CX717 is an ampakine compound created by Dr. Gary Lynch at UCI in 1993 and further developed by Cortex Pharmaceuticals, an Irvine company created to explore possible applications. It affects the neurotransmitter glutamate, with early trials showing the drug improves cognitive functioning and memory.
Also, in 2005, the United States Department of Defense funded a study to look into CX717 and the physiological effects of sleepiness. The study found that rhesus monkeys performed faster and better after receiving the drug, and it counteracted the effects of sleep deprivation.
April 18 2007 Cortex Pharmaceuticals submitted two large data packages to the FDA regarding CX717. One data set went to the FDA's Division of Neurology Drug Products for the treatment of Alzheimer's disease, while the other went to the Division of Psychiatry Products where the company intends to file a second CX717 IND for the treatment of ADHD. The submitted data package provides clear evidence that the specific histopathological changes seen in animal toxicology studies, which previously caused the FDA to put CX717 on clinical hold, is a postmortem fixation artifact and is not found in the tissue of the animal when it is still living.
Roger G. Stoll, Ph.D., Chief Executive Officer of Cortex, stated,
“When CX717 was removed from clinical hold on October 6, 2006 by the Neurology Division a dose was permitted for continuing a study in patients with Alzheimer's disease, but that dose was too low to permit the assessment of the drug in patients with ADHD. Further information was needed to better understand the cause of the histopathological changes. We now have a substantial data base which clearly documents the fact that the histological changes of concern occur postmortem when the fixative solution is used to prepare the slides of the tissue specimens.”
In early March 2006 Cortex reported in a small pilot Phase II study, that CX717 had demonstrated positive clinical and statistical results on the primary endpoint, the ADHD rating scale and the sub-scales related to attention and hyperactivity which are used for the approval of all currently available ADHD treatments. Consistent with all previous studies involving over 220 patients and healthy adults, this study demonstrated that CX717 was safe, well tolerated, and produced no increase in heart rate, blood pressure or other cardiovascular side effects. Cortex intends to cooperate fully with the FDA and the Company must now wait to hear from the agency regarding their willingness to approve higher dose levels for studying CX717 in adults with ADHD, and the Company’s subsequent desire to proceed with a larger Phase IIb study for this indication.
Other AMPAkine drugs from Cortex Pharmaceuticals such as CX614 have already been researched for use in treating Alzheimer's disease and ADHD. These drugs were reasonably effective at reducing the symptoms of Alzheimer's and it is hoped that they will also slow the progression of the disease. CX717 is a newer drug in the same series. The chemical structure of CX717 has not yet been revealed by Cortex Pharmaceuticals, but is presumably similar to earlier compounds in the series as shown below. It is very unusual for research on a compound to be released in scientific journals without disclosing exactly what the compound consists of, but this information is likely to have been kept confidential for reasons of intellectual property, and also because the research on CX717 was partially funded by DARPA, the United States Defense Advanced Research Projects Agency.
- Bast T, da Silva BM, Morris RG. Distinct contributions of hippocampal NMDA and AMPA receptors to encoding and retrieval of one-trial place memory. J Neurosci. 2005 Jun 22;25(25):5845-56.
- Effects of the potent ampakine CX614 on hippocampal and recombinant AMPA receptors: interactions with cyclothiazide and GYKI 52466
- Facilitation of Task Performance and Removal of the Effects of Sleep Deprivation by an Ampakine (CX717) in Nonhuman Primates
-  Cortex Pharmaceuticals press release