Scientists discover why animal studies may lead to ineffective ALS drugs

A five-year study of more than 70 drugs, many with reported survival benefit in a mouse model of the inherited form of amyotrophic lateral sclerosis - or Lou Gehrig's disease, concluded that the apparent positive effects were largely due to previously-unrecognized variables in the study design, scientists have reported. The assessment included riluzole (Sanofi-Aventis' Rilutek), the only drug approved by the US Food and Drug Administration for ALS treatment.

The study was undertaken to evaluate possible ALS treatments, and to put money and resources behind the most promising ones. Despite the findings, the investigators said the study establishes guidelines for evaluating preclinical mouse studies in ALS, and provides a starting point for standardizing the use of this animal model of ALS.

"Researchers have been puzzled as to why animal results have failed to replicate in the clinic," said Sea Scott, the principal investigator and president of the Cambridge-based ALS Therapy Development Institute, which conducted the work. "It appears this animal model is subject to greater variability than many investigators realized. The exciting part of this study is that one can now identify and substantially eliminate the biological variability to fully exploit the value of this animal model for identifying effective treatments," he noted.