Elan (ELN) and Wyeth (WYE) are using a new and unproven endpoint to measure the memory and mental status of patients in phase III trials of their experimental Alzheimer's drug bapineuzumab, say sources familiar with the studies' protocols.
By creating their own test to measure bapineuzumab's efficacy, Elan and Wyeth are seeking an alternative to the so-called ADAS-cog, despite that test's imprimatur as the gold standard measure of cognitive function. The ADAS-cog has been used as the basis for approval for all Alzheimer's disease drugs to date.
Elan has devised a new clinical endpoint, which it calls the Neuropsychological Test Battery, or NTB. The Irish drugmaker has used the NTB in previous studies of its Alzheimer's drugs to demonstrate improvements in the mental status of patients when similar measurements using ADAS-cog showed no benefit.
This is the first time, however, that Elan and partner Wyeth will attempt to convince regulatory authorities in the U.S. and Europe that the NTB should be considered as the basis to approve a new Alzheimer's drug.The companies are pushing the test even though the NTB has not yet been independently validated by anyone outside the two companies, nor has it ever been used as a primary endpoint in any pivotal trial for Alzheimer's. The ADAS-cog test, by comparison, is the most widely recognized and utilized measure of cognition in Alzheimer's drug trials. All four Alzheimer's drugs currently on the market used the ADAS-cog test as the endpoint of their phase III trials. As well, the only other two drug companies with experimental Alzheimer's drugs in phase III studies right now -- Myriad Genetics (MYGN - Get Report) and Medivation (MDVN - Get Report) -- are using the measure as their primary endpoint in their respective studies. Dr. Peter Davies, an Alzheimer's researcher at New York's Albert Einstein College of Medicine, questions why any company would seek to develop an alternative cognitive test when the standard and well-understood ADAS-cog test has proven time and time again to be entirely adequate. "What we need are better Alzheimer's disease drugs, not better tests," says Davies. "If a drug cannot show improvement in cognitive function using the ADAS-cog test, then the drug is not worth bothering with."