Hyperphosphatemia is universal to end stage chronic kidney disease patients and a majority of dialysis patients totaling of 400,000 in the US and 2 million worldwide. Current oral phosphate binders to treat hyperphosphatemia still have many drawbacks, including a high risk of calcification, high costs ($2100-$6500 per patient a year), low-to-moderate efficacy, gastrointestinal adverse effects, and high pill burdens (500-800 mg tablet, 3-12 tablets a day). These lead to low pill compliance, a major reason why patients fail to manage their hyperphosphatemia, which can be fatal. To address the medical need, PDX Pharmaceuticals, LLC is applying for an STTR Phase I grant for the development of a novel oral phosphate binder. Although this class of drugs generates ~ 1.4 billion USD a year in 2009 revenues, new R&D in search for the better drugs is lacking, lagging behind the state of technology. Innovation in this project lies in the utilization of our nanotechnology and ligand design expertise to revolutionize oral phosphate binders. Our goal is to develop a next generation drug with reduced costs, increased patients'compliance (by lowering pill burden and gastrointestinal side effects), and reduced drug associated risks. This Phase I project will involve bench-scale formulating of our iron functionalized silica (Fe-SAMMS), followed by efficacy and safety evaluations both in vitro and in rodent models against the standard of care drugs. Our preliminary studies show that Fe-SAMMS has a phosphate binding ability that is not dependent on pH or other competing anions relevant to gastrointestinal tract, is composed of benign chemicals including silica, iron, and, ethylenediamine- polysiloxane, and is virtually not soluble or absorbed to the body when tested in renal failure rats. SAMMS is readily scaled up within an existing manufacturing base, has a long shelf-life of over 8 years, and low production costs. This project will be a collaborative work between PDX Pharmaceuticals (an OHSU spin-off company) for material development and optimization, and OHSU for in vivo efficacy and safety evaluations by exploiting state of the art animal facilities and clinical expertise at OHSU. Results will lay a foundation for Phase II, intended for large-scale GMP production of the Fe-SAMMS, and its GLP safety evaluation toward the IND filing. Our strong team consists of the innovator and developer of SAMMS for metal capture in humans (Yantasee);an Associate Professor of OHSU (Gruber, MD), who has a long track record of drug evaluations in animals and moving drugs through the FDA processes;the former Chair of the Nephrology of the American Board of Internal Medicine (Anderson, MD);and a partner at Battelle Ventures (Warren), who specializes in commercialization of health &life science technologies coming out of Battelle's operated National Laboratories. We enjoy strong support from Battelle-PNNL and OHSU who co-own the IP right to be licensed to us, and the Oregon Nanoscience and Microtechnologies Institute (ONAMI), who is about to grant us initial gap funding for commercialization of this technology. Therefore, we fully anticipate a high chance of success for this project.

Public Health Relevance

We propose to develop a novel calcium-free oral phosphate binder to treat hyperphosphatemia in end stage chronic kidney disease patients. The new drug is aimed to have higher efficacy, less pill burden, lower costs, and less adverse effects, resultin in higher pill adherence than the current drugs.

National Institute of Health (NIH)
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Small Business Technology Transfer (STTR) Grants - Phase I (R41)
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Special Emphasis Panel (ZRG1-DKUS-L (11))
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Moxey-Mims, Marva M
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Pdx Pharmaceuticals, LLC
Lake Oswego
United States
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Sangvanich, Thanapon; Morry, Jingga; Fox, Cade et al. (2014) Novel oral detoxification of mercury, cadmium, and lead with thiol-modified nanoporous silica. ACS Appl Mater Interfaces 6:5483-93