Clinical trials of a once-promising Alzheimer’s disease drug from Merck & Co. were halted after an outside panel of medical specialists concluded that there was “virtually no chance of finding a positive clinical effect.” This comes just three months after a treatment from Eli Lilly & Co. failed in a trial, raising questions about when an effective treatment will be found.
Alzheimer’s affects 44 million people worldwide, and while drugs do exist that lessen the disease’s symptoms, none have been produced that are able to stop its progression. More than a dozen companies are currently testing drugs in late-stage trials, including Cambridge-based Biogen Inc., Merck & Co. and Eli Lilly & Co.
Many of the drugs currently being tested target amyloid plaque in the brain, which is believed to be the cause of the degenerative disease.
The failure of Merck’s drug focuses attention on Biogen Inc.’s experimental medication, which is showing promising results in lowering amyloid plaque levels in patients who continued to take it after the initial round of testing.
Biogen is now focusing its efforts on enrolling patients in a more advanced trial which will involve up to 3,000 people from over 20 countries in an effort to see how different testing methods impact the effectiveness of their drug.
Multiple factors can contribute to a medication failing in trials, such as underestimating how advanced the disease is in patients before the drug is tested. For those who already have plaque buildup, the drug likely would not have any tangible effect, as it is a preventative medicine.
James Hendrix, director of global science initiatives at the Alzheimer’s Association, said “you need to go in at the very earliest stage of disease to show the kind of improvement we are hoping for.”
The nature of Alzheimer’s makes it incredibly difficult to cure. Scientists do not have definitive proof of the exact cause of the degenerative disease, thus making it hard for researchers to develop drugs that will be effective in stopping its course.
With so many trials still ongoing, the effort to find a cure is far from over and researchers will continue to learn more about Alzheimer’s through these tests.
Top photo by Jamie, CC BY 2.0
Lauren Leising is a freelance writer based in Athens, Georgia.