  1 Steven L Kuklish  1 John G Luz  2 Bryan H Norman  1 Richard E Rathmell  3 John R Rizzo  1 Thomas W Seng  1 Stefan J Thibodeaux  1 Timothy A Woods  1 Jeremy S York  1 Xiao-Peng Yu  1
Affiliations
  • 1. Lilly Research Laboratories, A Division of Eli Lilly and Company , Indianapolis, Indiana 46285, United States.
  • 2. Eli Lilly Biotechnology Center , San Diego, California 92121, United States.
  • 3. Lilly Research Laboratories, A Division of Eli Lilly and Company , Windlesham, Surrey GU20 6PH, United Kingdom.
Abstract

As part of a program aimed at the discovery of antinociceptive therapy for inflammatory conditions, a screening hit was found to inhibit microsomal prostaglandin E synthase-1 (mPGES-1) with an IC50 of 17.4 μM. Structural information was used to improve enzyme potency by over 1000-fold. Addition of an appropriate substituent alleviated time-dependent Cytochrome P450 3A4 (CYP3A4) inhibition. Further structure-activity relationship (SAR) studies led to 8, which had desirable potency (IC50 = 12 nM in an ex vivo human whole blood (HWB) assay) and absorption, distribution, metabolism, and excretion (ADME) properties. Studies on the formulation of 8 identified 8·H3PO4 as suitable for clinical development. Omission of a lipophilic portion of the compound led to 26, a readily orally bioavailable inhibitor with potency in HWB comparable to celecoxib. Furthermore, 26 was selective for mPGES-1 inhibition versus Other mechanisms in the prostanoid pathway. These factors led to the selection of 26 as a second clinical candidate.

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