New cardiac safety testing guidelines are being finalised, as part of the FDA’s Comprehensive in vitro Proarrhythmia Assay (CiPA) initiative, which aim to remove the over-reliance on screening against the hERG channel by expanding the panel to include hNav1.5, hCav1.2, hKv4.3/KChiP2.2, hKir2.1 and hKv7.1/KCNE1 human cardiac ion channels. In addition, the CiPA working groups have recently identified two additional in vitro assays required for in silico models to reliably predict proarrhythmia. The first is a ‘late’ sodium current assay, as inhibition of persistent inward current can affect repolarisation and mitigate proarrhythmia (e.g. ranolazine). The second assay quantifies the degree of drug trapping in the hERG channel using the Milnes voltage protocol, which can improve the prediction of proarrhythmic risk.
The presence of sensory neuron markers, excitability properties consistent with sensory neurons, and evidence of nociceptor ion channels (using both RNASeq and electrophysiology) provides strong evidence that iCell Sensory Neurons have a robust sensory neuron phenotype suitable for supporting pain discovery programs.
Using automated patch clamp technology, we evaluate the potency and selectivity of ten Nav1.7-selective arachnid peptide toxins, which have been fused to the C-terminus (Fc region) of human IgG1.