22 Sep 2005

The New York-based biopharmaceutical company Axonyx announced Tuesday that its experimental acetyl cholinesterase inhibitor drug Phenserine was ineffective in two curtailed phase 3 trials. In preclinical studies, the drug had appeared not only to inhibit the enzyme acetyl cholinesterase, as do most other AD drugs, but also to reduce production of the Aβ peptide. However, the clinic doused resulting hopes, as is often the case with AD.

Following disappointing results of a first phase 3 trial earlier this year, the company decided to end enrollment of two ongoing, multicenter, international phase 3 trials. Axonyx cut short the dosing period from 26 to 12 weeks and pooled analysis of the two remaining patient groups totaling 225 cases, down from the planned 900. Neither of two used Phenserine doses showed a significant benefit over placebo on the chosen primary endpoint, that is, improvement on the widely used ADAScog and CIBIC+ scales.

In its press release, Axonyx stated that the company is still evaluating the Phenserine program. (For more details, see Axonyx website and click on “September 20, 2005.")—Gabrielle Strobel.