By Mary Welch

Merz + Co. said two European Phase III trials showed Memantine produced significant improvement in cognitive performance in patients with mild to moderate vascular dementia.

The company, based in Frankfurt, Germany, plans on filing a marketing application in Europe for moderate to severe dementia, which includes both Alzheimer¿s disease and vascular dementia, in September.

A separate Phase III study in the U.S. with patients with moderately severe to severe Alzheimer¿s disease was completed, and the results will be presented in July at the Seventh Alzheimer¿s annual meeting in Washington. Merz and its U.S. collaborator, Neurobiological Technologies Inc., of Richmond, Calif., are seeking a development and marketing partner before requesting FDA approval for Memantine as an Alzheimer¿s treatment in the U.S.

The U.S. study also showed significant and positive results with 252 enrolled patients. (See BioWorld Today, Feb. 23, 2000, p. 1.)

In the European trials a total of 900 patients were enrolled, 579 in the UK trial and 321 in France. Both trials were randomized, placebo-controlled, double-blind studies that lasted six months with open-label extensions.

¿The primary endpoints included the Alzheimer¿s Disease Assessment Scale-Cognitive Subscale (ADAS-cog), as well as other measurement tools,¿ said Hans-Joerg Moebius, vice president of research and development of the company¿s pharma division. ¿In both trials the Memantine patients showed significantly improved cognitive abilities compared to placebo. Some of those cognitive abilities are word recognition or recall and recognizing a person.¿

Not only did patients significantly improve their cognitive function as assessed by the ADAS-cog test, but also by the MMSE test, or the Mini Mental-State Examination, he said. The largest treatment benefit in ADAS-cog was observed in patients with more advanced disease.

The results of the trials were presented at the Sixth International Stockholm/Springfield Symposium on Advances in Alzheimer Therapy.

Memantine is an uncompetitive moderate-affinity N-methyl-D-aspartate receptor antagonist. The symptomatic effect might be explained by an improvement of the signal-to-noise ratio in the neuronal transmission of information, according to the company.

Currently there is no effective treatment for vascular dementia, which is the second leading dementia type. As people live longer, vascular dementia is becoming more prevalent. Although not a part of normal aging, it most often occurs in older people.

Memantine also is being investigated to treat pain associated with diabetic neuropathy and AIDS-related dementia by Merz¿s U.S. collaborator, Neurobiological Technologies.