Development of an Enhanced, Simplified Blood Coagulation Test to Monitor Patients on Direct Oral Anti-Coagulants

Project SummaryOver the lastyearsDirect Oral AnticoagulantsDOACshave become increasingly prevalent for treating patients with cardiovascular disorders because of their pharmacokinetic stability and lack of interaction with certain foodsYetthere is increasing evidence of improper dosing in a small proportion of treated patientsand growing recognition of the need to develop simpleinexpensive tests to measure DOAC effects for acute blood loss trauma or embolic eventsThere is currently no single assay which fulfills these needs and provides the requisite levels of accuracy and sensitivity to quantify all DOACsThis application presents preliminary data from a modified dilute PT assay which displays highly sensitive clotting time responses to DabigatranRivaroxabanand Apixabanwhich we have named theExtrinsic Pathway Clot TimeEPCTAssayThe key components of the EPCT are re lipidated tissue factorTFtriggering agentE plastinand the specific Factor XIIa inhibitorcorn trypsin inhibitorCTIwhich blocks contact pathway activation in collected blood samplesallowing long artifact free clot timesThe goal of this proposal is to fine tune the EPCT Assay to provide a simple to executeuniversaltechnique which can be performed on standard laboratory coagulometersand allows timelysensitiveunambiguous measurements of the pharmacodynamic effects of DOACsIn Aima variety of E Plastin reagents with variations in phospholipid content and composition will be synthesized in house using recombinantexpressed rabbit TFand characterized in vitroAfter determination of the optimal dilution levels to give the DOAC free long clot times needed for optimal sensitivitydose response curves to DOAC spiked blood taken from a number of healthy subjects will then be acquired for the various E Plastin preparationsusing both mechanical detection of clotting in whole bloodand optical detection in plasmaResults for the direct FXa inhibitors will be compared with chromogenic assays which quantify mass levelWe will perform statistically weighted comparisons of the slope of the response for different subjects to different DOACS while addressing the following questionsHow much impact do the variations in E Plastin composition have on response sensitivitycurve slopeto a given DOAC within and between subjectsAre the sensitivities of response curves to different DOACs significantly different when using a single E Plastin for individual subjectsAre the dose response curve slopes to a specific DOAC significantly different between subjects when averaged over multiple times of assay performance for a given E PlastinIn Aimwe will collaborate with DrSchneider to use the EPCT assay for measurements on samples from patients suffering with various disordersespecially atrial fibrillationwho are being treated with DOACsanti platelet agentsand WarfarinThe goal of these studies will be to determine whether the EPCT assay can be used to enhance the ability of the clinician to spot patients at higher risk for bleeding or embolic eventsallowing them to correctly adjust dosing to decrease the prevalence of these adverse outcomes Project NarrativeIn the current SBIR applicationour company proposes to develop a test which could be used to evaluate the blood clotting status of patients who are being treated with a new generation ofblood thinningor antithromboticdrugscalled Direct Oral Anti CoagulantsDOACsThere is currently no single test which can be reliably used to assess the status of these patientsso we believe that our procedure could prove important to monitor these patientsparticularly when their circumstances changesuch as preor post surgeryor when they have an acute bleeding incident