Background: Alzheimer disease (AD) causes progressive cognitive and functional decline over years. Although cholinesterase inhibitors have demonstrated efficacy in studies lasting 3 to 6 months, little is known about long-term therapy.
Objective: To report the long-term cognitive effects of galantamine hydrobromide given continuously for 36 months in AD patients.
Participants: Subjects were 194 US patients with mild to moderate AD who had been randomized to continuous galantamine therapy in either of 2 double-blind placebo-controlled trials. Subjects subsequently received open-label continuous galantamine therapy for up to 36 months.
Main outcome measures: Effects on cognition were analyzed as change from study enrollment baseline in scores on the Alzheimer's Disease Assessment Scale-11-item cognitive subscale. Cognitive decline in galantamine-treated subjects was compared with that in a clinically similar historical control sample of AD patients who had received placebo for 12 months and with the mathematically predicted decline of untreated patients over 36 months. The rate of cognitive decline of patients who completed the entire 36-month trial (n = 119) was compared with that of patients who withdrew for any reason during the long-term open-label extension (n = 75). An inverted responder analysis was also performed in 36-month completers.
Results: Patients treated continuously with galantamine for 36 months increased a mean +/- SE of 10.2 +/- 0.9 points on the Alzheimer's Disease Assessment Scale-11-item cognitive subscale-a substantially smaller cognitive decline (approximately 50%) than that predicted for untreated patients. Patients discontinuing galantamine therapy before 36 months had declined at a similar rate before discontinuation as those completing 36 months of treatment. Almost 80% of patients who received galantamine continuously for up to 36 months seemed to demonstrate cognitive benefits compared with those predicted for untreated patients.
Conclusions: Cognitive decline over 36 months of continuous galantamine treatment was substantially less than the predicted cognitive decline of untreated patients with mild to moderate dementia. Thus, the cognitive benefits of galantamine seemed to be sustained for at least 36 months. These findings suggest that galantamine slows the clinical progression of AD.