Acer Therapeutics Develops the First Pharmaceutical Therapy for Maple Syrup Urine Disease (MSUD)
Maple syrup urine disease (MSUD) is a rare genetic disorder, with a reported worldwide incidence of one in 185,000. It is estimated that there may be 3,400 to 4,100 patients in the world and 800 to 1,000 patients in the United States alone.
MSUD is caused by defects in branched-chain α-keto acid dehydrogenase complex (BCKDC). The defect impairs the BCKDC’s function to break down branched chain amino acids (BCAAs) and their respective branched-chain a-ketoacids (BCKAs), causing abnormal accumulation of BCAAs and BCKAs in the patient. If left untreated, excessively high levels of these amino acids and their corresponding keto acids can lead to neurological damages, coma, or even death. Current therapy for MSUD is limited to dietary restriction of BCAA intake or liver transplantation, which is not always successful. There currently is no available pharmacological treatment for this disease.
Dr. Brendan Lee and his team at Baylor College of Medicine found that in patients with urea cycle disorders phenylbutyrate (NaPBA), therapy results in a selective reduction in BCAA in the absence of dietary restriction. Based on this observation, Dr. Lee has investigated the effect of phenylbutyrate on plasma BCAA and BCKA in a pilot clinical study and found that both are significantly reduced in control subjects and in patients with a late-onset form of MSUD. These research achievements by Dr. Lee set the foundation for utilizing NaPBA or its derivatives to treat MSUD. A Phase II/ III placebo-controlled clinical trial with the aim to further validate the efficacy of NaPBA was initiated by Baylor College of Medicine and is currently recruiting patients.
Acer Therapeutics Inc. entered into an exclusive license agreement with Baylor College of Medicine to commercialize the promising MSUD treatment. The business model of Acer Therapeutics is to repurpose and reformulate existing therapeutics for orphan indications with unmet medical needs. The company is led by an experienced team of biopharma veterans, Chris Schelling, Jefferson Davis, and Harry Palmin, who possess valuable expertise and a brilliant track record for development and commercialization of orphan drugs. Acer Therapeutics conducted additional proof-of-concept studies in consultation with Dr. Lee, and gained further insights into the therapeutic mechanisms of NaPBA.
Supported by solid research data, Acer Therapeutics recently was granted the Orphan Designation Status by the FDA for using NaPBA in treatment of MSUD, which means the company is qualified for various development incentives under the Orphan Drug Act. Acer Therapeutics is in the process of raising capital and expects to initiate a randomized, controlled, double-blind Phase III clinical study of NaPBA in 2015.