Author: AcerUser

NEWTON, MA – May 15, 2023 – 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 reported financial results for the first quarter ended March 31, 2023 and provided a corporate update.

“The first quarter of 2023 was marked by considerable progress and a number of significant milestones in support of our commercial launch of OLPRUVA™, an innovative treatment option for patients with certain Urea Cycle Disorders (UCDs),” said Chris Schelling, CEO and Founder of Acer. “As a result, we are now ahead of our anticipated launch schedule with drug-in-channel expected in mid-June 2023. We have also made significant progress in the other key areas of our OLPRUVA™ commercialization strategy, including ongoing discussions with commercial and government insurance providers, physician outreach and awareness, and patient support and fulfillment. We look forward to continued progress in all of these areas and to delivering OLPRUVA™ to patients in mid-June 2023.”

Mr. Schelling added, “We have also started a broad outreach program to physicians who treat vascular Ehlers-Danlos Syndrome (vEDS) patients and have received overwhelming support for our ongoing Decentralized Study of Celiprolol on vEDS-related Event Reduction (DiSCOVER) Phase 3 EDSIVO™ (celiprolol) clinical trial. As a result, we anticipate enrollment in this trial to be completed by the end of this year. All of these activities are subject to additional capital.”

Q1 2023 and Recent Highlights

• OLPRUVA™ (sodium phenylbutyrate) for oral suspension
  • In March 2023, Acer announced the presentation of data at the Annual Meeting of the Society for Inherited Metabolic Disorders (SIMD) from a survey of UCD healthcare providers sponsored by Acer that indicated taste and odor were the most important attributes when considering treatment options and treatment adherence
  • Also at the SIMD Annual Meeting, Acer representatives met with 33 metabolic treatment providers — including nurse practitioners, registered dieticians, and physicians – from 24 metabolic treatment centers throughout the U.S. Of those metabolic treatment providers surveyed by Acer, 70% expressed a high interest in treating at least one of their patients with OLPRUVA™ in 2023
  • In preparation for OLPRUVA™’s planned drug-in-channel in mid-June 2023, the Company is in discussions with the major pharmacy benefits managers (PBM) and group purchasing organizations (GPO) representing a substantial majority of covered lives
  • Acer has also established a responsible and competitive pricing strategy designed to offer UCD patients a new treatment option at a significant discount to RAVICTI® while delivering predictable pricing that will not increase beyond the rate of inflation. Acer also plans to invest a portion of OLPRUVA™ revenue back into additional solutions aimed at improving outcomes for UCD patients
  • Finally, Acer has established and staffed its patient support program, Navigator by Acer Therapeutics, that includes a suite of services designed to provide streamlined and efficient prescription management — including benefits verification, education, and home delivery — and personalized support for OLPRUVA™ patients
• EDSIVO™ (celiprolol)
  • Acer continues to enroll patients in its ongoing, pivotal Phase 3 Decentralized Study of Celiprolol on vEDS-related Event Reduction (DiSCOVER) clinical trial of EDSIVO™ (celiprolol) in patients with COL3A1-positive vEDS. The double-blind portion of the DiSCOVER trial is designed to include an interim analysis conducted after 28 vEDS related events, which could occur as early as approximately 18 months after completion of full enrollment; and end if statistical significance is reached after 46 vEDS-related events, estimated to occur as early as approximately 40 months after completion of full enrollment
• ACER-801
  • In March 2023, Acer announced topline results from its Phase 2a trial evaluating ACER-801 (osanetant) for the treatment of moderate to severe Vasomotor Symptoms (VMS) associated with menopause. The trial showed that ACER-801 was generally safe and well-tolerated but did not achieve statistically significant decrease in frequency or severity of hot flashes in postmenopausal women. As a result, Acer has paused the ACER-801 program until it has completed a thorough review of the full data set from the Phase 2a trial
• Corporate
  • Ended Q1 2023 with $6.4 million in cash and cash equivalents. Acer believes its cash and cash equivalents available at March 31, 2023, together with $0.4 million from Acer’s ATM facility subsequent to March 31, 2023, will be sufficient to fund its anticipated operating and capital requirements into late in the second quarter of 2023

Anticipated Milestones (Subject to Available Capital)

• Mid-to-Late May 2023: Acer expects to publish OLPRUVA™’s list price, or wholesale acquisition cost (WAC), in mid-to-late May 2023
• June 2023: Acer anticipates OLPRUVA™ drug availability in mid-June 2023
• 2H 2023: Acer expects to begin attaining OLPRUVA™ commercial insurance coverage in 2H 2023
• Q3 2023: Acer expects to begin attaining insurance coverage for OLPRUVA™ Medicaid patients starting in Q3 2023
• Year End 2023: Acer anticipates enrollment completion by end of 2023 in its ongoing, pivotal Phase 3 DiSCOVER trial of EDSIVO™ in patients with COL3A1-positive vEDS
• Acer also intends to pursue additional opportunities for potential OLPRUVA™ label expansion, including the potential for additional dosage strengths to address patients with lower weights/body surface areas, and potential administration using a gastrostomy tube (G-tube)

Q1 2023 Financial Results

Cash Position. Cash and cash equivalents were $6.4 million as of March 31, 2023, compared to $2.3 million as of December 31, 2022. Acer believes its cash and cash equivalents available at March 31, 2023, together with $0.4 million from Acer’s ATM facility subsequent to March 31, 2023, will be sufficient to fund its anticipated operating and capital requirements into late in the second quarter of 2023.

Research and Development Expenses. Research and development expenses were $2.4 million, net of collaboration funding of $0.7 million, for the three months ended March 31, 2023, as compared to $3.2 million, net of collaboration funding of $3.0 million, for the three months ended March 31, 2022. This decrease of $0.8 million was primarily due to decreases in expenses for contract manufacturing and contract research, employee-related expenses, and clinical studies related to ACER-801 and EDSIVO^TM. Research and development expenses related to ACER-001 decreased in the three months ended March 31, 2023, resulting in a decrease in the recognition of the collaboration funding from the Collaboration Agreement with Relief. Research and development expenses for the three months ended March 31, 2023 were comprised of $1.0 million related to EDSIVO^TM; $0.8 million related to ACER-001, offset by $0.7 million of collaboration funding; $0.8 million related to ACER-801; and $0.5 million related to other development activities.

