Treatment effect of memantine on survival in dementia with Lewy bodies and Parkinson's disease with dementia: A prospective study

Abstract

Objective: To investigate the effect on survival of treatment with memantine in patients with dementia with Lewy bodies (DLB) and Parkinson's disease with dementia (PDD). Methods: 75 patients with DLB and PDD were included in a prospective double-blinded randomised placebo-controlled trial (RCT) of memantine, of whom long-term follow-up was available for 42. Treatment response was recorded 24 weeks from baseline and measured by Clinical Global Impression of Change (CGIC). The participants were grouped as responders (CGIC 1-3) or non-responders (CGIC 4-7). The 24-week RCT was followed by open-label treatment and survival was recorded at 36 months. Results: After 36-month follow-up, patients in the memantine group had a longer length of survival compared with patients in the placebo group (log rank x2=4.02, p=0.045). Within the active treatment group, survival analysis 36 months from baseline showed that the memantine responders, based on CGIC, had higher rates of survival compared with the non-responders (log rank x2=6.595, p=0.010). Similar results were not seen in the placebo group. Conclusions: Early treatment with memantine and a positive clinical response to memantine predicted longer survival in patients with DLB and PDD. This suggests a possible disease-modifying effect and also has implications for health economic analysis. However, owing to the small study sample, our results should merely be considered as generating a hypothesis which needs to be evaluated in larger studies. Trial registration number: ISRCTN89624516.