Preventive approaches in the field of Alzheimer disease (AD) is important but these trials raise many questions. Which protective factor should be studied? What population should be studied? With which principal and secondary criteria? We present here the design of the ongoing GuidAge Study. In the past, several studies suggest that Ginkgo biloba could have a potential benefit effect on cognitive function. The aim of the GuidAge Study is to evaluate the efficacy of 240 mg/d of EGb 761 in the prevention of AD.
GuidAge is a 5-year double-blind randomized trial conducted in France by a private practice/hospital network of general practitioners and hospital practitioners specializing in memory disorders. This study enrolled elderly subjects with spontaneous memory complaint and the primary outcome is the incidence of AD during a 5 years follow-up period. A total of 2854 subjects were enrolled between March 2002 and September 2004. The age of the study population was 76.8 +/- 4.4 with mean MMSE at entry 27.8 +/- 1.7.
The GuidAge study is the largest study carried out in Europe on the prevention of AD. Final results should be available in 2010.
"Commercially sponsored AD therapeutic trials and most prevention trials are typically more expensive. It is difficult to source the costs of an AD prevention trial for industry as only one such trial has been sponsored: a Ginkgo biloba extract study in France involving about 2800 patients over 5 years (Vellas et al., 2006b). "
[Show abstract][Hide abstract] ABSTRACT: Most current Alzheimer's disease (AD) therapies in advanced phases of development target amyloid β-peptide (Aβ) production, aggregation, or accumulation. Translational models suggest that anti-Aβ therapies may be highly effective if tested as agents to prevent or delay development of the disease or as therapies for asymptomatic patients with very early signs of AD pathology. However, anti-Aβ therapeutics are currently being tested in symptomatic patients where they are likely to be much less effective or ineffective. The lack of alignment between human clinical studies and preclinical studies, together with predictions about optimal trial design based on our understanding of the initiating role of Aβ aggregates in AD, has created a treatment versus prevention dilemma. In this perspective, we discuss why it is imperative to resolve this dilemma and suggest ways for moving forward in the hopes of enhancing the development of truly effective AD therapeutics.
[Show abstract][Hide abstract] ABSTRACT: Prevention in Alzheimer's disease and other dementias (AD/dementia) is defined on the basis of clinical states and their expressed symptoms. Primary prevention refers to delaying the development of the full-blown state of clinically expressed disease in normal individuals. Current primary prevention research is driven by evidence of AD/dementia protective factors that have emerged from epidemiological studies. The first randomized controlled trials (RCTs) of primary AD/dementia prevention have been designed to test the efficacy and safety of NSAIDs, hormonal therapy, antihypertensive drugs and antioxidants. The experience of these trials has indicated safety concerns as a key issue and highlighted significant design challenges in this type of research. These trials have required large sample sizes and unsustainable costs. There should be consideration given in future trials to enriching study samples with risk factors to increase progression rates to AD/dementia. Innovative strategies will also be needed to recruit and retain subjects given the long follow-up periods, modest perceived benefit and the potential for the risk-benefit ratio to change during the trial. It is foreseeable that regulatory authorities will be presented with primary prevention RCTs for approval and labelling, and that criteria to evaluate such evidence still need to be developed.
The Canadian journal of neurological sciences. Le journal canadien des sciences neurologiques 04/2007; 34 Suppl 1(S1):S84-9. DOI:10.1017/S0317167100005631 · 1.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A new Ginkgo biloba extract P8A (TTL), 70% enriched with terpene trilactones, prevents A beta(1-42) induced inhibition of long-term potentiation in the CA1 region of mouse hippocampal slices. This neuroprotective effect is attributed in large part to ginkgolide J that completely replicates the effect of the extract. Ginkgolide J is also capable of inhibiting cell death of rodent hippocampal neurons caused by A beta(1-42). This beneficial and multi-faceted mode of action of the ginkgolide makes it a new and promising lead in designing therapies against Alzheimer's disease.
Neurobiology of aging 08/2007; 30(2):257-65. DOI:10.1016/j.neurobiolaging.2007.05.025 · 5.01 Impact Factor
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