General and Administrative Expenses. General and administrative expenses were $2.6 million, net of collaboration funding of $1.1 million, for the three months ended March 31, 2023, as compared to $3.9 million, net of collaboration funding of $2.4 million, for the three months ended March 31, 2022. This decrease of $1.3 million was primarily due to decreases in employee-related expenses, precommercial expenses, and consulting fees. General and administrative expenses related to ACER-001 decreased in the three months ended March 31, 2023, resulting in a decrease in the recognition of the collaboration funding from the Collaboration Agreement with Relief.

Net Loss. Net loss for the three months ended March 31, 2023 was $16.3 million, or $0.77 net loss per share (basic and diluted), compared to a net loss of $9.2 million, or $0.64 net loss per share (basic and diluted), for the three months ended March 31, 2022.

For additional information, please see Acer’s Quarterly Report on Form 10-Q filed today with the Securities and Exchange Commission (SEC).

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; 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. 

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 plans and strategy for the commercialization of OLPRUVA™ for oral suspension in the U.S. for the treatment of certain patients with certain UCDs, including launch schedule and timing of drug in channel, progress with respect to discussions with commercial and government insurance providers, physicians outreach and awareness, and patient support and fulfillment, statements with respect to our EDSIVO clinical trial for patients with vEDS, including enrollment and timing milestones related thereto, statements about our anticipated 2023 milestones, statements about our investment of OLPRUVA revenue, and statements about our capital requirements and sufficiency and duration of our current cash and cash equivalents. 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 as well as EDSIVO™ and ACER-801) 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 our 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 Contact

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

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

NEWTON, MA – May 1, 2023 – 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 an update on progress in support of its commercial launch of OLPRUVA™ (sodium phenylbutyrate) for oral suspension, including drug availability now expected earlier than anticipated in mid-June 2023, subject to additional capital.

“Since the U.S. FDA approval of OLPRUVA™ at the end of 2022, we and our partners have been working diligently to bring this innovative treatment option to UCD patients in need as soon as possible,” said Chris Schelling, CEO and Founder of Acer. “As a result of these efforts, I am pleased to report we are ahead of our anticipated launch schedule and now expect drug availability beginning in mid-June 2023. We have also made significant progress in our ongoing discussions with payers regarding reimbursement, increased physician awareness and interest, and built out our patient support and fulfillment program. We look forward to continued progress across these and other launch initiatives and to delivering OLPRUVA™ to patients starting in mid-June 2023, subject to additional capital.”

Availability
As a result of the ongoing launch readiness efforts by Acer representatives and its manufacturing partners, Acer now expects select OLPRUVA™ dose levels to be available to patients beginning in mid-June 2023, at which time representatives from Acer’s patient support service will be available to begin accepting prescriptions. Acer expects to publish OLPRUVA™’s list price, or wholesale acquisition cost (WAC), in mid-to-late May.

Patient and Physician Awareness
Acer has also made significant progress in support of its objective to raise awareness for OLPRUVA™ as a new, alternative treatment option for certain UCD patients. Most recently, the Company attended and exhibited at the 44th Annual Meeting of the Society for Inherited Metabolic Disorders (SIMD), in March 2023.

During the annual meeting, the Company met with 33 metabolic treatment providers — including nurse practitioners, registered dieticians, and physicians – from 24 metabolic treatment centers throughout the U.S. Of those metabolic treatment providers surveyed by Acer, 70% expressed a high interest in treating at least one of their patients with OLPRUVA™ in 2023. Providers surveyed also stated they viewed OLPRUVA™ as an attractive alternative therapy for UCD patients citing that despite available nitrogen scavengers in the market today, there are still unmet needs for UCD patients that may likely be addressed by prescribing OLPRUVA™.

Reimbursement
Acer Therapeutics has been engaged with both commercial and government payers as the Company anticipates approximately 50% of OLPRUVA™ prescriptions to be reimbursed through Medicaid, 45% through commercial payers, and 5% Medicare Part D. The Company is in discussions with the major pharmacy benefits managers (PBM) and group purchasing organizations (GPO) representing a substantial majority of covered lives, and Acer believes it will begin attaining OLPRUVA™ commercial insurance coverage in 2H 2023. The Company is also in negotiations with Medicaid payers in key priority states with the goal of attaining reimbursement for OLPRUVA™ Medicaid patients starting in Q3 2023.

Patient Support
Acer has also established and staffed its patient support program, Navigator by Acer Therapeutics, that includes a suite of services designed to provide streamlined and efficient prescription management — including benefits verification, education, and home delivery — and personalized support for OLPRUVA™ patients.

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).¹ 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. OLPRUVA™ (sodium phenylbutyrate) for oral suspension. Prescribing information. Newton, MA: Acer Therapeutics Inc.

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 timing thereof, the 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 and sales 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

NEWTON, MA – March 27, 2023 – 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 reported financial results for Q4 and full year ended December 31, 2022, and provided an update on the Company’s recent corporate developments.

“2022 marked Acer’s first U.S. Food and Drug Administration (FDA) product approval, for OLPRUVA™ (sodium phenylbutyrate), an innovative and responsibly priced treatment option for certain people with urea cycle disorders (UCDs) involving deficiencies of carbamylphosphate synthetase (CPS), ornithine transcarbamylase (OTC), or argininosuccinic acid synthetase (AS),” commented Chris Schelling, CEO and Founder of Acer. “We remain committed to our mission to provide transformative treatments to underserved and overlooked patients with rare and life-threatening diseases and will continue to focus our resources on launch preparation for OLPRUVA™ as well as continued pivotal Phase 3 clinical trial evaluation of EDSIVO™ for vEDS, both of which are subject to additional capital.”

