Could Alzheimer’s Drug Extend Survival in LBD?

While symptoms of Lewy body dementia may be improved with treatment, no medications have been proven to lengthen the time someone lives with the disease. A small but encouraging new study suggests that memantine — a medication originally developed to treat dementia in Alzheimer’s disease — may lead to longer survival for individuals with dementia with Lewy bodies (DLB) or Parkinson’s disease dementia (PDD).

As reported in our September issue, memantine has already been shown to improve some LBD symptoms, including cognition and sleep for those with DLB and PDD. That study evaluated the effects of memantine on 75 people with DLB or PDD in a double-blinded, randomized trial. After 24 weeks of treatment, the participants who showed a positive response were identified as “responders” versus the “non-responders” who showed no improvement. The study continued as an open-label trial in which both the researchers and participants knew which treatment (memantine vs. placebo) was being administered.

Researcher Kajsa Stubendorff of Lund University and colleagues in Sweden, the UK and Norway, reviewed the results of this study and found that, after 36 months, people who were treated with memantine had a longer survival time than those who received a placebo. Additionally, of the group that received the memantine, “responders” had a higher survival rate than “non-responders”.

The authors hypothesized from these results that memantine may have a “disease-modifying” effect. However, they were very cautious to note the small number of patients (32) evaluated in this analysis. The authors concluded that a larger study focused on survival would need to be conducted to verify or disprove this intriguing hypothesis.

Longitudinal studies of promising new LBD treatments such as this are urgently needed and are a top LBD research strategy in the National Plan to Address Alzheimer’s Disease (NAPA). NAPA includes related dementias like LBD, vascular dementia and frontotemporal dementia. Longitudinal studies follow the same group of patients over time.

Funding for this study was provided by the Swedish Research Council and the Swedish Parkinson Foundation.

Recent reports indicate there is a shortage of both the short-and long-acting forms of memantine. For more information, visit the Food and Drug Administration or the American Society of Health-System Pharmacists websites.