An experimental and closely followed drug for Alzheimer’s disease has failed a key clinical study, dealing yet another blow to the prevailing theory on how to treat a neurodegenerative illness that affects millions of people.
The drug’s developer, Roche, along with Banner Alzheimer’s Institute, the Phoenix-based organization helping lead the study, announced the negative results Thursday. After years following a family believed to be genetically predisposed to the disease, researchers found no significant difference in cognition or the ability to store and retrieve new memories between participants who received the drug and those who got placebo.
The failure is an upset not only to Roche, which hopes to follow its rival Biogen in getting an Alzheimer’s therapy approved for market, but also to the wider Alzheimer’s research field. For years, a protein called beta amyloid has been at the center of efforts to treat the disease. But every drug designed to block this protein, including Biogen’s, has faced setbacks. Roche’s announcement may therefore add to concerns that this protein isn’t the best research target.
“We’re disappointed that the treatment did not demonstrate a statistically significant clinical benefit,” Eric Reiman, the executive director at Banner and one of the study’s leaders, said in a statement.
“This trial, the data, samples, and findings that we’ll share with the research community, and the related work that we and others are doing promise to further accelerate the evaluation and approval of future prevention therapies,” Reiman added.
Uniquely, this trial focused on an extended Colombian family whose genetic makeup puts them at a much higher risk of developing the disease. A total of 252 family members participated in the study, with two-thirds carrying a gene that, according to Banner, makes them “virtually certain” to develop early-onset Alzheimer’s — usually by their mid-40s.
The trial officially began in late 2013. Over the course of five to eight years, participants were given either a placebo or Roche’s drug, which is known as crenezumab and works by binding to and clearing early forms of the beta amyloid protein before it aggregates into sticky, toxic plaques.