The design and evaluation of pharmacological clinical trials in Alzheimer’s disease. New tendencies
Introduction. We analyze current problems with clinical trials in Alzheimer’s disease (AD) by reviewing the literature of the past five years. We briefly mention the guidelines of the drug evaluation agencies, scientific institutions and industry. We comment on the difficulties in the evaluation of clinical trials in patients with AD regarding cognitive, functional, behavioral and overall aspects together with the quality of life of both patient and carer, and finally the increasing importance of cost-benefit assessment of drugs for AD. Patients and methods. The design and carrying out of clinical trials vary considerably depending on the drug involved. It is relatively simple with drugs causing marked symptomatic improvement in patients with AD, but complex and costly (many patients and a long follow-up) when dealing with neuroprotector effects. This is much more difficult (no double blind trial has yet been done) to try to assess a possible effect of prevention of AD. Conclusions. We consider methodological aspects of clinical trials such as current difficulties in the use of placebos. It is concluded that in spite of little progress in the pharmacological treatment of AD, this will probably improve with use of current methodology and considering the importance of this disorder. It is to be expected that clinical trials will be carried out to prevent the disorder in patients with a biological risk of AD
Pacientes y métodos El diseño y la implementación de un ensayo clínico difiere de forma muy importante según el tipo de fármaco que se va a emplear. Es relativamente sencillo si el medicamento determina una mejoría sintomática del paciente con EA, pero complejo y costoso (series amplias, largo tiempo de evolución) si se trata de evaluar un efecto neuroprotector, y mucho más problemático (aún no se ha efectuado ninguno con metodología doblemente ciega) si se intenta comprobar un posible efecto preventivo del desarrollo de EA.
Conclusiones Se comentan aspectos metodológicos de los ensayos clínicos como la dificultad de utilizar placebos en el momento actual. Se concluye afirmando que pese a los reducidos logros actuales en el tratamiento farmacológico de la EA, parece lógico pensar en un futuro más halagüeño dado el importante desarrollo metodológico actual y la importancia de esta enfermedad. Es de esperar que se inicien ensayos clínicos en los que se pretenda prevenir esta enfermedad en pacientes con riesgo biológico de EA
