Results showed that there was no statistical difference in the mean change on AD Assessment Scale- Cognitive (ADAS-Cog) scores, the primary endpoint, after 16 weeks treatment with Huperzine A 200 micrograms bid compared to placebo (p=0.81). However, data demonstrated that the higher dose tested, 400 micrograms bid, showed cognitive enhancement on the ADAS-Cog versus placebo. The maximum cognitive improvement was observed at week 11 of treatment (p=0.001). Over 16 weeks Huperzine A (400 micrograms bid) improved cognition compared to placebo (p=0.03) and there was a trend to cognitive improvement over placebo at week 16 (p=0.069). In this clinical trial, there was an unexpected improvement in cognition in the placebo group at week 16 versus baseline.
On other secondary endpoints, including clinical global impression of change (ADCS-CGIC) and the Neuropsychiatric Inventory (NPI) there was no statistical difference between placebo and either 200 or 400 micrograms bid after 4 months treatment. However, there was a trend to improvement on activities of daily living (ADCS-ADL) with 400 micrograms bid (p=0.077). Huperzine A was safe and well tolerated. Overall the incidence of adverse events during the study was similar between both doses of Huperzine A and placebo.
Following completion of the double-blind part of this clinical trial, subjects were invited to receive Huperzine A treatment in an open-label fashion for up to one year and 82% of subjects accepted this invitation.
Gary Shearman, president and CEO of Neuro-Hitech, said: “The main purpose of this Phase II clinical trial was to gather data to inform us on the appropriate design of the pivotal Phase III registration studies required for marketing approval of Huperzine A.”