Acer Therapeutics Inc. 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 Second Quarter 2023.
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.