Acer Therapeutics Inc., a pharmaceutical company, focuses on the acquisition, development, and commercialization of therapies for serious rare and life-threatening diseases. The company's pipeline includes four clinical-stage candidates comprising EDSIVO for the treatment of vascular Ehlers-Danlos Syndrome in patients with a confirmed type III collagen mutation; ACER-801 for the treatment of induced Vasomotor Symptoms, post-traumatic stress disorder, and prostate cancer; and OLPRUVA, a formulation of sodium phenylbutyrate for the treatment of various inborn errors of metabolism, including urea cycle disorders and maple syrup urine disease. It has a license agreement with Sanofi to acquire worldwide rights to Osanetant, a clinical-stage, selective, and non-peptide tachykinin NK3 receptor antagonist; an option agreement with Relief for the development, regulatory approval, and commercialization of OLPRUVA; and an agreement with Emory University to acquire the worldwide intellectual property rights to a family of patents and patent applications related to the use of neurokinin receptor antagonists in managing conditioned fear and treating anxiety disorders, including post-traumatic stress disorder. The company was incorporated in 1991 and is headquartered in Newton, Massachusetts. As of November 17, 2023, Acer Therapeutics Inc. operates as a subsidiary of Zevra Therapeutics, Inc.