Q4 2022 and Recent Highlights

• OLPRUVA™ (sodium phenylbutyrate) for oral suspension
  • In October 2022, Acer was issued a Notice of Allowance from the US Patent and Trademark Office (USPTO) for US patent application No. 16/624,834 (now issued as US Patent No. 11,517,547) for claims related to a kit comprising a combination therapeutic product composed of sodium phenylbutyrate or glycerol phenylbutyrate and sodium benzoate
  • In December 2022, Acer announced FDA approval of OLPRUVA™ (sodium phenylbutyrate) for oral suspension, 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 UCDs, involving deficiencies of CPS, OTC or AS. OLPRUVA™ is not used to treat rapid increase of ammonia in the blood (acute hyperammonemia), which can be life-threatening and requires emergency medical treatment. More information is available at www.OLPRUVA.com
  • In March 2023, Acer announced an update on its OLPRUVA™ U.S. commercial launch activities, including the ongoing addition of commercial and medical affairs resources, the introduction of its OLPRUVA™ Navigator by Acer Therapeutics patient support service, a predictable and responsible price commitment, and anticipated drug availability by early July 2023 (subject to additional capital)
  • In March 2023, Acer announced results from a survey designed to quantify preferences of healthcare providers for Urea Cycle Disorders (UCDs) presented at the Society for Inherited Metabolic Disorders (SIMD) Annual Meeting. The authors concluded that optimizing nitrogen-binding medications for UCD treatment to facilitate and encourage increased patient adherence through masking taste/odor and/or enhancing other aspects of the patient experience may support improved outcomes in UCDs
• EDSIVO™ (celiprolol)
  • In October 2022, Acer announced that the USPTO issued a Notice of Allowance for Acer’s patent application No. 16/930,208 and subsequently issued on December 13, 2022, as US Patent #11,523,997, for claims related to certain methods of treating vascular Ehlers-Danlos syndrome (vEDS) with celiprolol
• ACER-801 (osanetant)
  • In March 2023, Acer announced that topline results from Acer’s Phase 2a proof of concept clinical trial to evaluate ACER-801 (osanetant) as a potential treatment for moderate to severe Vasomotor Symptoms (VMS) associated with menopause showed that ACER-801 was safe and well-tolerated but did not achieve statistical significance when evaluating ACER-801’s ability, when compared to placebo, to decrease the frequency or severity of hot flashes in postmenopausal women. As a result, Acer is pausing the ACER-801 program until Acer has conducted a thorough review of the full data set
• Corporate
  • Ended Q4 2022 with $2.3 million in cash and cash equivalents. Acer believes its cash and cash equivalents available at December 31, 2022, together with the gross proceeds of $7.0 million from a second term loan with SWK Funding LLC which closed on January 31, 2023, $4.1 million from  Acer’s ATM facility subsequent to December 31, 2022, and $2.7 million from a sale of securities (including pursuant to a registered direct offering of shares of common stock and prefunded warrants) which closed on March 24, 2023, will be sufficient to fund Acer’s anticipated operating and capital requirements into the middle of Q2 2023

Anticipated Milestones (Subject to Available Capital)

• Q2 2023: Acer intends to continue to add resources to establish its commercial and medical affairs presence in the U.S. in support of its OLPRUVA™ launch expected in Q2 2023 
• Q2 2023: Negotiations with the major commercial payers and state Medicaid organizations regarding access for OLPRUVA™ are ongoing, and representatives from Acer’s OLPRUVA™ Navigator by Acer Therapeutics patient support service are expected to begin accepting prescriptions in late Q2 2023
• Q2 2023: Acer expects OLPRUVA™ wholesale acquisition cost (WAC) pricing to be listed publicly in Q2 2023
• Early July 2023: Acer anticipates OLPRUVA™ drug availability in early July 2023

• Q4 2023: Acer anticipates completing enrollment in its ongoing, pivotal Phase 3 DiSCOVER trial of EDSIVO™ (celiprolol) in patients with COL3A1-positive vEDS. The double-blind portion of the DiSCOVER trial is designed to end if statistical significance is reached at an interim analysis which occurs at accrual of 28 vEDS-related events, estimated to occur as early as approximately 18 months after completion of full enrollment, or after accrual of 46 vEDS-related clinical events
• Acer intends to explore additional lifecycle opportunities for OLPRUVA™ (sodium phenylbutyrate) in various disorders where proof of concept data exists, including in Maple Syrup Urine Disease (MSUD), Pyruvate Dehydrogenase Complex Deficiency (PCDC), rare pediatric epilepsies and various liver disorders

Q4 and Full Year 2022 Financial Results

Cash Position. Cash and cash equivalents were $2.3 million as of December 31, 2022, compared to $12.7 million as of December 31, 2021. Acer believes its cash and cash equivalents as of December 31, 2022, together with the gross proceeds of $7.0 million from a second term loan with SWK Funding LLC which closed on January 31, 2023, $4.1 million from Acer’s ATM facility subsequent to December 31, 2022, and $2.7 million from a sale of securities (including pursuant to a registered direct offering of shares of common stock and prefunded warrants) which closed on March 24, 2023, will be sufficient to fund its currently anticipated operating and capital requirements into the middle of Q2 2023.

Research and Development Expenses. Research and development expenses were $2.6 million, net of collaboration funding of $1.0 million, for the three months ended December 31, 2022, as compared to $1.7 million, net of collaboration funding of $1.3 million, for the three months ended December 31, 2021. Research and development expenses for the three months ended December 31, 2022 were comprised of $1.1 million related to ACER-001, offset by $1.0 million of collaboration funding; $1.2 million related to ACER-801; $1.0 million related to EDSIVO™; and $0.3 million related to other development activities. Research and development expenses were $11.9 million, net of collaboration funding of $7.8 million, for the year ended December 31, 2022, as compared to $6.5 million, net of collaboration funding of $6.1 million, for the year ended December 31, 2021. This increase of $5.4 million was primarily due to increases in employee-related expenses and expenses related to clinical studies, partially offset by the increase in recognition of contra-expense from the collaboration funding from Acer’s Collaboration and License Agreement with Relief Therapeutics Holding AG (Relief) for the development and commercialization of OLPRUVA™ (Collaboration Agreement).

