Acer Therapeutics Announces Data Presented at Society for Inherited Metabolic Disorders Annual Meeting Identifying Preferred Urea Cycle Disorder Treatment Attributes

Results from survey of Urea Cycle Disorders (UCD) healthcare providers show taste and odor were the most important attributes when considering treatment options and treatment adherence

NEWTON, Mass., March 22, 2023 (GLOBE NEWSWIRE) — Acer Therapeutics Inc. (Nasdaq: ACER), a pharmaceutical company focused on the acquisition, development and commercialization of therapies for serious, rare and life-threatening diseases with significant unmet medical needs, today announced data was presented from a survey designed to quantify preferences of healthcare providers for Urea Cycle Disorders (UCDs) at the 44^th Annual Meeting of the Society for Inherited Metabolic Disorders (SIMD), March 18^th-21^st in Salt Lake City, Utah. Results from the discrete choice experiment presented showed that taste and odor were the most important attributes, as identified by UCD healthcare providers, that influence overall prescription of, and patient adherence to, UCD treatments when evaluating nitrogen-binding medications (such as sodium phenylbutyrate and glycerol phenylbutyrate).

“Nitrogen-binding medications, such as sodium phenylbutyrate or glycerol phenylbutyrate, can be efficacious in the treatment of UCDs if patients are adherent to their prescribed treatment^1,2,” stated Robert Steiner, M.D., Professor at the University of Wisconsin School of Medicine and Public Health. “However, 25% of life-threatening hyperammonemic crises in patients with UCDs may be precipitated by a lack of adherence to medications and/or diet and certain attributes of existing nitrogen-binding medications may negatively impact adherence³. Given these results, alternative treatment options are urgently needed.”

Healthcare Provider UCD Treatment Preference Data Presented at SIMD 2023
A copy of the poster presentation from the 2023 SIMD Meeting is available on Acer’s website at: https://www.acertx.com/wp-content/uploads/2023/03/2023-SIMD-DCE-Poster.pdf

Poster #97: Quantifying Preferences for Urea Cycle Disorder Treatments Using a Discrete-Choice Experiment⁴
This poster presented at SIMD summarizes results from a web-based, quantitative survey study conducted on Acer’s behalf, using a discrete choice experiment (DCE) methodology. This study was designed to quantify the most-desired product attributes that may influence overall prescription of, and patient adherence to, nitrogen-binding medications (such as sodium phenylbutyrate and glycerol phenylbutyrate) for the treatment of UCDs as identified by the survey participants.

Of the 51 healthcare providers that completed the survey, most HCPs reported dissatisfaction with current treatment options [mean rating (SD)=5.4 (1.7); Likert scale with 1 = not at all satisfied through 9 = extremely satisfied]. The results of the survey showed that taste and odor were the most important attributes for both prescribing and for patient adherence and compliance . The authors concluded that optimizing nitrogen-binding medications for UCD treatment to facilitate and encourage increased patient adherence through masking taste and odor, and/or enhancing other aspects of the patient experience, may support improved outcomes in UCDs.

“OLPRUVA™⁵ leverages the well-established efficacy of sodium phenylbutyrate in an innovative dual-coating formulation designed for palatability,” said Adrian Quartel, MD, FFPM, CMO of Acer. “We are pleased to offer an innovative, responsibly priced treatment option to patients with UCDs and remain committed to working closely with the UCD community to ensure that those affected by this terrible disease live their lives with as few challenges and interruptions as possible.”

ACER-001 (sodium phenylbutyrate) Palatability Data Presented at SIMD and GMDI 2022
Taste-Masked Coating of Sodium Phenylbutyrate (ACER-001) Improves the Palatability of Sodium Phenylbutyrate for Treatment of Urea Cycle Disorders^6,7
Results from two Phase 1, open-label, repeated measures, taste assessment studies of ACER-001 (sodium phenylbutyrate) suspension and sodium phenylbutyrate (BUPHENYL^®) powder were presented at the SIMD Annual Meeting and Genetic Metabolic Dieticians International (GMDI) Conference in April 2022 and May 2022, respectively. ACER-001 for the treatment of certain UCDs is now marketed in the U.S. as OLPRUVA™ (sodium phenylbutyrate) following FDA approval in December 2022. Results from both studies concluded that ACER-001 (sodium phenylbutyrate) suspension was shown to have overall lower flavor intensity scores than sodium phenylbutyrate (BUPHENYL^®) powder when administered within five minutes of preparation.

New FDA-Approved UCD Treatment Option: OLPRUVA™
ACER-001 (sodium phenylbutyrate) was approved for the treatment of certain UCDs in December 2022 and is marketed under the brand name, OLPRUVA™. OLPRUVA™ (sodium phenylbutyrate) for oral suspension is a prescription medicine used along with certain therapy, including changes in diet, for the long-term management of adults and children weighing 44 pounds (20 kg) or greater and with a body surface area (BSA) of 1.2 m2 or greater, with urea cycle disorders (UCDs), involving deficiencies of carbamylphosphate synthetase (CPS), ornithine transcarbamylase (OTC), or argininosuccinic acid synthetase (AS).⁴ Please see Important Safety Information and full Prescribing Information, including Patient Information.

