Acer Therapeutics Announces Initiation of its Pivotal Phase 3 DiSCOVER Trial of EDSIVO™ (celiprolol) for the Treatment of Vascular Ehlers-Danlos Syndrome

Acer Therapeutics Inc. (Nasdaq: ACER), a clinical stage pharmaceutical company focused on the acquisition, development and commercialization of therapies for serious rare and life-threatening diseases with significant unmet medical needs, yesterday announced the initiation of patient screening in its Phase 3 DiSCOVER (Decentralized Study of Celiprolol ovEDS-related Event Reduction) clinical trial of EDSIVO™ (celiprolol) for the treatment of patients with COL3A1-positive vascular Ehlers-Danlos Syndrome (VEDS).

“With no approved treatments available for VEDS, ongoing clinical evaluation of EDSIVO™ (celiprolol) is an important step that we hope could lead to the first available treatment option for this fatal disorder,” said Adrian Quartel, MD, FFPM, Chief Medical Officer of Acer. “The innovative, decentralized study design will allow for greater access and ease of administration for VEDS patients, mobile nurses, remote clinical research coordinators and investigators. We’d like to thank all the patients, their family members, the advocacy groups and clinicians who have expressed interest in learning more about participating in the study, and look forward to rapidly enrolling the trial.”

The DiSCOVER trial is a prospective, Phase 3, randomized, double-blind, placebo-controlled efficacy trial designed to evaluate EDSIVO™ (celiprolol) in patients with genetically confirmed COL3A1-positive VEDS using a decentralized clinical trial design and an independent adjudication committee. The primary objective of the trial is to determine whether EDSIVO™ (celiprolol) reduces the occurrence of VEDS-related clinical events requiring medical attention, including fatal and non-fatal cardiac or arterial events, uterine rupture, intestinal rupture, and/or unexplained sudden death, relative to placebo as measured by time to event. Acer plans to enroll approximately 150 COL3A1-positive VEDS patients, all in the U.S., randomized 2:1 to receive either EDSIVO™ (celiprolol) or placebo, respectively. Individuals seeking more information on the EDSIVO™ (celiprolol) pivotal clinical trial are invited to visit

Once the trial is fully enrolled, the duration of the DiSCOVER trial is currently estimated to be up to approximately 3.5 years to completion (based on statistical power calculations and number of primary events), which will require additional capital beyond Q3 2022. One interim analysis (based on number of primary events) is also planned at approximately 24 months after full enrollment.

EDSIVO™ (celiprolol) is an investigational product candidate which has not been approved by the U.S. Food and Drug Administration (FDA). There is no guarantee that this product candidate will receive regulatory authority approval or become commercially available for any indications in the U.S.

About EDSIVO™ (celiprolol)

EDSIVO™ (celiprolol) is a new chemical entity (NCE) currently in Phase 3 development for the treatment of COL3A1-positive VEDS patients to potentially reduce the risk of arterial and other hollow organ clinical events. In October 2010, data was published in the Lancet from the BBEST trial designed to assess the preventative effect of celiprolol for major cardiovascular events in patients with VEDS via a multicenter, prospective, randomized, open trial with blinded evaluation of clinical events. In addition, data from long-term observational studies of patients treated with celiprolol in France and Sweden were published in the Journal of the American College of Cardiology (JACC) in April 20193 and in the European Journal of Vascular and Endovascular Surgery (EJVES) in November 20204, respectively. Data from these and other publications can be found at Acer’s original NDA was submitted based on data obtained from the BBEST trial and accepted for filing in October 2018 with priority review. Following FDA review, Acer received a Complete Response Letter (CRL) in June 2019 stating that it will be necessary to conduct an adequate and well-controlled trial to determine whether EDSIVO™ reduces the risk of clinical events in patients with VEDS. In April 2022, FDA granted celiprolol Breakthrough Therapy designation in the U.S. for the treatment of patients with COL3A1-positive VEDS. In May 2022, Acer reached agreement with FDA under an SPA for its Pivotal Phase 3 clinical trial of EDSIVO™ (celiprolol) for the treatment of patients with COL3A1-positive VEDS, and patient screening was initiated in June 2022. Celiprolol received FDA Orphan Drug Designation for the treatment of VEDS in 2015.

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. Acer’s pipeline includes four investigational programs: ACER-001 (sodium phenylbutyrate) for treatment of various inborn errors of metabolism, including urea cycle disorders (UCDs) and Maple Syrup Urine Disease (MSUD); ACER-801 (osanetant) for treatment of induced Vasomotor Symptoms (iVMS); 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