General and Administrative Expenses. General and administrative expenses were $2.6 million, net of collaboration funding of $1.2 million, for the three months ended December 31, 2022, as compared to $3.1 million, net of collaboration funding of $1.6 million, for the three months ended December 31, 2021. General and administrative expenses were $12.7 million, net of collaboration funding of $8.2 million, for the year ended December 31, 2022, as compared to $10.7 million, net of collaboration funding of $3.2 million, for the year ended December 31, 2021. This increase of $2.0 million was primarily due to increases in precommercial activities, employee-related expenses, professional services, as well as information technology, partially offset by the increase in the recognition of contra-expense from the collaboration funding from the Collaboration Agreement with Relief.

Net Loss. Net loss for the three months ended December 31, 2022 was $9.4 million, or $0.54 net loss per share (basic and diluted), compared to a net loss of $4.4 million, or $0.31 net loss per share (basic and diluted), for the three months ended December 31, 2021. Net loss for the year ended December 31, 2022 was $26.2 million, or $1.66 net loss per share (basic and diluted), compared to a net loss of $15.4 million, or $1.08 net loss per share (basic and diluted), for the year ended December 31, 2021.

For additional information, please see Acer’s Annual Report on Form 10-K filed today with the SEC.

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.  

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 plans for the commercialization of OLPRUVA™ for oral suspension in the U.S. for the treatment of certain patients with UCDs involving deficiencies of CPS, OTC, or AS, including negotiations with commercial payers and Medicaid organizations regarding access as well as the timing of drug availability and the expected commercial launch, statements about plans and potential milestones for the continued clinical development of OLPRUVA™ in other indications, statements about plans and potential milestones for the continued clinical development of EDSIVO™ for treatment of vEDS in patients with a confirmed type III collagen (COL3A1) mutation, statements about plans for the development of ACER-801, statements about our anticipated 2023 milestones, and statements about our capital requirements and sufficiency and duration of our current cash and cash equivalents. 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 as well as EDSIVO™ and ACER-801) 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 our 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 Contact

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

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

NEWTON, MA – March 22, 2023 – 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@medinfo+1-844-902-6100

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

NEWTON, MA – March 22, 2023 – 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 that it has entered into a definitive agreement for the purchase and sale of 2,920,306 shares of the Company’s common stock (or common stock equivalents) at a purchase price of $0.916 per share of common stock (or common stock equivalent) in a registered direct offering priced at-the-market under Nasdaq rules. In addition, in a concurrent private placement, the Company will issue warrants to purchase up to 2,920,306 shares of common stock. The warrants will have an exercise price of $0.791 per share, will be exercisable immediately following issuance and have a term of five and one-half years from the issuance date.

H.C. Wainwright & Co. is acting as the exclusive placement agent for the offering.

The closing of the offering is expected to occur on or about March 24, 2023, subject to the satisfaction of customary closing conditions. The gross proceeds to the Company from the offering are expected to be approximately $2.675 million, before deducting the placement agent’s fees and other offering expenses payable by the Company. The Company intends to use the net proceeds from this offering for general corporate purposes and working capital.

The shares of common stock described above (but not the warrants issued in the concurrent private placement or the shares of common stock underlying such warrants) are being offered by the Company pursuant to a “shelf” registration statement on Form S-3 (File No. 333-261342) initially filed with the Securities and Exchange Commission (the “SEC”) on November 24, 2021 and declared effective by the SEC on December 7, 2021. The offering of the shares of common stock is made only by means of a prospectus, including a prospectus supplement, forming a part of the effective registration statement. A final prospectus supplement and accompanying prospectus relating to the registered direct offering will be filed with the SEC. Electronic copies of the final prospectus supplement and accompanying prospectus may be obtained, when available, on the SEC’s website at http://www.sec.gov or by contacting H.C. Wainwright & Co., LLC at 430 Park Avenue, 3rd Floor, New York, NY 10022, by phone at (212) 865-5711 or e-mail at placements@hcwco.com.

The warrants described above were offered in a private placement under Section 4(a)(2) of the Securities Act of 1933, as amended (the “Securities Act”), and, along with the shares of common stock underlying the warrants, have not been registered under the Securities Act, or applicable state securities laws. Accordingly, the warrants and underlying shares of common stock may not be reoffered or resold in the United States except pursuant to an effective registration statement or an applicable exemption from the registration requirements of the Securities Act and such applicable state securities laws.

This press release shall not constitute an offer to sell or a solicitation of an offer to buy these securities, nor shall there be any sale of these securities in any state or other jurisdiction in which such offer, solicitation or sale would be unlawful prior to the registration or qualification under the securities laws of any such state or other jurisdiction.

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.

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 regarding the consummation of the offering, the satisfaction of closing conditions and the use of proceeds from the offering, as well as statements about the continued development of ACER-801 for treatment of VMS or other indications, the continued development of EDSIVO™, and launch preparations for OLPRUVA™. Our pipeline products (including ACER-801) 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, market and other conditions, the availability of financing to fund our pipeline product development programs, commercialization efforts 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@medinfo+1-844-902-6100

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

NEWTON, MA – March 17, 2023 – 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 that topline results from its Phase 2a proof of concept clinical trial to evaluate ACER-801 (osanetant) as a potential treatment for moderate to severe Vasomotor Symptoms (VMS) associated with menopause showed that ACER-801 was safe and well-tolerated but did not achieve statistical significance when evaluating ACER-801’s ability to decrease the frequency or severity of hot flashes in postmenopausal women.

As a result, Acer is pausing the ACER-801 program until Acer has conducted a thorough review of the full data set. Concurrently, Acer is continuing to focus on preparation for its commercial launch of OLPRUVA™ (sodium phenylbutyrate) for oral suspension for the treatment of urea cycle disorders (UCDs) involving deficiencies of carbamylphosphate synthetase (CPS), ornithine transcarbamylase (OTC), or argininosuccinic acid synthetase (AS), and the ongoing pivotal Phase 3 clinical evaluation of EDSIVO™ (celiprolol) for vascular Ehlers-Danlos Syndrome (vEDS) in patients with a confirmed type III collagen (COL3A1) mutation, subject in each instance to availability of additional capital beyond early in Q2 2023.

