FDA Approves
Memantine (Namenda) for Alzheimer's Disease
Oct. 17, 2003 - The Food and Drug Administration
(FDA) today approved memantine (NAMENDA), for treatment of moderate to
severe Alzheimer’s Disease. This is the first drug approved for the
treatment of patients with this severity of disease. Previous
treatments for Alzheimer’s Disease have been studied in less severely
affected (mild to moderate) patients. Memantine’s mechanism of action
is different from that of the drugs currently available for treating
this disease.
Alzheimer’s Disease, which affects about 4.5
million Americans, is a degenerative condition affecting memory,
judgment and the ability to reason. The new drug an -- N-methyl-D-asparate
(NMDA) antagonist -- is thought to work by blocking the action of the
chemical glutamate.
Although memantine helps treat the symptoms of
Alzheimer’s Disease in some patients, there is no evidence that it
modifies the underlying pathology of the disease.
FDA Commissioner Mark McClellan, M.D., Ph.D.
said, "The approval of memantine is good news for Alzheimers’ Disease
patients. This is the first drug shown to have an effect on the
symptoms of moderate to severe Alzheimer’s Disease, and shows a low
incidence of minor side effects."
The first two double-blind studies, each of about
six months duration, were conducted in the United States, and involved
about 250 and about 400 patients, respectively. The larger study was
carried out in patients already taking donepezil, a drug already
approved for the treatment of Alzheimer’s Disease. Both studies showed
that patients on memantine experienced less deterioration in their
symptoms compared to patients treated with placebo during the study.
The third study, conducted in nursing homes in Latvia, was a 12-week
double blind study in 166 patients with severe Alzheimer’s Disease and
also showed a statistically significant advantage of memantine over
placebo.
The studies utilized a variety of measures to
evaluate the effectiveness of memantine. For the two studies conducted
in the United States, the measures included the Severe Impairment
Battery (SIB) to assess attention, orientation, language, memory, and
social interactions, and the modified Alzheimer’s Disease Cooperative
Study – Activities of Daily Living (ADCS-ADL) scale, which assessed
the ability of patients to eat, dress, bathe, travel, shop and perform
household chores.
The third study utilized the Behavioral Rating
Scale for Geriatric patients (BGP), which assessed day-to-day
functioning and the Clinical Global Impression of Change (CGI-C),
which assessed the overall condition of the patients.
The most frequently reported adverse events were
dizziness (seven percent), headache (six percent), and constipation
(six percent).
FDA’s Peripheral and Central Nervous System Drugs
Advisory Committee this past September unanimously agreed that
memantine is effective and safe for the treatment of moderate to
severe Alzheimer’s Disease. Memantine will be marketed under the trade
name Namenda by Forest Labs of Jersey City, N.J. |
