Posted 29 November 2016
By Michael Mezher
The European Medicines Agency (EMA) on Tuesday published an analysis highlighting the complexity of developing treatments for central nervous system (CNS) disorders, such as Alzheimer's disease, epilepsy and schizophrenia.
"Research into medicines for CNS is complex, with a higher rate of failure during the clinical development of these products compared to other fields of medicine," EMA says.
To conduct its analysis, EMA says its staff members reviewed a total of 103 applications submitted between 1995 and 2014 for various CNS disorders, looking specifically at the major objections raised by the Committee for Medicinal Products for Human Use (CHMP) during the review process for neurological and psychiatric drugs.
Although the majority of the drugs looked at for the analysis went on to receive a positive CHMP opinion, nearly a third (29) were rejected or withdrawn before a decision was made.
According to the agency, more than a third of the applications had issues related to clinical efficacy and safety in late stage studies.
EMA also found that nearly all of the programs that had issues in early phases of development went on to have issues with the results of their confirmatory studies, whereas only 55% of applications that did not have issues early on had such issues later on.
As such, EMA says that companies should pay careful attention to the design of early-stage clinical trials to boost their program's chances of success.
Figre 1. Applications With Identified Problems
The analysis also found that different variables had a greater impact on psychiatric drugs compared to neurological drugs. For instance, the analysis found the selection of study population for Phase III studies to be the most important variable for psychiatric drugs, whereas the success or failure of the primary efficacy endpoint was the most important factor for neurological drugs.
Figure 2. Importance of Variables on Application Outcome