Article
Author: Collingwood, Olga ; Smith, James M. ; Kemmitt, Paul D. ; Urosevic, Jelena ; Wilson, David M ; Winter-Holt, Jon J ; Cumming, Iain ; Robb, Graeme R. ; Whittaker, Amy L ; Vazquez-Chantada, Mercedes ; Debreczeni, Judit É ; Tan, Lixiang ; Hayhow, Thomas G. ; Lamont, Gillian M ; Cooke, Sophie L ; Syson, Karl ; Bradshaw, Lauren ; McWilliams, Lisa ; Moore, Shaun ; Lamont, Gillian M. ; Scott, James S. ; Underwood, Elizabeth ; Wilson, David M. ; Robinson, James ; Cronin, Anna ; Lamont, Scott ; Kemmitt, Paul D ; Steward, Oliver ; Robb, Graeme R ; Stubbs, Christopher J. ; Guerot, Carine ; Chiarparin, Elisabetta ; Beattie, David ; Chan, Ho Man ; Whittaker, Amy L. ; Raubo, Piotr ; Debreczeni, Judit É. ; Stubbs, Christopher J ; Guo, Xiaoxiao ; Hayhow, Thomas G ; Srinivasan, Bharath ; Lynch, James T. ; Cooke, Sophie L. ; Del Barco Barrantes, Iván ; del Barco Barrantes, Iván ; Lynch, James T ; Gianni, Davide ; Barlaam, Bernard ; Diene, Coura ; Scott, James S ; Winter-Holt, Jon J. ; Guven, Sinem ; Smith, James M ; Dean, Emma ; Turner, Oliver ; Hong, Ted
PRMT5, a type 2 arginine methyltransferase, has a critical role in regulating cell growth and survival in cancer. With the aim of developing MTA-cooperative PRMT5 inhibitors suitable for MTAP-deficient cancers, herein we report our efforts to develop novel "MTA-cooperative" compounds identified through a high-throughput biochemical screening approach. Optimization of hits was achieved through structure-based design with a focus on improvement of oral drug-like properties. Bioisosteric replacement of the original thiazole guanidine headgroup, spirocyclization of the isoindolinone amide scaffold to both configurationally and conformationally lock the bioactive form, and fine-tuning of the potency, MTA cooperativity, and DMPK properties through specific substitutions of the azaindole headgroup were conducted. We have identified an orally available in vivo lead compound, 28 ("AZ-PRMT5i-1"), which shows sub-10 nM PRMT5 cell potency, >50-fold MTA cooperativity, suitable DMPK properties for oral dosing, and significant PRMT5-driven in vivo efficacy in several MTAP-deficient preclinical cancer models.