The drug, verubecestat, was being tested in patients who showed only a glimmer of the symptoms that eventually rob them of memories and basic functions. It’s another setback in a long list of experimental treatments that have had little or no effect on the neurodegenerative disease.
Another trial of the drug in patients with more advanced disease was abandoned last February, but Merck had carried on with the earlier-stage group under the theory that by treating patents before their symptoms worsened, a drug might halt damage before it was too late.
“We are disappointed with this outcome, especially given the lack of treatment options,” Roger Perlmutter, president of Merck Research Laboratories, said in a statement announcing the trial’s end. The company said that a board of experts overseeing the tests decided that it “was unlikely that positive benefit/risk could be established if the trial continued.”
Merck hasn’t decided whether to end development of the drug entirely, or what its next steps for the compound will be, said Pam Eisele, a spokeswoman for the Kenilworth, New Jersey-based company. She said the company has several other potential Alzheimer’s drugs in early stages of development.
Merck shares were little changed in late trading Tuesday. Investors have mostly written off many drugmakers’ attempts to find cures for the disease after Eli Lilly & Co., Pfizer Inc. and many others have failed.
High Risk, Little Reward
“Because the risk of failure is high, we have not been willing to give these compounds the benefit of the doubt,” said Tim Anderson, an analyst with Sanford C. Bernstein & Co. “Neuroscience drug development is tricky, and Alzheimer’s disease is the trickiest of them all, it seems.”
Merck’s drug belongs to a category of compounds called BACE inhibitors. The BACE drugs and other experimental treatments were meant to stop or clear the buildup of a brain plaque called amyloid that researchers have theorized may be a cause of the disease. Attempts to clear the plaque or inhibit its formation have failed repeated trials, however, raising questions about whether drugmakers have the right target.
