XDx is a molecular diagnostics company with a focus on discovery, development, and commercialization of noninvasive gene expression testing that would translate a patient’s immune system information to clinically actionable information. The goal is to help in effective monitoring of transplant rejection and autoimmune diseases.
After the transplant, the organ recipient’s immune system recognizes a transplanted organ as foreign, and mounts a response to reject it. Currently, the only standard method to monitor for such rejection is endomyocardial biopsy and then prescribing drugs to suppress the body’s natural immune system response. There are two significant challenges. Endomyocardial biopsy is an invasive procedure that requires puncturing the jugular vein and inserting the guide with fluoroscopic or echocardiographic guidance. The jaws are then opened and a tiny piece of the heart is removed. This invasive procedure is performed weekly during the first month, with gradually reducing frequency to annually after twelve months. Besides being painful and an invasive procedure with potential of many complications, this is also an expensive procedure costing up to $4 to $10 thousand per biopsy. An additional challenge pertains to the determination of the dosage of immunosuppressant drugs. The correct dosage is determined on the basis of the information derived from the biopsies and this is somewhat of a subjective decision, with high consequences. The dose cannot be too high or too low as these drugs are powerful drugs with serious side effects, and frequently lead to renal or liver failure, in the long term.
AlloMap is XDx flagship product to aid in the identification of the probability of acute cellular rejection for post cardiac transplant patient management. This is a noninvasive method to monitor immune system activity by measuring gene expressing in a patient’s peripheral blood. The AlloMap blood test is CLIA certified and reports a score and is therefore a quantitative measure, that takes out the subjectivity from determining the right dose. The hope is also that the patient can then take the lowest possible dose needed. XDx has 30-44 thousand test capacity, annually. Not only is this a highly cost saving method to determine the right dosage, but it is a non-invasive, more humane method that should replace traditional biopsies.
Cassigneul shared results from several studies that indicate AlloMap to be as clinically effective as biopsies. And yet, the company has encountered revenue challenges, payer resisting coverage, hospitals making it more challenging to get the blood drawn and so on. However, recently Society of Heart Lung Transplant, recommended AlloMap in their clinical guidelines. This was a huge milestone for XDx and cleared the path for revenue generation. Now several payers have also recommended AlloMap for coverage. One hundred out of 140 transplant centers in theUS, have used the test and the company is seeing a steady growth. The company is working on several tests for monitoring of other transplant organs and also for monitoring several autoimmune diseases like Lupus, Rheumatoid Arthritis and so on. For Lupus, XDx is working on flare predictor so that sudden flare-ups can be caught prior to irreversible damage to kidneys and other organs. The talk generated strong interest and was followed by Q&A.