Acer Therapeutics Inc. and its collaboration partner, Relief Therapeutics Holding SA announced the presentation of data evaluating the bioavailability, bioequivalence and taste attributes of ACER-001 (sodium phenylbutyrate) compared to sodium phenylbutyrate (BUPHENYL) powder during poster sessions at the recent Genetic Metabolic Dieticians International (GMDI) Conference on May 5, 2022, in Las Vegas, Nevada. ACER-001: A Potential Alternative to Sodium and Glycerol Phenylbutyrate for Treatment of Urea Cycle Disorders: This poster summarizes results from two Phase 1 bridging studies that evaluated the bioavailability and bioequivalence of ACER-001 (sodium phenylbutyrate) compared to sodium phenylbutyrate (BUPHENYL) powder. The objectives of the two studies were to determine the bioequivalence of ACER-001 administered as a suspension relative to sodium phenylbutyrate (BUPHENYL) powder administered as a solution in healthy adult volunteers after a single dose under fasting and fed conditions, and to assess the effect of a high-fat meal on the pharmacokinetics (PK) of ACER-001.

The data presented concluded that ACER-001 was bioequivalent to sodium phenylbutyrate (BUPHENYL) powder under both fed and fasting conditions. Higher levels of phenylbutyrate (PBA) and phenylacetate (PAA), a conjugate base of phenylacetic acid, were observed when ACER-001 was administered under fasting versus fed conditions. A similar reduction in the PK of sodium phenylbutyrate (BUPHENYL) powder under fed conditions was observed between the fasted and fed studies.

Adverse events in these studies showed no major safety signals and were similar to sodium phenylbutyrate (BUPHENYL). These studies suggest investigating administration of nitrogen scavengers under fasting conditions, which may ultimately provide lower dose options and increase dosing flexibility. Taste-Masked Coating of Sodium Phenylbutyrate (ACER-001) Improves the Palatability of Sodium Phenylbutyrate for Treatment of Urea Cycle Disorders: The second poster presented at GMDI details results from two Phase 1, open-label, repeated measures, taste assessment studies of polymer coated sodium phenylbutyrate (ACER-001) and sodium phenylbutyrate (BUPHENYL) powder.

The studies included healthy panelists who were required to complete a training program for a minimum of six months that educated panelists on the identification, description, and quantification of sensory attributes of products. The objective of the two taste assessment studies was to identify and quantify the intensity of perceived flavor attributes of ACER-001 relative to sodium phenylbutyrate (BUPHENYL) powder. Results from both studies concluded that ACER-001 was shown to have overall lower flavor intensity scores than sodium phenylbutyrate (BUPHENYL) powder when administered within five minutes of preparation.