Analyses of natural courses of Japanese patients with Alzheimer's disease using placebo data from placebo-controlled, randomized clinical trials: Japanese Study on the Estimation of Clinical course of Alzheimer's disease

Introduction

Symptomatic anti-Alzheimer's disease (AD) drugs have been commonly used for the treatment of AD. Knowing the natural courses of patients with AD on placebo is highly relevant for clinicians to understand their efficacy and for investigators to design clinical studies.

Methods

The data on rating scales for dementia such as Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog) and Severe Impairment Battery were extracted from eight previous Japanese Phase II and III studies. Natural courses of Japanese AD patients in placebo groups were evaluated and statistically analyzed in a pooled and retrospective fashion.

Results

Decreases in ADAS-cog and Severe Impairment Battery was larger at week 22 or 24 than at week 12. Scores of ADAS-cog appeared to deteriorate faster in moderate AD than in mild AD.

Discussion

The present data will provide clinicians following up patients with AD with helpful information on how to manage AD patients and investigators with instruction for clinical study design.

Cognitive Efficacy (SIB) of 13.3 Versus 4.6 mg/24 h Rivastigmine Patch in Severe Alzheimer's Disease

Severe Impairment Battery (SIB) data from the 24-week, randomized, double-blind ACTivities of daily living and cognitION (ACTION) study suggest that patients with severe Alzheimer's disease (AD) benefit from treatment with 13.3 versus 4.6 mg/24 h rivastigmine patch. The objective of this retrospective analysis was to further examine the cognitive efficacy of 13.3 versus 4.6 mg/24 h rivastigmine patch on individual SIB items, and SIB domains derived using factor analysis of these items. Change from baseline at Week 24 on 9 new factor-defined domains and individual items was calculated and compared using effect sizes (Cohen's d). Numerically less decline was observed with 13.3 versus 4.6 mg/24 h patch on all domains and the majority of individual items. Largest least squares mean treatment differences were observed on "visuospatial reasoning," "object naming," "recognition," "design copying," "social agency," "ideational praxis," and "comprehension" domains. These findings suggest 13.3 mg/24 h rivastigmine patch demonstrates broad cognitive efficacy across a range of SIB items and domains in patients with severe AD.

Diagnosis and management of Alzheimer's disease: past, present and future ethical issues

There is great interest in the ethical issues associated with Alzheimer's disease (AD) and related dementias given the prevalence of AD and the evolving neuroscience landscape in matters of diagnoses and therapeutics. Much of the ethics discussion arises in the tension between the principle of not doing harm (principle of non-maleficence) in this vulnerable population and the development of effective treatments (principle of beneficence). Autonomy and capacity issues are also numerous, wide-ranging, and concern (1) day to day affairs such as driving safely and spending money wisely, (2) life-time events such as designating a legal representative in case of incapacity, making a will, (3) consenting to treatment and diagnostic procedures, (4) participating in research. The latter issue is particularly thorny and illustrates well the complexity of tackling concerns related to capacity. The impetus to protect AD patients has partly led to ethics regulation and policies making research on inapt patients more difficult because of stringent requirements for signed informed consent or for showing the value of the research to this specific patient population. New issues are arising that relate to earlier diagnosis using biomarkers and (possibly soon) the use of drugs that modify disease progression. We here summarize and discuss the different ethical issues associated with AD from a historical perspective, with emphasis on diagnostic and treatments issues.