Evaluating Response to High-Dose 13.3mg/24h Rivastigmine Patch in Patients with Severe Alzheimer's Disease.

Abstract

To identify factors predicting improvement/stabilization on the Alzheimer's Disease Cooperative Study-Clinical Global Impression of Change (ADCS-CGIC) and investigate whether early treatment responses can predict long-term outcomes, during a trial of 13.3mg/24h versus 4.6mg/24h rivastigmine patch in patients with severe Alzheimer's disease (AD). Logistic regression was used to relate Week 24 ADCS-CGIC score to potential baseline predictors. Additional analyses based on receiver-operating characteristic curves were performed using Week 8/16 ADCS-CGIC scores to predict response (13.3mg/24h patch) at Week 24. ADCS-CGIC score of (1) 1-3="improvement," (2) 1-4="improvement or no change". "Treatment" (13.3mg/24h patch) and increased age were significant predictors of "improvement" (P=0.01 and P=0.003, respectively), and "treatment" (P=0.001), increased age (P=0.002), and prior AD treatment (P=0.03) for "improvement or no change". At Week 8 and 16, ADCS-CGIC scores of 4 and 5 were optimal thresholds in predicting "improvement," and "improvement or no change," respectively, at Week 24. A significant therapeutic effect of high-dose rivastigmine patch on ADCS-CGIC response was observed. The 13.3mg/24h patch was identified as a predictor of "improvement" or "improvement or no change". Patients with minimal worsening/improvement/no change after treatment initiation may be more likely to respond following long-term therapy.