A new drug meant to slow the cognitive decline of dementia patients fell short of its expected goal. Although scientists didn't find the results they were expecting, the research didn't prove entirely fruitless.
The new study, conducted by researchers at Brown University, examined the high-profile failure of a promising medication called bapineuzumab, which was supposed to delay the degeneration in the brains of dementia patients. The findings were published on Jan. 23 in the New England Journal of Medicine. Stephen Salloway, a professor of neurology and psychiatry and lead author of the study, explained in a press release that the antibody failed to produce any improvement whatsoever compared to a placebo.
"We don't have the luxury of time," Salloway elaborated to the source. "There is an urgency that doesn't allow us to wait."
The trials started in 2012, when the team of researchers administered two randomized, controlled and double-blind tests. The first trial involved the drug in 1,121 carriers of the apolipoprotein E (APOE), the gene that is associated with a higher risk of Alzheimer's disease. In the second test, 1,331 participants between 50 and 88 years old were analyzed, taking MRI scans. Cognitive test scores indicated a high probability of Alzheimer's.
Subjects received the drug intravenously every 13 weeks for 78 weeks. After each session they took cognitive tests. Salloway also conducted brains scans and fluid samples for various biomarkers, including levels of amyloid beta plaques and tau protein linked to the degeneration of brain cells.
Bapineuzumab, dubbed "bapi," is an antibody drug that binds to and prevent these amyloid beta proteins from forming harmful plaques in the brains of Alzheimer's patients. However, when the scientists calculated the sores of the cognitive tests – Disability Assessment for Dementia (DAD), it became clear that bapi did nothing substantial either for APOE carriers or non-carriers. DAD scores worsened on average during the trial, with bapi showing no improvement over the placebo.
"It is very disappointing, especially to the terrific and dedicated patients and their families," Salloway told the source. "So much effort went into this trial. Alzheimer's is a difficult and complex disease, and we are moving forward."
The silver lining
Despite bapi's shortcomings, Salloway and colleagues learned several lessons for the next round of their studies. First, it's important to test drugs only with people who are building up the amyloid beta plaques, which the drugs address. Next, they should give drugs in doses that safely induce greater amyloid decrease, and combine disease-modifying treatments that might be complementary. Another key may be to test these treatments at an earlier stage when amyloid plaques are rising but before symptoms of cognitive decline have set in.
Salloway also pointed out that drug combinations rather than single drugs have proven to be the solution for some forms of cancer as well as other converting previously incurable diseases, such as HIV, into manageable long-term conditions.
Hoping for a breakthrough
While the researchers will bear in mind the unexpected fruits of their study, they couldn't help but acknowledge the drug's astounding failure.
"The biggest disappointment from this trial, was that if we had shown benefit with a drug like bapi, it would give people hope that Alzheimer's is a treatable disease, that we can slow it down," Salloway went on to the source.
Currently, dementia affects 6.8 million people in the U.S., according to the National Institute of Neurological Disorders and Stroke.
"For the level of suffering with this disease and for our economy, we have to break down some barriers and come up with innovative approaches," the neurology professor concluded.