Acer Therapeutics Inc. (‘Acer') and its collaboration partner, RELIEF THERAPEUTICS Holding SA (‘Relief') announced that the U.S. Patent and Trademark Office (USPTO) has issued a new U.S. patent to Acer for certain claims related to ACER-001 (sodium phenylbutyrate). Patent covers pharmaceutical composition claims related to ACER-001's taste-masked, multi-particulate dosage formulation for oral administration. The newly issued patent has an expiration date in 2036.

ACER-001 is an investigational product candidate which has not been approved by FDA, the European Medicines Agency (EMA), or any other regulatory authority. There can be no assurance that this product candidate will receive regulatory authority approval for marketing in any territory or become commercially available for the indications under investigation. UCDs are a group of disorders caused by genetic mutations that result in a deficiency in one of the six enzymes that catalyze the urea cycle, which can lead to an excess accumulation of ammonia in the bloodstream, a condition known as hyperammonemia.

Acute hyperammonemia can cause lethargy, somnolence, coma, and multi-organ failure, while chronic hyperammonemia can lead to headaches, confusion, lethargy, failure to thrive, behavioral changes, and learning and cognitive deficits. Common symptoms of both acute and chronic hyperammonemia also include seizures and psychiatric symptoms. The current treatment of patients with UCDs consists of dietary management to limit ammonia production in conjunction with medications that provide alternative pathways for the removal of ammonia from the bloodstream. Some patients may also require individual branched-chain amino acid supplementation.

Current medical treatments for patients with UCDs include nitrogen scavengers, RAVICTI® and BUPHENYL®, in which the active pharmaceutical ingredients are glycerol phenylbutyrate and sodium phenylbutyrate, respectively. According to a 2016 study by Shchelochkov et al., published in Molecular Genetics and Metabolism Reports, while nitrogen scavenging medications have been shown to be effective in helping to manage ammonia levels in some patients with UCDs, non-compliance with treatment is common. Reasons referenced for non-compliance associated with some available medications include unpleasant taste, frequency with which medication must be taken, required number of pills, and the high cost of the medication.

ACER-001 (sodium phenylbutyrate) is being developed for the treatment of various inborn errors of metabolism, including UCDs and MSUD. ACER-001 is a nitrogen-binding agent in development for use as adjunctive therapy in the chronic management of patients with UCDs involving deficiencies of carbamylphosphate synthetase (CPS), ornithine transcarbamylase (OTC), or argininosuccinic acid synthetase (AS). The formulation is a multi-particulate dosage formulation for oral administration consisting of a core center, a layer of active drug, and a taste-masked coating designed to avoid the bitter taste of sodium phenylbutyrate in the mouth while quickly dissolving in the low pH of the stomach.

The ACER-001 NDA for UCDs is currently under FDA review with a PDUFA target action date of June 5, 2022. ACER-001 is also being developed for MSUD and has been granted orphan drug designation by the FDA for this indication. ACER-001 is an investigational product candidate which has not been approved by FDA, the European Medicines Agency (EMA), or any other regulatory authority.