GRAND RAPIDS, Mich.--(BUSINESS WIRE)--Tetra Therapeutics today announced that it has entered into a definitive merger agreement for Shionogi & Co., Ltd. to acquire Tetra. With this acquisition, Shionogi will obtain global rights to Tetra?s entire portfolio of compounds for the treatment of brain disorders associated with cognitive and memory deficits, notably BPN14770, a selective inhibitor of phosphodiesterase-4D (PDE4D). The two companies entered into a collaboration and investment agreement in 2018 and earlier this year announced an expanded alliance to develop and commercialize BPN14770 for the treatment of Alzheimer?s disease (AD), Fragile X syndrome (FXS) and other indications. Currently, Tetra is conducting a Phase II study in FXS and recently completed a Phase II study in AD in the United States. ?With over a decade of research, development and investment, Tetra has demonstrated the unique ability of allosteric inhibitors of phosphodiesterase-4D (PDE4D) to deliver disease-modifying potential in central nervous system (CNS) disorders,? said Mark Gurney, Ph.D., Chairman and Chief Executive Officer of Tetra Therapeutics. ?Shionogi has been a valued partner for the last two and half years, and with the company?s development and commercialization expertise, we believe Shionogi is ideally positioned to bring the potential of our platform to patients and provide new treatment options within these areas of urgent medical need. This is a great outcome for our investors and stakeholders.? "We are excited to combine Tetra?s portfolio with our drug development capabilities to further advance BPN14770 in CNS disorders, including AD and FXS," said Dr. Isao Teshirogi, President and Chief Executive Officer, Shionogi & Co., Ltd. ?Tetra?s deep level of drug discovery know-how in the CNS area will help us to solve for the cognitive disorders our ageing population is facing, and we believe we are well-positioned to bring BPN14770 to patients in need." Under the terms of the merger agreement, Tetra will become a wholly owned subsidiary of Shionogi, and Shionogi will have global rights to BPN14770 and all Tetra compounds. Based on the achievement of certain predetermined regulatory and commercial milestones the total transaction value may be up to $500 million. About BPN14770 BPN14770 is a novel therapeutic agent that selectively inhibits phosphodiesterase-4D to enhance early and late stages of memory formation. This unique mechanism of action has the potential to improve cognitive and memory function in devastating CNS disorders, including FXS, AD and other dementias, learning/developmental disabilities and schizophrenia. Preclinical animal models show that BPN14770 has the potential to promote the maturation of connections between neurons, which is impaired in patients with FXS, and to protect connections between neurons which otherwise are lost in patients with AD. Tetra currently is completing an investigational Phase 2 study of BPN14770 in adults with FXS, an indication for which BPN14770 has received Orphan Drug Designation from the U.S. Food and Drug Administration (FDA). About Tetra Therapeutics Tetra Therapeutics is a clinical stage biotechnology company developing a portfolio of therapeutic products that will bring clarity of thought to people suffering from Fragile X syndrome, Alzheimer's disease, traumatic brain injury, and other brain disorders. Tetra uses structure-guided drug design to discover mechanistically novel, allosteric inhibitors of phosphodiesterase 4 (PDE4), an enzyme family that plays key roles in memory formation, learning, neuroinflammation, and traumatic brain injury. Tetra Therapeutics is headquartered in Grand Rapids, Michigan. For more information, please visit the company's website at?http://www.tetratherapeutics.com. About Shionogi & Co., Ltd. Shionogi & Co., Ltd. is a major research-driven pharmaceutical company dedicated to bringing benefits to patients based on its corporate philosophy of ?supplying the best possible medicine to protect the health and wellbeing of the patients we serve.? Shionogi?s research and development currently targets two therapeutic areas: infectious diseases, and pain/CNS disorders. For over 50 years, Shionogi has developed and commercialized innovative oral and parenteral anti-infectives. In addition, Shionogi is engaged in new research areas, such as obesity/geriatric metabolic diseases and oncology/immunology. Contributing to the health and QOL of patients around the world through development in these therapeutic areas is Shionogi?s primary goal. For more details, please visit?www.shionogi.co.jp/en/.