Fragment-Based Discovery of MRTX1719, a Synthetic Lethal Inhibitor of the PRMT5•MTA Complex for the Treatment of MTAP -Deleted Cancers.
Smith, C.R., Aranda, R., Bobinski, T.P., Briere, D.M., Burns, A.C., Christensen, J.G., Clarine, J., Engstrom, L.D., Gunn, R.J., Ivetac, A., Jean-Baptiste, R., Ketcham, J.M., Kobayashi, M., Kuehler, J., Kulyk, S., Lawson, J.D., Moya, K., Olson, P., Rahbaek, L., Thomas, N.C., Wang, X., Waters, L.M., Marx, M.A.(2022) J Med Chem 65: 1749-1766
- PubMed: 35041419 
- DOI: https://doi.org/10.1021/acs.jmedchem.1c01900
- Primary Citation of Related Structures:  
7S0U, 7S1P, 7S1Q, 7S1R, 7S1S, 7SER, 7SES - PubMed Abstract: 
The PRMT5•MTA complex has recently emerged as a new synthetically lethal drug target for the treatment of MTAP -deleted cancers. Here, we report the discovery of development candidate MRTX1719 . MRTX1719 is a potent and selective binder to the PRMT5•MTA complex and selectively inhibits PRMT5 activity in MTAP -deleted cells compared to MTAP -wild-type cells. Daily oral administration of MRTX1719 to tumor xenograft-bearing mice demonstrated dose-dependent inhibition of PRMT5-dependent symmetric dimethylarginine protein modification in MTAP -deleted tumors that correlated with antitumor activity. A 4-(aminomethyl)phthalazin-1(2 H )-one hit was identified through a fragment-based screen, followed by X-ray crystallography, to confirm binding to the PRMT5•MTA complex. Fragment growth supported by structural insights from X-ray crystallography coupled with optimization of pharmacokinetic properties aided the discovery of development candidate MRTX1719 .
Organizational Affiliation: 
Mirati Therapeutics, San Diego, California 92121, United States.