“We are surprised and disappointed the Phase 2a trial did not meet its efficacy objectives in treating VMS given the extensive body of non-clinical and clinical evidence previously generated,” stated Chris Schelling, CEO and Founder of Acer. “We intend to conduct a comprehensive analysis of the totality of the clinical trial data – including the pharmacokinetic data, which has not yet been analyzed – which will inform our path forward for the program, including our collaborations for prostate cancer and post-traumatic stress disorder (PTSD). We wish to thank the patients, investigators and partners who participated in this clinical trial. We remain committed to our mission to provide transformative treatments to underserved and overlooked patients with rare and life-threatening diseases and will continue to focus our resources on launch preparation for our FDA-approved product, OLPRUVA™, for oral suspension for the treatment of UCDs involving deficiencies of CPS, OTC or AS, as well as our pivotal Phase 3 clinical trial of EDSIVO™ for vEDS.”

About ACER-801 (osanetant)
ACER-801 (osanetant) is an investigational non-hormonal, neurokinin 3 receptor (NK3R) antagonist being studied for the potential treatment of patients with Vasomotor Symptoms (VMS), prostate cancer and post-traumatic stress disorder (PTSD). In December 2018, Acer entered into an exclusive license agreement with Sanofi to acquire worldwide rights to ACER-801 (osanetant). In the Phase 2a study, forty-nine postmenopausal women aged 40-65 who experienced moderate to severe hot flashes were randomized 1:1:1:1 and received either twice daily 50 mg, 100 mg, 200 mg of ACER-801 or placebo over a 14-day treatment period, followed by a 14-day safety follow-up assessment. Primary endpoints were safety and pharmacokinetics, with efficacy compared to placebo as a secondary endpoint.

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); ACER-801 (osanetant) for treatment of Vasomotor Symptoms (VMS), post-traumatic stress disorder (PTSD) and prostate cancer; and EDSIVO™ (celiprolol) for treatment of vascular Ehlers-Danlos syndrome (vEDS) in patients with a confirmed type III collagen (COL3A1) mutation. For more information, visit www.acertx.com.

Acer currently believes that its existing cash and cash equivalents will be sufficient to fund its anticipated operating and capital requirements into early in the second quarter of 2023. Acer will require additional financing 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, as well as to complete development and seek to obtain marketing approval of Acer’s other product candidates and, if approved, to commercialize such other product candidates. There can be no assurance that Acer will be able to obtain needed capital on acceptable timing and terms, or at all.  A failure in this regard could force Acer to delay, limit, reduce or terminate its product development, other operations or commercialization efforts, or to suspend or restructure its business.

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 the continued development of ACER-801 for treatment of VMS or other indications, the continued development of EDSIVO™, and launch preparations for OLPRUVA™. Our pipeline products (including ACER-801) 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 pipeline product development programs, commercialization efforts 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@medinfo+1-844-902-6100

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

NEWTON, MA – March 15, 2023 – 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 will be presented from a survey designed to quantify preferences of healthcare providers for Urea Cycle Disorders (UCDs) at the upcoming 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 will be available on Acer’s website following the poster presentation at SIMD on March 19 by Dr. Robert Steiner (University of Wisconsin School of Medicine and Public Health) at https://www.acertx.com/publications-and-presentations/.

Poster #97: Quantifying Preferences for Urea Cycle Disorder Treatments Using a Discrete-Choice Experiment
This poster summarizes results from a web-based, quantitative survey study using a discrete choice experiment (DCE) methodology.  This study sought to capture the perspectives of healthcare providers (HCPs) with experience treating UCDs to quantify the attributes of nitrogen-binding medications (such as sodium phenylbutyrate and glycerol phenylbutyrate) for UCDs that may influence overall prescription and patient adherence.

“OLPRUVA™¹ 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 look forward to the presentation of the survey results at SIMD as we continue to prepare for the launch of OLPRUVA™, and to the delivery of an important alternative treatment option to those facing the unmet needs of existing therapies.”

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^2,3

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 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.

OLPRUVA™ Program Update
Acer also provided an update on its commercial launch activities for OLPRUVA™ in advance of the SIMD Annual Meeting, where it will be exhibiting in booths 312 and 213. To support the launch of OLPRUVA™ in Q2 2023, the company is actively adding resources to establish its commercial and medical affairs presence in the U.S.  As a part of its OLPRUVA™ commercialization strategy, Acer has recently introduced its patient support service, OLPRUVA™ Navigator by Acer Therapeutics, that is designed to assist UCD patients with support, access, education, and patient adherence to treatment. Representatives will begin accepting prescriptions in late Q2 2023. Acer is also actively engaged in negotiations regarding access for OLPRUVA™ with the major commercial payers and state Medicaid organizations.

In connection with the company’s ongoing support for the rare disease patient community, Acer has established a pricing strategy that reflects its commitment to deliver innovative treatments that are responsibly priced and accessible to those in need.  As a result, Acer intends to price OLPRUVA™ competitively, at a significant discount to the currently available commercial product RAVICTI®, while implementing predictable pricing that will not increase beyond the rate of inflation.  The company also plans to invest a portion of OLPRUVA™ revenue back into additional solutions aimed at improving outcomes for UCD patients. More information will be available at OLPRUVA.com.

“We are proud that we can provide OLPRUVA™ — an innovative, responsibly priced treatment option — to patients with UCDs. And we are 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,” commented Chris Schelling, CEO and Founder of Acer. “While our future plans are subject to the availability of working capital moving forward, we feel strongly that Acer is well positioned to access additional sources of capital to fund day-to-day operations and OLPRUVA’s™ launch requirements.”

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).¹ Please see Important Safety Information and full Prescribing Information, including Patient Information.

About Acer Therapeutics Inc.
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); ACER-801 (osanetant) for treatment of Vasomotor Symptoms (VMS), Post-traumatic Stress Disorder (PTSD) and prostate cancer; EDSIVO™ (celiprolol) for treatment of vascular Ehlers-Danlos syndrome (vEDS) in patients with a confirmed type III collagen (COL3A1) mutation; and ACER-2820 (emetine), a host-directed therapy against a variety of viruses, including cytomegalovirus, Zika, dengue, Ebola and COVID-19. For more information, visit www.acertx.com. In March 2021, Acer entered into a Collaboration and License Agreement with RELIEF THERAPEUTICS Holding SA for development and commercialization of OLPRUVA™ (ACER-001) in which Acer retains development and commercialization rights in the U.S., Canada, Brazil, Turkey, and Japan. For more information, visit www.acertx.com.

