Structure-Based Design of an Iminoheterocyclic beta-Site Amyloid Precursor Protein Cleaving Enzyme (BACE) Inhibitor that Lowers Central A beta in Nonhuman Primates.Mandal, M., Wu, Y., Misiaszek, J., Li, G., Buevich, A., Caldwell, J.P., Liu, X., Mazzola, R.D., Orth, P., Strickland, C., Voigt, J., Wang, H., Zhu, Z., Chen, X., Grzelak, M., Hyde, L.A., Kuvelkar, R., Leach, P.T., Terracina, G., Zhang, L., Zhang, Q., Michener, M.S., Smith, B., Cox, K., Grotz, D., Favreau, L., Mitra, K., Kazakevich, I., McKittrick, B.A., Greenlee, W., Kennedy, M.E., Parker, E.M., Cumming, J.N., Stamford, A.W.
(2016) J Med Chem 59: 3231-3248
- PubMed: 26937601
- DOI: https://doi.org/10.1021/acs.jmedchem.5b01995
- Primary Citation of Related Structures:
5HD0, 5HDU, 5HDV, 5HDX, 5HDZ, 5HE4, 5HE5, 5HE7
- PubMed Abstract:
We describe successful efforts to optimize the in vivo profile and address off-target liabilities of a series of BACE1 inhibitors represented by 6 that embodies the recently validated fused pyrrolidine iminopyrimidinone scaffold. Employing structure-based design, truncation of the cyanophenyl group of 6 that binds in the S3 pocket of BACE1 followed by modification of the thienyl group in S1 was pursued. Optimization of the pyrimidine substituent that binds in the S2'-S2″ pocket of BACE1 remediated time-dependent CYP3A4 inhibition of earlier analogues in this series and imparted high BACE1 affinity. These efforts resulted in the discovery of difluorophenyl analogue 9 (MBi-4), which robustly lowered CSF and cortex Aβ40 in both rats and cynomolgus monkeys following a single oral dose. Compound 9 represents a unique molecular shape among BACE inhibitors reported to potently lower central Aβ in nonrodent preclinical species.
Department of Global Chemistry, ‡Department of Neuroscience, §Department of Safety Assessment and Laboratory Animal Research, ∥Department of Discovery Pharmaceutical Sciences, and ⊥Department of Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, Merck Research Laboratories , 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, United States.