“This is a very important phase,” said Norman, who holds a doctorate in pharmacology. “These studies are done in healthy volunteers, not in patient populations, and just in a limited number of people. Most drugs are only in the body for a few hours, and that’s why we need to take drugs like aspirin multiple times a day. This one is different. These antibodies are expected to have a half-life — that’s the time it takes for half of it to disappear — of maybe three weeks instead of a few hours.
“People will be exposed for quite a long time, three weeks after one injection of the antibody,” said Norman.
Catalent Pharma Solutions is manufacturing the antibody under contract with UC.
Co-investigators in this study are Drs. Thomas Geracioti and Erik Nelson, professor and associate professor, respectively, in UC’s Department of Psychiatry and Behavioral Neuroscience. While the clinical trials will move forward, there is still ongoing research about the antibody that the federal FDA is requiring, said Norman. His lab is still trying to find a “maximum tolerable dose” of the antibody in animal models to guide proposed human clinical trials.
The FDA wants researchers to find a level of the antibody that would be harmful in humans by mimicking the effects in animal models. Establishing that level determines the appropriate dosage when the antibody is given as a therapy in humans. Three of four dosing levels of the antibody Norman has proposed for his clinical trial have FDA approval. Use of the fourth dosing level is pending.