References

1. OLPRUVA^TM (sodium phenylbutyrate) for oral suspension. Prescribing information. Newton, MA: Acer Therapeutics Inc.
2. 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
3. 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 pipeline products 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 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@medinfo+1-844-902-6100

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

NEWTON, MA – February 13, 2023 – 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 full enrollment of its Phase 2a proof of concept trial of ACER-801 (osanetant), a novel, non-hormonal, neurokinin 3 receptor (NK3R) antagonist, being investigated as a potential treatment option for moderate to severe Vasomotor Symptoms (VMS) associated with menopause. Topline results from this trial are expected in mid-March 2023.

The Phase 2a randomized, double-blind, placebo-controlled, dose-ranging trial of ACER-801 is designed to evaluate the safety, pharmacokinetics (PK) and efficacy of ACER-801 in 48 postmenopausal women aged 40-65 who experience moderate to severe hot flashes. Subjects were randomized 1:1:1:1 and receive twice daily doses of either 50mg, 100mg, 200mg of ACER-801 or placebo over a 14-day treatment period, followed by a 14-day safety follow-up assessment. Results from this trial could provide proof of concept data in postmenopausal women and could inform ACER-801 dosing and a development path forward in patients with induced Vasomotor Symptoms (iVMS).

About VMS, iVMS and ACER-801
VMS are caused by a disruption in sex hormone signaling in the brain, resulting in menopausal-like symptoms (hot flashes, night sweats, etc.) and most often occur in women during menopausal transition or in menopause (MR-VMS). VMS leads to significant impact on patient quality of life, including sleep deprivation, lack of focus, and anxiety/depression. VMS can also be induced (iVMS) by anti-androgen and anti-estrogen cancer therapies and surgical procedures altering sex hormone production.^1,2 VMS are caused by low estrogen levels leading to increased stimulatory signaling of NKB on the Kisspeptin/Neurokinin B/Dynorphin (KNDy) neurons in the hypothalamus. A non-hormonal treatment to manage VMS is needed, especially in patients where estrogen is contraindicated or not well tolerated.

iVMS are well documented with the use of cancer therapies and certain surgical procedures. Symptoms such as hot flashes can appear immediately and be severe. Cancer therapy side effects can lead to treatment non-adherence which increases the mortality risk and/or shortens the time to recurrence. Acer also believes a treatment for iVMS is needed to help certain cancer patients to be more likely to start and stay on critical cancer therapies.

ACER-801 (osanetant) is a novel, non-hormonal, NK3R antagonist that could offer a potential treatment option with meaningful improvement of VMS for patients with iVMS by blocking the stimulatory signaling of NKB on the KNDy neurons. Direct human safety evidence is available from 23 completed Phase 1 and 2 studies in which approximately 400 healthy subjects and 820 patients were treated with osanetant for schizophrenia, depression and other indications. Data from these studies indicated no major safety concerns after single-dose and repeat-dose administration.³ ACER-801 is orally bioavailable⁴ and readily crosses the blood-brain barrier.⁵ Acer believes that several disorders involving the hypothalamus-pituitary-gonadal axis could be investigated for potential benefit from treatment with an NK3R antagonist.

ACER-801 is an investigational product candidate which has not been approved by FDA or any other regulatory authority. There is no guarantee that this product candidate will receive regulatory authority approval in any territory or become commercially available for any indications.

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); ACER-801 (osanetant) for treatment of Vasomotor Symptoms (VMS), Post-traumatic Stress Disorder (PTSD) and prostate cancer; EDSIVO™ (celiprolol) for treatment of vascular Ehlers-Danlos syndrome (vEDS) in patients with a confirmed type III collagen (COL3A1) mutation; and ACER-2820 (emetine), a host-directed therapy against a variety of viruses, including cytomegalovirus, Zika, dengue, Ebola and COVID-19. For more information, visit www.acertx.com.

References

1. Kotsopoulos J, Huzarski T, Gronwald J, Moller P, Lynch HT, Neuhausen SL, et al. Hormone replacement therapy after menopause and risk of breast cancer in BRCA1 mutation carriers: a case-control study. Breast Cancer Research and Treatment 2016;155(2):365–73.
2. Guidozzi F. Hormone therapy after prophylactic risk-reducing bilateral salpingo-oophorectomy in women who have BRCA gene mutation. Climacteric 2016;19(5): 419–22.
3. Meltzer H, et al. Placebo-controlled evaluation of four novel compounds for the treatment of schizophrenia and schizoaffective disorder. June 2004; 161(6):975-84.
4. Single and Repeated Ascending Oral Dose Tolerability Study of SR142801 in Healthy Male Subjects. Sanofi Clinical Study Report February 2001.
5. Gueudet C, et al. Blockade of neurokinin3 receptors antagonizes drug-induced population response and depolarization block of midbrain dopamine neurons in guinea pigs. Synapse. 1999 Jul;33(1):71-9.

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 the continued development of ACER-801 for treatment of iVMS and our expected 2023 milestones. Our pipeline products (including ACER-801) 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 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 Contact
Jim DeNike
Acer Therapeutics Inc.
jdenike@medinfo+1-844-902-6100

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

NEWTON, MA – January 09, 2023 – 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 a corporate update and provided anticipated key development milestones for 2023.

“The U.S. approval of OLPRUVA™ (sodium phenylbutyrate) for oral suspension by the U.S. Food and Drug Administration (FDA) is a culmination of Acer’s collective efforts and ongoing dedication to develop and provide new treatments to patients suffering from rare diseases. Moreover, OLPRUVA™’s approval marks a significant milestone for patients in need, offering a new, responsibly priced sodium phenylbutyrate treatment option, that will be supported by Navigator by Acer Therapeutics, our patient services program designed to support patients and caregivers,” stated Chris Schelling, CEO and Founder of Acer. “Our commitment to patients is the cornerstone of our mission, and we are proud to have secured our first FDA approval. We look forward to providing further updates in due course as the commercial launch of OLPRUVA™ progresses.”

