Tetra Discovery Partners LLC, of Grand Rapids, Mich., said it completed its initial phase I single ascending-dose study of BPN14770, its treatment aimed at improving memory and slowing the progression of Alzheimer's disease, in 32 healthy volunteers. A second phase I trial is set to start in June to test multiple ascending doses of BPN14770, which is designed to work through the PKA-CREB pathway to enhance synaptic function of the brain neurons involved in memory and cognition.