By Alice Park
There hasn’t been much good news lately on the Alzheimer’s drug front, with a number of companies either abandoning their Alzheimer’s research efforts or stopping studies of experimental medications. Over the summer, Eli Lilly and AstraZeneca PLC terminated their development of an experimental treatment when studies failed to show improvement in people with early signs of cognitive impairment. In January, Pfizer closed its neurodegenerative disease research, and a month later, Merck stopped development of its Alzheimer’s drug candidate after disappointing results.
But at the annual meeting of the Alzheimer’s Association in Chicago, there was some encouraging news about an anti-amyloid drug being tested by Eisai, a Japanese company, and Biogen, based in Massachusetts. The compound, BAN2401, is an antibody designed to stick to amyloid, the protein that builds up in the brain and can lead to sticky plaques that compromise nerve cells. The study involved people with mild cognitive impairment (which can be the gateway to dementia and Alzheimer’s dementia) or mild Alzheimer’s dementia, and according to the latest results, people treated with the experimental therapy showed a decrease in amyloid in the brain after 18 months compared to people treated with placebo. The treated group also showed slower declines on cognitive test scores at the end of the study, although the study did not have enough people to make this change statistically significant.
The data was more encouraging than the 12-month results, which the companies released last December, in which they failed to find a meaningful difference in the people who were treated compared to the people who were not. But the longer time period showed some encouraging declines in the amount of amyloid in the brain, and some hopeful slowing of cognitive decline in the people receiving the drug.
Of nearly 900 people randomly assigned to receive one of several doses of BAN2401 or placebo, those receiving the highest dose, 10 mg/kg bi-weekly, showed anywhere from 30% to 47% slower decline in two different batteries of cognitive tests that assessed memory, word recall and other functions. And among those who got the drug, 81% converted from showing positive amyloid in brain scans at the beginning of the study to becoming negative for amyloid after 18 months. That’s promising, since researchers believe that amyloid is a key contributor to the deteriorating brain functions typical of dementia and Alzheimer’s.
The results should serve as a catalyst for hope after years of frustration. BAN2401 belongs to a group of drugs that could be the first to treat Alzheimer’s rather than simply address its symptoms, as current therapies do. By reducing the buildup of amyloid plaque in the brain, the drug could slow the progression of the disease, and, if introduced early enough, perhaps even help some people to avoid its most devastating symptoms of memory loss and cognitive decline.
More data needs to be collected on BAN2401 in coming years, as it moves into the next phase of human testing. Researchers said they will continue to analyze the data with specifics to when during the disease process the drug is started, as well as whether people were taking other treatments for Alzheimer’s symptoms.
The Alzheimer’s Association noted that BAN2401 is the second experimental drug to show effectiveness in reducing amyloid burden in the brain. The first was aducanumab, which is also being developed and tested by the same two companies in a more advanced phase 3 trial. Final results from that study are expected in 2020.
If both experimental drugs continue to show promise in reducing amyloid in the brain and, perhaps just as important, in slowing the decline of cognitive skills such as memory, the drugs could become important as a preemptive strike against Alzheimer’s. Experts may consider using the drugs even earlier in the disease; advances in ways to diagnose Alzheimer’s as early as possible, even before memory symptoms start to become obvious, could make earlier treatment possible too.