Acer Therapeutics Announces Full Enrollment of Phase 2a Trial for Treatment of Moderate-to- Severe Vasomotor Symptoms Associated With Menopause

Acer Therapeutics Inc. recently 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).

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. 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. ACER-801 is orally bioavailable and readily crosses the blood-brain barrier. Acer believes 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.

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 US, 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.