After a courtship of more than a year, Tetra Discovery Partners LLC and Shionogi & Co. Ltd. tied the knot to develop and commercialize BPN-14770, Tetra's phosphodiesterase 4D (PDE4D) allosteric inhibitor, for the treatment of fragile X syndrome (FXS), Alzheimer's disease (AD) and other indications marked by cognitive and memory deficits.