Discovery and In Vivo Efficacy of AZ-PRMT5i-1, a Novel PRMT5 Inhibitor with High MTA Cooperativity.
Smith, J.M., Barlaam, B., Beattie, D., Bradshaw, L., Chan, H.M., Chiarparin, E., Collingwood, O., Cooke, S.L., Cronin, A., Cumming, I., Dean, E., Debreczeni, J.E., Del Barco Barrantes, I., Diene, C., Gianni, D., Guerot, C., Guo, X., Guven, S., Hayhow, T.G., Hong, T., Kemmitt, P.D., Lamont, G.M., Lamont, S., Lynch, J.T., McWilliams, L., Moore, S., Raubo, P., Robb, G.R., Robinson, J., Scott, J.S., Srinivasan, B., Steward, O., Stubbs, C.J., Syson, K., Tan, L., Turner, O., Underwood, E., Urosevic, J., Vazquez-Chantada, M., Whittaker, A.L., Wilson, D.M., Winter-Holt, J.J.(2024) J Med Chem 67: 13604-13638
- PubMed: 39080842 
- DOI: https://doi.org/10.1021/acs.jmedchem.4c00097
- Primary Citation of Related Structures:  
9EYU, 9EYV, 9EYW, 9EYX - PubMed Abstract: 
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.
Organizational Affiliation: 
Research and Early Development, Oncology R&D, AstraZeneca, Cambridge CB2 0AA, United Kingdom.