• Acer Therapeutics reports data from a survey of UCD healthcare providers show taste and odor are the most important attributes when considering treatment options and adherence

GENEVA, SWITZERLAND / ACCESSWIRE / March 22, 2023 / RELIEF THERAPEUTICS Holding SA (SIX:RLF) (OTCQB:RLFTF) (OTCQB:RLFTY) ("Relief Therapeutics"), a biopharmaceutical company committed to advancing treatment paradigms and delivering improvements in efficacy, safety and convenience to benefit the lives of patients living with rare diseases, today announces survey results identifying preferred urea cycle disorder (UCD) treatment attributes from its collaboration partner ACER Therapeutics, Inc. ("Acer" or the "Company"). The survey results were presented by Professor Robert Steiner, M.D. at the 44 ^th Annual Meeting of the Society for Inherited Metabolic Disorders (SIMD) on Sunday, March 19 in Salt Lake City.

Designed to quantify preferences of healthcare providers who treat patients with UCDs, the survey results show that taste and odor are the most important attributes influencing 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 said Robert Steiner, M.D., professor at the University of Wisconsin School of Medicine and Public Health. "However, 25 percent 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 adherence. ³ Given these results, alternative treatment options are urgently needed."

Poster #97: Quantifying Preferences for Urea Cycle Disorder Treatments Using a Discrete-Choice Experiment ⁴

This poster summarizes results from a web-based, quantitative survey conducted on Acer's behalf using a discrete choice experiment (DCE) methodology and is now available on the Acer Therapeutics website. The goal of the survey was 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 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 show that taste and odor are the most important attributes for both prescribing and 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 the treatment of patients with UCDs.

"The results from this healthcare provider UCD treatment preferences survey are encouraging for the potential market uptake of OLPRUVA™, which is anticipated to launch in Q2 2023," said Jack Weinstein, chief executive officer at Relief Therapeutics. "OLPRUVA™ leverages the well-established efficacy of sodium phenylbutyrate in an innovative dual-coating formulation designed for palatability ⁵ and will be available in single-dose envelopes, which may help people living with UCD manage their condition."

Previously Presented ACER-001 (sodium phenylbutyrate) Palatability Data

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 previously presented at the 43 ^rd SIMD Annual Meeting in April 2022 and the Genetic Metabolic Dieticians International (GMDI) Conference in May 2022. Results from both studies concluded that ACER-001 (sodium phenylbutyrate) suspension had overall lower flavor intensity scores than sodium phenylbutyrate (BUPHENYL ^® ) powder when administered within five minutes of preparation. In December 2022, the U.S. Food and Drug Administration (FDA) approved ACER-001 (sodium phenylbutyrate) for oral suspension for the treatment of patients living with certain UCDs and is now marketed in the U.S. under the brand name OLPRUVA™.

ABOUT UREA CYCLE DISORDERS

Urea cycle disorders (UCDs) are a group of rare, genetic disorders that can cause harmful ammonia to build up in the blood. Any increase in ammonia over time is serious. Long-term toxic ammonia levels can lead to liver and brain damage, severe ketoacidosis, and can even be fatal when left untreated. ⁸ Therefore, it is important to adhere to any dietary protein restrictions and have alternative medication options to help control ammonia levels. Non-compliance with current therapies is a major issue due to unpleasant taste and odor and cost of treatment.

ABOUT OLPRUVA™ (SODIUM PHENYLBUTYRATE, ACER-001) FOR ORAL SUSPENSION

In March 2021, Relief signed a collaboration and license agreement with Acer for the worldwide development and commercialization of ACER-001. On Dec. 22, 2022, the U.S. Food and Drug Administration (FDA) approved OLPRUVA™ (sodium phenylbutyrate, ACER-001) for oral suspension as a prescription medicine for use 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). ⁵ Please see Important Safety Information and full Prescribing Information , including Patient Information .

ABOUT RELIEF THERAPEUTICS

Relief Therapeutics is a commercial-stage biopharmaceutical company committed to advancing treatment paradigms and delivering improvements in efficacy, safety and convenience to benefit the lives of patients living with rare diseases. Since founding in 2013, Relief Therapeutics continues to build a diversified pipeline of risk-mitigated assets to address metabolic, dermatology/connective tissue disorders as well as pulmonary and genetic diseases. Our portfolio also includes a balanced mix of marketed, revenue-generating products and the proprietary, globally patented Physiomimic™ and Tehclo ^® platform technologies which were obtained through the acquisition of APR Applied Pharma Research SA in June 2021. Our mission is being advanced by an international team of well-established, experienced biopharma industry leaders with extensive research, development and rare disease expertise. Relief Therapeutics' headquarters are located in Geneva, with additional offices in Balerna, Switzerland, Rome, Italy and Offenbach am Main, Germany. The Company is listed on the SIX Swiss Exchange under the symbol RLF and quoted in the U.S. on OTCQB under the symbols RLFTF and RLFTY. For more information, please visit www.relieftherapeutics.com or follow Relief Therapeutics on LinkedIn and Twitter .

DISCLAIMER

This communication expressly or implicitly contains certain forward-looking statements concerning RELIEF THERAPEUTICS Holding SA and its businesses. Such statements involve certain known and unknown risks, uncertainties and other factors, including those risks described in RELIEF THERAPEUTICS Holding SA's press releases and filings with the SIX Swiss Exchange and the U.S. Securities and Exchange Commission, all of which could cause the actual results, financial condition, performance or achievements of RELIEF THERAPEUTICS Holding SA to be materially different from any future results, performance or achievements expressed or implied by such forward-looking statements. RELIEF THERAPEUTICS Holding SA is providing this communication as of this date and does not undertake to update any forward-looking statements contained herein as a result of new information, future events or otherwise.

REFERENCES

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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.
8. Ah Mew N, et al. Urea cycle disorders overview [updated June 22, 2017]. In: Adam MP, Ardinger HH, Pagon RA, et al, eds. GeneReviews ^® [Internet]. University of Washington; 1993-2022. Accessed March 20, 2022.