6jt4

Publication Abstract from PubMed

The beta-site amyloid precursor protein cleaving enzyme 1 (BACE1, also known as beta-secretase) is a promising target for the treatment of Alzheimer's disease. A pK(a) lowering approach over the initial leads was adopted to mitigate hERG inhibition and P-gp efflux, leading to the design of 6-CF(3) dihydrothiazine 8 (N-(3-((4S,6S)-2-amino-4-methyl-6-(trifluoromethyl)-5,6-dihydro-4H-1,3-thiazin-4-yl)-4-fluorophenyl)-5-cyanopicolinamide). Optimization of 8 led to the discovery of 15 (N-(3-((4S,6S)-2-amino-4-methyl-6-(trifluoromethyl)-5,6-dihydro-4H-1,3-thiazin-4-yl)-4-fluorophenyl)-5-(fluoromethoxy)pyrazine-2-carboxamide) with an excellent balance of potency, hERG inhibition, P-gp efflux, and metabolic stability. Oral administration of 8 elicited robust Abeta reduction in dog even at 0.16 mg/kg. Reflecting the reduced hERG inhibitory activity, no QTc prolongation was observed at high doses. The potential for reactive metabolite formation of 15 was realized in a nucleophile trapping assay using [(14) C]-KCN in human liver microsomes. Utilizing covalent binding (CVB) in human hepatocytes and the maximum projected human dosage, the daily CVB burden of 15 was calculated to be at an acceptable value of below 1 mg/day. However, hepatotoxicity was observed when 15 was subjected to a two-week tolerance study in dog, which prevented further evaluation of this compound.

Trifluoromethyl Dihydrothiazine-Based beta-Secretase (BACE1) Inhibitors with Robust Central beta-Amyloid Reduction and Minimal Covalent Binding Burden.,Anan K, Iso Y, Oguma T, Nakahara K, Suzuki S, Yamamoto T, Matsuoka E, Ito H, Sakaguchi G, Ando S, Morimoto K, Kanegawa N, Kido Y, Kawachi T, Fukushima T, Teisman A, Urmaliya V, Dhuyvetter D, Borghys H, Austin N, Van Den Bergh A, Verboven P, Bischoff F, Gijsen HJM, Yamano Y, Kusakabe K ChemMedChem. 2019 Nov 20;14(22):1894-1910. doi: 10.1002/cmdc.201900478. Epub 2019 , Nov 12. PMID:31657130^[3]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.