Pretreatment Cognitive Profile Likely to Benefit from Donepezil Treatment in Dementia with Lewy Bodies: Pooled Analyses of Two Randomized Controlled Trials

Background/Aims: Based on Mini-Mental State Examination (MMSE) subitem scores, in dementia with Lewy bodies (DLB), we aimed to delineate features of cognitive impairment, identify cognitive domains improved by donepezil, and define a pretreatment cognitive profile likely to benefit from donepezil. Methods: Pooled data were used from two randomized controlled trials of donepezil in DLB (n = 235). Baseline MMSE subitem scores were calculated for all patients. Mean changes in subitem scores at week 12 were compared between the placebo and the active group. Finally, the subgroup identification based on differential effect search (SIDES) method was applied. Results: Baseline subitem scores were relatively low for serial 7's, delayed recall, and copying. Significant improvement by donepezil was found for orientation, serial 7's, repetition, 3-step command, and copying. The subgroup with pretreatment scores of serial 7's = 1, 2, or 3, delayed recall ≥1, and copying = 0 were the best responders. MMSE change in subgroups increased as more of these three conditions were fulfilled. Conclusion: Cognitive domains characteristically impaired in DLB are particularly improved by donepezil. The number of fulfilled conditions for serial 7's = 1, 2, or 3, delayed recall ≥1, and copying = 0 (likely to benefit score) may predict the response to donepezil in DLB patients.