Mr. Schelling continued, “In addition to the approval of OLPRUVA™, our clinical team has been diligently executing on the clinical trials for ACER-801, being investigated in Vasomotor Symptoms (VMS), Post-traumatic Stress Disorder (PTSD) and now prostate cancer. We are eager to report the topline results from our ongoing Phase 2a trial of ACER-801 in moderate to severe VMS in post-menopausal women in Q1 of 2023. These trial results will provide important insight into ACER-801’s therapeutic potential in induced VMS (iVMS). Additionally, our pivotal Phase 3 trial of EDSIVO™ (celiprolol) in COL3A1-positive vascular Ehlers-Danlos Syndrome (vEDS) patients remains ongoing as planned, and we look forward to providing an update on full enrollment later this year.”

Review of Acer’s Pipeline

• OLPRUVA™ (sodium phenylbutyrate) for oral suspension
  • On December 27, 2022, Acer announced that the U.S. Food and Drug Administration (FDA) approved OLPRUVA™ (sodium phenylbutyrate) for the treatment of certain patients with UCDs involving deficiencies of CPS, OTC or AS
  • OLPRUVA™ 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 UCDs, involving deficiencies of CPS, OTC or AS. OLPRUVA™ is not used to treat rapid increase of ammonia in the blood (acute hyperammonemia), which can be life-threatening and requires emergency medical treatment. For additional Important Safety Information, see full Prescribing Information, Patient Information and discuss with your doctor
  • Formation of Navigator by Acer Therapeutics: Navigator is Acer’s patient access program, a suite of integrated patient support services designed to help provide more convenient access to OLPRUVA™. The Navigator by Acer Therapeutics support services are intended to facilitate support, education, and treatment adherence to the UCD patient community

• ACER-801 (osanetant)
  • Acer’s ongoing Phase 2a randomized, double-blind, placebo-controlled, dose-ranging trial of ACER-801 (osanetant) for the treatment of moderate to severe VMS in post-menopausal women is expected to readout in Q1 2023. The data from the Phase 2a trial will inform Acer’s development path for ACER-801 (osanetant) in iVMS
  • In October 2022, Acer announced the expansion of its ACER-801 (osanetant) program into PTSD, a disorder that affects over 12 million adults in the U.S. each year.¹ Related to this program expansion, Acer licensed the worldwide exclusive rights and corresponding intellectual property portfolio from Emory University based on preclinical data that showed osanetant’s ability to block fear memory consolidation in mice
  • Concurrent with this expansion, the US Department of Defense (DoD) awarded a $3 million grant to the University of North Carolina Institute for Trauma Recovery to support a proposed investigator-sponsored Phase 2 trial evaluating osanetant in 180 trauma patients. The randomized, placebo-controlled Phase 2 trial is currently expected to begin in Q2 2023
  • In January 2023, Acer announced the initiation of two Phase 2, single-arm investigator-sponsored trials evaluating ACER-801 (osanetant) in men with adenocarcinoma of the prostate. The POSH-MAP (Pilot of Osanetant for Severity of Hot Flashes in Men with Adenocarcinoma of the Prostate) and PORT-MAP (Pilot of Osanetant to Reduce Testosterone in Men with Adenocarcinoma of the Prostate) trials are being sponsored and conducted by The University of Kansas Cancer Center in partnership with Acer

• EDSIVO™ (celiprolol)
  • Acer’s ongoing Phase 3 DiSCOVER trial is a randomized, double-blind, placebo-controlled efficacy trial designed to evaluate EDSIVO™ (celiprolol) in patients with genetically confirmed COL3A1-positive vascular Ehlers-Danlos Syndrome (vEDS)

Expected 2023 Development Milestones (Subject to Available Capital)

• Q1 2023: Acer expects to announce topline results from its ongoing Phase 2a randomized, double-blind, placebo-controlled, dose-ranging trial of ACER-801 (osanetant) for the treatment of moderate to severe VMS in post-menopausal women
• Q2 2023: Acer expects initiation of the UNC investigator-sponsored trial to evaluate the potential for ACER-801 (osanetant) to reduce the frequency and severity of PTSD and other trauma related disorders
• Q4 2023: Acer anticipates completing enrollment in its ongoing, pivotal Phase 3 DiSCOVER trial of EDSIVO™ (celiprolol) in patients with COL3A1-positive vEDS. The double-blind portion of DiSCOVER trial is intended to end if statistical significance is reached at an interim analysis which occurs at accrual of 28 vEDS-related events, estimated to occur as early as approximately 18 months after completion of full enrollment, or after accrual of 46 vEDS-related clinical events
• Acer intends to explore additional lifecycle opportunities for OLPRUVA™ (sodium phenylbutyrate) in various disorders where proof of concept data exists, including in Maple Syrup Urine Disease (MSUD), Pyruvate Dehydrogenase Complex Deficiency (PCDC), rare pediatric epilepsies and various liver disorders

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); ACER-801 (osanetant) for treatment of induced Vasomotor Symptoms (iVMS), Post-traumatic Stress Disorder (PTSD) and prostate cancer; EDSIVO™ (celiprolol) for treatment of vascular Ehlers-Danlos syndrome (vEDS) in patients with a confirmed type III collagen (COL3A1) mutation; and ACER-2820 (emetine), a host-directed therapy against a variety of viruses, including cytomegalovirus, Zika, dengue, Ebola and COVID-19. For more information, visit www.acertx.com.

References

1. National Center for PTSD.  How Common is PTSD in Adults?

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 the role we believe ACER-801 could play in reducing the frequency and severity of PTSD, the planned clinical evaluation of ACER-801 for such indication, the continued development of ACER-801 for treatment of iVMS and our expected 2023 milestones. Our pipeline products (including ACER-801) 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 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 Contact

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

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

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NEWTON, MA – Jan. 5, 2023 –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 the initiation of two Phase 2, single-arm investigator-sponsored trials evaluating ACER-801 (osanetant) in men with adenocarcinoma of the prostate. The POSH-MAP (Pilot of Osanetant for Severity of Hot Flashes in Men with Adenocarcinoma of the Prostate) and PORT-MAP (Pilot of Osanetant to Reduce Testosterone in Men with Adenocarcinoma of the Prostate) trials are being sponsored and conducted by The University of Kansas Cancer Center in partnership with Acer.

