Is Alzheimer's Disease Drug Development Broken? What Must Be Improved.

During the decade from 2002 to 2012, 99.6% of the 244 agents tested for efficacy in slowing the progression of Alzheimer's' disease (AD) failed to achieve their primary endpoints. At a CTAD symposium on November 14, 2013, in San Diego, USA, an international group of AD researchers met to discuss the evolution of trials over the past 10 years and proposed a number of changes intended to streamline and enhance the efficiency of clinical trials. Approximately 1,031 AD trials were conducted between 2000 and 2012. The number of patients per trial site tended to decrease over time necessitating a larger number of sites. The use of biomarkers for enrichment purposes, or as measures of target engagement or surrogate outcomes, results in higher screen failure and drop-out rates, adding to trial duration and/or costs. Present disease modifying AD trials ask for increasing logistical and technical requirements, necessitating the creation of highly specialized trial facilities and limiting the participation of smaller sites. Due to heavy administrative and regulatory task, only about 13% of the team's time is used for the essential recruitment. Proposals and perspectives: Strategies suggested to improve the efficiency of recruitment include establishing "ready to go cohorts" in advance of trials using biomarkers and clinical measures. Simplification and harmonization of administrative procedures, including harmonization of certification procedures, are urgently needed. Alternative approaches, such as using the Internet to screen volunteers for possible inclusion needs to be evaluated. The AD drug development enterprise from discovery through clinical trials requires re-examination and re-organization if new drugs are to be delivered to patients in a timely way.