Diabetic Cardiomyopathy (DbCM) leading to overt heart failure is a common sequelae of both type 1 and type 2 diabetes. Prior attempts to develop treatments for DbCM via inhibition of Aldose Reductase (AR) were unsuccessful, due to low AR binding affinity and off-target binding with Aldehyde Reductase (AldR), an enzyme critical for detoxification of aldehydes in the liver and normal hepatocyte function. This resulted in liver-related safety and tolerability issues with first generation ARIs. We report on the selectivity and specificity of AT-001, a novel small molecule ARI with optimized affinity and specificity for AR and minimal to zero off-target AldR activity.

Methods and Results: AT-001 was evaluated for AR binding affinity vs. zopolrestat, a prior best in class ARI, which had been challenged with liver toxicity issues in clinical development. AT-001 demonstrated logarithmically improved AR inhibitory activity (IC50 of 30 pmol for AT-001 and 10 nmol for zopolrestat). Liver enzyme evaluations demonstrated that AT-001 showed no inhibition of AldR at 50x and 100x EC50 levels in assay medium, while zopolrestat inhibited AldR by 50% and 60% respectively (spec activity of 2.3 and 1.9 mmol NADPH/min/mg prot.). Additionally no elevations of ALT/AST’s were observed with AT-001 at doses up to 50x EC50, in contrast to zopolrestat which showed dose dependent release of ALT and AST (consistent with hepatocyte damage and eventual cell death). Finally, AT-001 was evaluated in a standard off-target receptor binding analysis of 87 substrates (13 enzymes, 74 binding assays); with no significant results (>50% inhibitory activity) observed.

Conclusion: The unique structure and activity of AT-001 provide potent selectivity for Aldose Reductase and lack of off-target effects. The in-vitro safety of this agent together with the positive safety data from the phase 1/2 program, supports the ongoing pivotal study in DbCM.


R. Perfetti: Stock/Shareholder; Self; Applied Therapeutics. G. Yepuri: None. N.A. Quadri: None. A.F. Ghannam: Employee; Self; Applied Therapeutics Inc. Stock/Shareholder; Self; Sanofi US. R. Ramasamy: Consultant; Self; Applied Therapeutics. S. Shendelman: Employee; Self; Applied Therapeutics. Stock/Shareholder; Self; Applied Therapeutics.


Applied Therapeutics (NCT04083339)

Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. More information is available at http://www.diabetesjournals.org/content/license.