The screening work plan allows for the progression of a defined number of compounds into in vivo pharmaco-kinetics and the evaluation of promising candidate compounds in efficacy studies in a diabetes-induced obesity animal model.

The screening effort progressed through stages including:

• Structure-based virtual screening. The purpose of which is to employ structure-based virtual screening methods to select approximately 500 compounds capable of inhibiting Fyn-kinase from a broad diversity set.
• Purity analysis and IC50 determination of Fyn-kinase hits. To perform verification and validation of active compounds (IC50 determination) as well as to determine purity of selected active compounds by LC-MS analysis.
• Hit expansion. To select 2,000 structurally related compounds, which will be screened in the primary assay, and perform validation of actives (IC50 determination, up to 200 compounds), plus determine the purity of all compounds progressed to potency determination by LC-MS analysis.
• Active-to-hit studies. The goal is to deliver at least two distinct chemical series suitable for progression into a hit-to-lead phase.
• Hit identification phase. Resulted in 116 compounds spread over five SFK (sarc family kinase) chemical series libraries that are effective at inhibiting Fyn kinase and are thus effective at activating the target LKB-1 AMPK pathway.

This screening process has led us to add an important extra step to the current project that will significantly advance progress to a viable commercial product. We have completed two discrete selectivity screenings for fyn kinase versus other members of the SFK family.