Posiphen, a drug candidate designed and developed by researchers in the NIA’s Intramural Research Program, has been shown in three small, early studies to be well-tolerated and to reduce the generation of amyloid and tau protein—the hallmarks of Alzheimer’s disease—in older people at risk for developing the disorder. The series of dosing, tolerability, and “proof of mechanism” studies was conducted by an international group of investigators testing a pill form of the drug Posiphen during trials of seven to ten days in healthy volunteers and those with mild cognitive impairment (MCI), a condition that often progresses to Alzheimer’s. The report of the research appeared online July 11, 2012 in the Journal of Neurology, Neurosurgery & Psychiatry.
Posiphen was determined to readily enter the brain and in cerebrospinal fluid tests, scientists found that the drug lowered levels of amyloid, tau, and inflammation—all key targets in the effort to find therapies for Alzheimer’s. Researchers believe the drug may work by inhibiting the production of neurotoxic products that derive from amyloid precursor protein, or APP, and result in the accumulation of abnormal clumps of amyloid. While the finding is preliminary, it does provide key data to move the drug forward for further human testing.
Reference: Maccecchini, M., et al. Posiphen as a candidate drug to lower CSF amyloid precursor protein, amyloid-b peptide and s levels: target engagement, tolerability and pharmacokinetics in humans. Journal of Neurology, Neurosurgery & Psychiatry.  Doi: 10.1136/jnnp-2012-302589.