Drugging the pharmacoresistant CaV2.3: From target validation to pre-clinical candidates

The pharmacoresistant (R-type) voltage-gated calcium channel (CaV2.3) is widely expressed in the brain and participates in multiple physiological processes in the central nervous system. Recent studies have revealed that dysfunction of CaV2.3 is involved in severe paediatric syndromes including DEE2 and DEE69. These genetic disorders are characterised by treatment-resistant forms of epilepsy, profound developmental delay, and movement difficulties. In addition to the forms abovementioned, there is significant evidence that modulation of this channel could help controlling seizures in various drug-refractory forms of epilepsy. Last but not least, studies have demonstrated that the deletion of CaV2.3 can protect against an
experimental form of Parkinson’s disease making this channel a promising target for different neurological disorders. Therefore, Axxam is supporting Lario Therapeutics efforts to discover first-in class CaV2.3 modulators. To do so, different cell lines (primary target and selectivity) were generated and electrophysiologically validated in Axxam. Subsequently, an HTS campaign was performed by screening over 50K lead-like compounds using a cellbased FLIPR assay as primary screening tool. Primary hits were confirmed and qualified on the same platform and then validated using the automated patch-clamp device: QPatch. Those active in the micromolar range were chosen as starting point for the subsequent hit-to-lead activities performed both on FLIPR and QPatch platforms. The effectiveness of the identified hits was also confirmed using manual patch clamp, and further studies were carried out on different isoforms and mutations.

Enabled by the promising results gained on Axxam’s different platforms, Lario Therapeutics is advancing its drug candidates rapidly towards the clinics.