Development of highly selective therapeutics targeting NaV channel subtypes for the non-opioid treatment of pain

Project Summary Abstract Abilita Bioan innovation driven biotechnology companyis seeking SBIR Phase I funding for the discovery of novel therapeutic antibodies targeting the human voltage gated sodiumNavchannels Navand Navfor the non opioid treatment of painNearlymillion adults in the US suffer from chronic painwhich results an estimated combined burden that exceeds $billion annually and eclipses the combined economic costs of diabetesheart disease and cancerThe prevalence of chronic pain lies at the root of an ongoing epidemic of prescription painkiller abuseCurrent pain management strategies rely heavily on the prescription of opioids as oxycodone and hydrocodonewhich are effectivebut are associated with an intrinsic risk of addiction and potentially fatal side effects like respiratory depressionSelect members of the human Nav channel family are critically involved in the sensation of pain and are expressed almost exclusively in the peripheral nervous systemThe discovery and development of specific Nav channel antagonists is considered to be a strategy with great potential for treatment of chronic pain and may have further applications to neuropathic and cancer painDespite the importance of subtype selectivity to both efficacy and safetycurrent Nav channel targeting drugs are poorly selective among the subtypesTo improve overall clinical efficacy and remove the potentially devastating side effects of Navtargeting drugs such as cardiac toxicitywe propose to develop subtype specific antibody based therapeuticsTo datethe challenges associated with the discovery of antibodies targeting ion channels are insurmountableThe main reasons for the lack of therapeutic antibodies or otherantibody likeagents targeting Nav channels are their very low expressionmembrane extractability and stability when removed from their natural membrane environmentAbilita Bio s directed evolution based discovery engine offers an innovative solution to this difficulty through the generation of Nav variants representing structurally and functionally enhanced versions of natural channels with unprecedented expression levels and improved thermostabilityWe call these variants Enabled Membrane ProteinsEMPsThe availability of highly expressing stable and functionally folded EMPswill enable the isolation of novel therapeutic antibodies using a combination of in vivo and in vitro antibody discovery methods as described more in detail in the proposalThe use of therapeutic antibody fragments to target human Nav channel family would have a tremendous potential for the treatment of pain because of their typical high affinityexquisite specificity and low toxicity relative to small molecule therapeuticsNav channel antibody orantibody likeantagonists can possibly represent a strategy for the safe treatment of chronic pain and may have further applications to neuropathic and cancer painFunds are requested toagenerate additional mutational gene libraries for proposed targets Navand Navand select for enhanced EMPvariants using our directed evolution discovery enginebcharacterize the selected EMPsvariants for expressionfunction and enhanced stability when produced from mammalian cells and confirm their relevant structure folding using tool compound bindingcselect the best candidate Navor NavEMPproduce it in large scale and use it for single domain antibody discoverynanobodyusing a phage display platformdlastlythe discovered monovalent or dimerized antibody hits will be tested for relevant pharmacology using whole cell electrophysiology studiespatch clampin order to determine the functional inhibition of Nav channel activity Project Narrative To datethe challenges associated with the discovery of antibodies targeting ion channels are insurmountableThe proposed study focuses on addressing technical hurdles that have so far limited the ability to produce appropriate amounts of well folded and stable human voltage gated sodiumNavchannels to be used as whole protein antigensSuch tools are critically needed to enable Nav specific therapeutic antibody discovery and development against the subtypes Navand Navwhich are validated targets for non opioid pain treatmentAbilita Bio s unique approachwhich is based on directed evolution to obtain radically improved variants of the natural Nav targets that we call EMPsTMEnabled Membrane Proteinshas allowed us to identify Navand Navvariants of unprecedented expression levelsIn characterization of these preliminary EMPsTMwe have determined that the purified channel variants are still assembled and reached reasonable levels of stability and homogeneityImportantlypreliminary measurements using Surface Plasmon Resonance have demonstrated that our EMPsTM are well foldedas suggested by their capability to bind the toxin ProTxIIOur approach represents an unprecedented opportunity to develop therapeutic tools for the safe treatment of chronic pain and may have further applications to neuropathic and cancer pain