The results of Biogen’s new experimental drug for Alzheimer’s disease has provided the best evidence so far that the memory-robbing condition is caused by a protein in the brain that, if stopped from acting erratically, could lead to an effective treatment for the disease. While German psychiatrist Alois Alzheimer was the first to connect dementia to an abnormal protein deposit in the brain, it has taken until now for scientists to understand where the protein, known as beta amyloid, was made and to see it as a potential target in treating Alzheimer’s disease.
Clinical Trials of the New Drug
Prior to the testing of this new drug, no clinical trials had been run that had previously reduced beta amyloid in subjects’ brains while also slowing the deterioration in their cognition. Now, the findings on BIIB037, Biogen’s medication, show that it’s possible. In an early stage trial, 166 participants who took BIIB037 showed reduced beta amyloid in the brain and reduced cognitive decline.
Furthermore, with higher doses and longer treatment, patients in the trial saw even more improvements. Based on the Clinical Dementia Rating, BIIB037 showed a 71% reduction in cognitive decline among patients who took the highest dose, compared with those on placebo. The results of this trial show that “it’s a major advance in confirming amyloid beta is the right target.”
Other Alzheimer’s Drug Testing
Researchers have said that BIIB037 is “a chance that this could be the first registered disease-modifying drug for Alzheimer’s disease.” As Biogen prepares the drug for late=stage trials of BIIB037 later this year, other drug companies have tried and failed to have success with their own Alzheimer’s medications.
Two medications, solanezumab, from Eli Lilly & Co., and bapineuzumab, developed by Pfizer Inc., Johnson & Johnson and Elan Corp., both failed to show a significant effect on the disease in their own trials. Eli Lilly is now retesting their drug in earlier-stage Alzheimer’s patients, while bapineuzumab has been scrapped by their group. In addition, Roche Holding AG is sponsoring a drug trial of its own amyloid-targeting drug in Alzheimer’s patients with mild dementia. However, in December it abandoned their drug study of people with early stages of the disease because of poor results.
Possible Side Effects of the Drug
Although BIIB037 shows some serious promise in terms of fighting Alzheimer’s disease, there is also the potential for serious side effects. Most concerning is brain swelling known as amyloid-related imaging abnormalities, or ARIA. “Among patients carrying the ApoE4 gene, which is strongly linked with Alzheimer’s, 55% of patients on the highest dose reported ARIA. That resulted in 35% of the ApoE4 carriers on the highest dose discontinuing treatment.” Finally, 22% of patients in the trial who took the drug had headaches, versus only five percent on a placebo.
Researchers have also admitted that even with the promising results of Biogen’s drug, Alzheimer’s disease should still be approached from multiple angles. “It’s not an either/or,” said the director of global science initiatives at the Alzheimer’s Association. “There needs to be as many of those as possible so we can have a fuller understanding of Alzheimer’s.”