Tethered Enzyme Technology for PoC and At-home Real-time Monitoring of Liver Function

Abstract TETmedical Inc. is developing a tethered enzyme technology (TET) for rapid point-of-care (PoC) and/or at-home testing of liver enzyme levels, enabling convenient and timely tracking of drug-induced liver injury (DILI) and other sources of liver damage. When the liver is damaged or diseased, the enzymes aspartate aminotransferase (AST) and alanine aminotransferase (ALT) are released into the blood, making these the most frequently used markers of hepatocellular injury. Because the liver is the primary site of drug metabolism, patients’ AST and ALT levels are often evaluated to monitor DILI as a key component of clinical trials to determine drug safety. Currently, to have the test performed, patients must travel to a clinic to have a blood sample drawn, which is then tested in an in-house laboratory or mailed off to a central laboratory testing facility. Visits to the clinic place a burden on the elderly and/or those with limited mobility, and add a geographic constraint to clinical trial participants, reducing the diversity of subjects. The testing process is slow, burdensome, and costly, and severely limits the frequency of testing and the speed with which a problem can be detected. In response to this need, TETmedical is advancing a simple, rapid, and affordable test for AST/ALT measurement that can be performed at the PoC or in the patient’s own home based on a biomimetic approach to oriented immobilization of enzymes on nanoparticles (NPs). This method significantly improves the efficiency of coupled enzymatic reactions and is based on the TET platform that enables ultra-rapid, highly sensitive, and quantitative detection of analytes. Of note, TETmedical has enabled luminescence readouts of AST/ALT in the highly reducing environment of human serum/plasma, thus overcoming a challenge that prevented luminescent quantification of AST/ALT. TETmedical’s AST/ALT test will include disposable cartridges with the TET biosensor embedded on a paper- based blood separator and, due to a recent partnership, a lancet based blood sample collection device to enable repeated at-home testing of liver enzymes. Once the sample is added to the cartridge, it will then be inserted into an electronic reader that will measure the luminescence-based readout and provide a quantitative result. For this Phase I project, TETmedical’s Specific Aims are: 1) Optimize the tethered enzyme assays for detection of AST and ALT including the speed, range of detection, and calibration of luminescence outputs, 2) Improve separation of blood components and design of cartridges, and 3) Validate technology using spiked human blood samples. Completion of these Aims will result in a cartridge integrating blood separation and TET biosensors to quantify AST and ALT, and controls for hemolysis, which are already under development. This will provide the necessary proof of concept for a future Phase II application, which will include a validation study in clinical samples, integration with the at-home blood collection device, and further development of the prototype electronic reader device, enabling simple PoC or at-home use.