Pyridoxamine

Pyridoxamine can form fairly weak complexes with a number of transition metal ions, with a preference for Cu2+ and Fe3+. The 3'-hydroxyl group of pyridoxamine allows for efficient hydroxyl radical scavenging. which are associated with medical complications of diabetes. Pyridoxamine is hypothesized to trap intermediates in the formation of Amadori products released from glycated proteins, possibly preventing the breakdown of glycated proteins by disrupting the catalysis of this process through disruptive interactions with the metal ions crucial to the redox reaction. Pyridoxamine also inhibits the formation of advanced lipoxidation endproducts during lipid peroxidation reactions by reaction with dicarbonyl intermediates. In other preclinical research, pyridoxamine may be efficacious in treating diabetic neuropathy and retinopathy associated with diabetes ==FDA Regulatory Activity==

Pyridoxamine was marketed as a dietary supplement, often as the hydrochloride salt, pyridoxamine dihydrochloride. However, in the United States, the FDA ruled in January 2009 that pyridoxamine must be regulated as a pharmaceutical drug because it is the active ingredient in Pyridorin, a drug designed by Biostratum, Inc., to prevent the progression of diabetic nephropathy. Pyridorin had success in early clinical trials, found to be effective in slowing the progression of diabetic neuropathy in a phase II trial on 224 patients. In 2006, Biostratum licensed its rights in Pyridorin to another company, NephroGenex In 2008, NephroGenex restarted the clinical development of Pyridorin, which as of 2012 is still ongoing. NephroGenex conducted and completed a Phase 2b study and initiated a Phase 3 study of Pyridorin as treatment for diabetic neuropathy in patients with Type 2 diabetes. In February 24, 2016 NephroGenex was forced to pause the Phase 3 trial and ultimately terminate it later that year due to a lack of funding. The company subsequently filed for Chapter 11 bankruptcy on April 30, 2016. NephroGenex shortly thereafter sought out a corporate partner for licensing or acquisition of Pyridorin. The company retained the services of an investment banking firm which reached out to many prospective buyers, which by September 2016 had failed to consummate a transaction. NephroGenex then decided to sell all its assets, including Pyridorin, through a bankruptcy auction that was to be held on November 14, but was forced to cancel the auction after it did not receive any qualifying bids. On December 16, 2016, the company filed a motion with the bankruptcy court, proposing a liquidation plan. On August 24, 2017, the company's Investigational New Drug (IND) Applications with the FDA were withdrawn. Medpace, the Clinical Research Organization that conducted the Pyridorin Phase 3 trial, proposed and received approval for a Planned Support Agreement which transferred ownership of NephroGenex to Medpace. The new NephroGenex, renamed Medpace Research Inc., partnered with OxiPath Health Inc. to form a new venture, ViGuard Health Inc., with the intention of marketing the oral formulation of pyridoxamine as a dietary supplement, to which end it submitted, on October 3, 2017 a citizen petition to the FDA requesting the Commissioner issue a regulation stating pyridoxamine is a dietary supplement as defined by the Dietary Supplement Health and Education Act of 1994 DSHEA). ==See also==