About Acer Therapeutics
Acer is a pharmaceutical company focused on the acquisition, development and commercialization of therapies for serious rare and life-threatening diseases with significant unmet medical needs. In the U.S., OLPRUVA™ (sodium phenylbutyrate) is approved for the treatment of urea cycle disorders (UCDs) involving deficiencies of carbamylphosphate synthetase (CPS), ornithine transcarbamylase (OTC), or argininosuccinic acid synthetase (AS). Acer is also advancing a pipeline of investigational product candidates for rare and life-threatening diseases, including: OLPRUVA™ (sodium phenylbutyrate) for treatment of various disorders, including Maple Syrup Urine Disease (MSUD); EDSIVO™ (celiprolol) for treatment of vascular Ehlers-Danlos syndrome (vEDS) in patients with a confirmed type III collagen (COL3A1) mutation; and ACER-801 (osanetant) for treatment of Vasomotor Symptoms (VMS), post-traumatic stress disorder (PTSD) and prostate cancer. For more information, visit www.acertx.com.

References

1. Batshaw ML, Tuchman M, Summar M, Seminara J, Members of the Urea Cycle Disorders C. A longitudinal study of urea cycle disorders. Mol Genet Metab. 2014;113(1-2):127-130.
2. Pena-Quintana L, Llarena M, Reyes-Suarez D, Aldamiz-Echevarria L. Profile of sodium phenylbutyrate granules for the treatment of urea-cycle disorders: patient perspectives. Patient Prefer Adherence. 2017;11:1489-1496.
3. Pena-Quintana L, Llarena M, Reyes-Suarez D, Aldamiz-Echevarria L. Profile of sodium phenylbutyrate granules for the treatment of urea-cycle disorders: patient perspectives. Patient Prefer Adherence. 2017;11:1489-1496.
4. Edelblut J, et al. Quantifying Preferences for Urea Cycle Disorder Treatments Using a Discrete-Choice Experiment. SIMD March 2023
5. OLPRUVA^TM (sodium phenylbutyrate) for oral suspension. Prescribing information. Newton, MA: Acer Therapeutics Inc.
6. Steiner R, et al. The Pharmacokinetics of Taste-Masked Sodium Phenylbutyrate (ACER-001) for the Treatment of Urea Cycle Disorders Under Fasting and Fed Conditions in Healthy Volunteers. SIMD April 2022
7. Cederbaum S, et al. Taste-Masked Coating of Sodium Phenylbutyrate (ACER-001) Improves the Palatability of Sodium Phenylbutyrate for Treatment of Urea Cycle Disorders. GMDI May 2022

Acer Forward-Looking Statements
This press release contains “forward-looking statements” that involve substantial risks and uncertainties for purposes of the safe harbor provided by the Private Securities Litigation Reform Act of 1995. All statements, other than statements of historical facts, included in this press release are forward-looking statements. Examples of such statements include, but are not limited to, statements about survey data to be presented, including the timing, detail and content thereof, and OLPRUVA™ launch activities, including the addition of resources, the launch of patient support services, discussions with payers and organizations, and the Company’s pricing strategy and related plans and expectations. Our efforts to commercialize OLPRUVA™ for oral suspension in the U.S. for the treatment of certain patients with UCDs involving deficiencies of CPS, OTC, or AS are at an early stage, we currently do not have fully developed marketing, sales or distribution capabilities, and there is no guarantee that we will be successful in our commercialization efforts. Our pipeline products (including OLPRUVA™ for indications other than UCDs) are under investigation and their safety and efficacy have not been established and there is no guarantee that any of our investigational products in development will receive health authority approval or become commercially available for the uses being investigated. We may not actually achieve the plans, carry out the intentions or meet the expectations or projections disclosed in the forward-looking statements and you should not place undue reliance on these forward-looking statements. Such statements are based on management’s current expectations and involve risks and uncertainties. Actual results and performance could differ materially from those projected in the forward-looking statements as a result of many factors, including, without limitation, the availability of financing to fund our commercialization efforts, our pipeline product development programs and general corporate operations as well as risks related to drug development and the regulatory approval process, including the timing and requirements of regulatory actions. We disclaim any intent or obligation to update these forward-looking statements to reflect events or circumstances that exist after the date on which they were made. You should review additional disclosures we make in our filings with the Securities and Exchange Commission, including our Annual Report on Form 10-K and Quarterly Reports on Form 10-Q. You may access these documents for no charge at http://www.sec.gov.

Corporate and IR Contacts
Jim DeNike
Acer Therapeutics Inc.
jdenike@acertx.com
+1-844-902-6100

Nick Colangelo
Gilmartin Group
nick@gilmartinIR.com
+1-332-895-3226