CNS therapeutics company Accera's AC-1204 has failed to demonstrate a positive outcome in the Phase III trial for the treatment of patients with mild-to-moderate Alzheimer's disease.

AC-1204 is a small-molecule drug compound designed to leverage the physiological ketone system in order to address the deficient glucose metabolism in Alzheimer's.

The ketones are thought to have a potential to restore and improve neuronal metabolism, resulting in better cognition and function.

The trial results indicated that the drug did not show a statistically significant difference at week 26 when compared with placebo, as measured by the Alzheimer's disease assessment scale-cognitive subscale test (ADAS-Cog).

"The formulation of the drug was changed between the Phase II and Phase III studies."

The double-blind, randomised, placebo-controlled, parallel-group Phase III (NOURISH AD) trial evaluated the effects of daily administration of AC-1204 in the subjects for 26 weeks.

Accera research and development vice-president Samuel Henderson said: "The formulation of the drug was changed between the Phase II and Phase III studies.

"Unfortunately, this change in formulation had the unintended consequence of lowering drug levels in patients. We are confident that our newly developed formulation will provide increased exposure and allow a more conclusive test of drug efficacy."

The primary and key secondary endpoints of the trial are the measure of AC-1204 effects on memory, cognition and global function.

While the drug was found to be safe with high levels of tolerability, a detailed pharmacokinetic analysis showed that the modified formulation used in the study led to a decrease in drug plasma levels when compared to prior formulations.