Clinical Trials For Two Alzheimer's Drugs Are Disappointing
By Cyndi Root
Two new studies published in the New England Journal of Medicine have dashed hopes for two experimental drugs for Alzheimer’s disease. The clinical trials for bapineuzumab and solanezumab proved that the drugs were ineffective in treating patients with mild to moderate dementia. The drugs’ expected course of action was to combat the amyloid beta protein plaques that tangle brain neurons. Instead, the medications did not improve thinking ability. Dr. Steven Salloway, lead researcher on the bapineuzumab study said, “We were disappointed there was no clear clinical benefit."
Bapineuzumab and Solanezumab
Bapineuzumab and solanezumab are antibody drugs. They bind to amyloid beta and help eliminate it. The clinical trials together included over 4,000 people. Both drugs were administered to patients intravenously, which researchers discovered was well tolerated. Even if the drugs failed, the delivery method was successful.
Bapineuzumab slowed or reduced amyloid buildup. The solanezumab trial was not as hopeful, as amyloid continued to increase. Eli Lilly is still planning to do clinical trials on solanezumab despite the poor showing in this study. Pfizer does not plan to conduct further trials on its drug, bapineuzumab. Steven Salloway, M.D. at Butler Hospital in Providence, R.I. said, “Amyloid plays an important role early in the disease process, so the earlier we can treat it the better the benefit.” Dr. Salloway sees future efforts directed along the lines of drug combinations, companies sharing data, and investigations outside of the amyloid beta problem.
The Alzheimer's Association works on its own and with other researchers on the amyloid beta issue, since it is one of the defining clinical features of the degenerative disease. Researchers acknowledge that drugs may not be effective once the tangles have infested the brain, so bapineuzumab and solanezumab may have value in the early stages as amyloid plaques form before the person shows symptoms.
The Association funds various kinds of research in an effort to understand different mechanisms like the immune system and its effect on the brain. Stakes are high with this disease, as it is not only prevalent and growing, but people have deep seated fears about losing their memories. Additionally, patients need caretaking help, effectively involving more people in the disease progression.