POSH-MAP Trial
The POSH-MAP trial will evaluate the ability of ACER-801 to reduce hot flash frequency and severity and improve quality of life measures in men with prostate cancer following 28 days of therapy. Approximately 10 participants will receive 200mg of osanetant twice daily. Following the completion of treatment on day 28 participants will re-test hormone levels and report final patient outcome measures. More information on this trial can be found here.  

“Prostate cancer’s responsiveness to hormone-based treatments that decrease testosterone levels such as leuprolide or other forms of androgen deprivation therapy (ADT) have established them as the standard of care for treatment of prostate cancer,” said Elizabeth Wulff-Burchfield, MD, Principal Investigator of the POSH-MAP trial, Divisions of Medical Oncology and Palliative Medicine, Department of Medicine, The University of Kansas Health System. “However, for men on ADT, this causes a secondary decline in estrogen that results in dysfunctional thermoregulation and development of vasomotor symptoms (VMS) which can affect quality of life and lead to treatment non-adherence.¹ With clinical data showing the potential of neurokinin 3 receptor (NK3R) antagonism to reduce menopausal related VMS in women,² we look forward to evaluating the ability of ACER-801 to help mediate ADT-related VMS in men with prostate cancer.”

PORT-MAP Trial
The second trial, PORT-MAP, will evaluate the ability of ACER-801 to suppress testosterone production in men with prostate cancer within 28 days prior to a planned prostatectomy. Approximately 10 participants will receive 200mg of osanetant twice daily for 28 days, followed by a one week wash out period. Following the one week wash out period, patients will undergo a prostatectomy between days 35-39. The overall effect of osanetant on testosterone levels and the proportion of men achieving castrate levels of testosterone (<50ng/ml) will be assessed, with hormone level assessment occurring on days 2, 3, 14, 28 and day 77. More information on this trial can be found here.

“Early studies in healthy male volunteers treated with various NK3R antagonists have shown an inhibitory effect on the levels of testosterone,” said William Parker, MD, Principal Investigator, Division of Urologic Oncology, Department of Urology, The University of Kansas Health System. “However, the ability of NK3R antagonists to reduce testosterone to castrate levels in prostate cancer patients has not been evaluated to date. Based on these data, we look forward to evaluating the potential of ACER-801 and its ability to reduce testosterone in men with prostate cancer.”

“We are pleased to partner with The University of Kansas Cancer Center to evaluate ACER-801 in men with prostate cancer currently receiving ADT treatment in these investigator-sponsored trials,” said Adrian Quartel, MD, FFPM, Chief Medical Officer of Acer. “With the recent expansion of our ACER-801 (osanetant) program into stress-related trauma disorders, including PTSD, and now men with prostate cancer, we look forward to the ongoing evaluation of ACER-801 in multiple indications and reporting topline results from our ongoing Phase 2a trial for the treatment of moderate to severe VMS in post-menopausal women in Q1 2023.”

Rationale for ACER-801 (osanetant) NK3R Antagonist Evaluation in Prostate Cancer 
Prostate cancer is a hormonally driven cancer, and the management of this disease for many men is through suppression of testosterone production – called androgen deprivation therapy (ADT). Currently, most men on ADT are treated with medications that suppress hormone production which can cause dysfunctional thermoregulation and development of vasomotor symptoms (VMS), also known as hot flashes. Up to 75% of men on ADT experience VMS, resulting in high rates of distress and ADT treatment noncompliance, with approximately 20% of men with high-risk prostate cancer prematurely discontinuing ADT.³ Early pharmacokinetic studies in men and women with various NK3R antagonists have shown an inhibitory effect on the levels of luteinizing hormone and testosterone. However, the degree of effect relative to a therapeutic goal of castrate levels of testosterone (≤ 50ng/mL) remains unexplored.^1,2 A non-hormonal treatment to lower testosterone levels and manage induced VMS is needed as estrogen is contraindicated for the management of VMS in patients with hormone-positive tumors, including breast and prostate tumors.

ACER-801 is an investigational product candidate which has not been approved by FDA or any other regulatory authority. There is no guarantee that this product candidate will receive regulatory authority approval in any territory or become commercially available for any indications.

About Acer Therapeutics Inc.
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); ACER-801 (osanetant) for treatment of induced Vasomotor Symptoms (iVMS), Post-traumatic Stress Disorder (PTSD) and prostate cancer; EDSIVO™ (celiprolol) for treatment of vascular Ehlers-Danlos syndrome (vEDS) in patients with a confirmed type III collagen (COL3A1) mutation; and ACER-2820 (emetine), a host-directed therapy against a variety of viruses, including cytomegalovirus, Zika, dengue, Ebola and COVID-19. For more information, visit www.acertx.com.

References

1. Challapalli, Amarnath, et al. “Evaluating the Prevalence and Predictive Factors of Vasomotor and Psychological Symptoms in Prostate Cancer Patients Receiving Hormonal Therapy: Results from a Single Institution Experience.” Clinical and Translational Radiation Oncology, Elsevier, 21 Mar. 2018
2. Prague J. et al. Neurokinin 3 receptor antagonism rapidly improves vasomotor symptoms with sustained duration of action. Menopause. 2018 Aug; 25(8): 862–869.
3. Trinity Partners 2020

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 the role we believe ACER-801 could play in mediating ADT-related VMS in men with prostate cancer and reducing testosterone levels in men with prostate cancer, the planned clinical evaluation of ACER-801 for such indications, plans with respect to the POSH-MAP trial and PORT-MAP trial, including enrollment, timing, outcome and participants, the continued development of ACER-801 for multiple indications, and our plans, including timing, to report topline results from our ongoing Phase 2a trial for the treatment of moderate to severe VMS in post-menopausal women. Our pipeline products (including ACER-801) 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 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.

Acer Contacts

Corporate contact:
Jim DeNike
Acer Therapeutics Inc.
jdenike@acertx.com
+1-844-902-6100

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

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