The topline results for the first phase II/phase III clinical trial of drugs to treat people genetically predisposed to early-onset Alzheimer’s disease were released on February 10. Those initial results showed that neither of the investigational drugs tested – gantenerumab or solanezumab – was successful at improving cognition or preventing cognitive decline in this population. However, the study investigators found that gantenerumab was associated with improvements in measures of amyloid and tau proteins and improvement in an overall measure of neurodegeneration (when nerve cells in the brain lose function over time).
On April 2 it was announced that an exploratory open-label extension (OLE) will be conducted to study the effect of gantenerumab over a longer period of time in this population. The extended study is expected to last two years and will be open to participants of the initial phase II/phase III clinical trial. Dr. Stephen Salloway, M.D. will continue on as the Project Arm Leader for the exploratory OLE.
The study is coordinated by the Dominantly Inherited Alzheimer Network Trials Unit (DIAN-TU), which is the clinical research arm of the Dominantly Inherited Alzheimer’s Network (DIAN). DIAN is an international Alzheimer’s research partnership focused on Dominantly Inherited Alzheimer’s Disease (DIAD), a rare form of inherited Alzheimer’s that strikes people in their thirties to fifties. The network is headquartered at and coordinated by Washington University School of Medicine in St. Louis; the Memory and Aging Program (MAP) at Butler Hospital is a founding member.
The initial trial included individuals who are at risk for developing DIAD – also known as autosomal dominant Alzheimer’s disease – in the future as well as those who have already been diagnosed with the condition. Topline results included all study participants regardless of where they were at in disease progression, or what dosage of trial drug they received. Deeper analysis of the study results is expected to shed light on whether either of the drugs had any success in treating subsets of the study’s participants (those not yet showing signs of the disease versus those with early disease) as well as variations in effectiveness depending on the level of dosage.
“This trial was a visionary study that would not have been possible without the participation of valiant volunteers,” Dr. Salloway said. “While the negative primary outcome was disappointing, we knew that there were some limitations in the initial study design that would prevent us from knowing if a larger sample size and longer treatment would yield better results. Now that the data is showing positive initial results on Alzheimer’s-related proteins with gantenerumab treatment, the exploratory open-label extension will allow us to study the effects of that drug specifically, in a larger number of people and over a longer period of time.”
The changes in amyloid and tau proteins with gantenerumab are impressive and Dr. Salloway is hopeful that we will learn a lot more in the exploratory open-label extension.
“The initial trial involved close collaboration between Washington University, the two different pharmaceutical companies involved, Roche and Lilly, and memory centers from around the world, with support from the Alzheimer’s Association and the National Institutes of Health, GHR Foundation and an anonymous donor foundation. It’s been an exceptional team effort to get this far, and this is the kind of public-private partnership we need to find an effective treatment for Alzheimer’s. Every lesson learned brings us another step closer,” Dr. Salloway said.
MAP Research Project Manager Courtney Bodge, Ph.D., who worked on the initial trial alongside Dr. Salloway and Ghulam Mustafa Surti, MD at the Memory and Aging Program, echoes those sentiments.
“Every study provides new and valuable information to advance the fight against Alzheimer’s disease. Even when the results don’t turn out as hoped, it’s extremely important to remember that doesn’t mean the study wasn’t worthwhile,” Dr. Bodge said. “Each study and every study participant plays a vital role in helping to find a cure. We’re so grateful for the participation and dedication of the participants in this trial, and we’re feeling positive about what lies ahead for advances in Alzheimer’s research.”
A participant in the DIAN-TU study at MAP echoed those sentiments and perhaps best exemplified the outlook that MAP researchers say is necessary to move forward against a foe as complex as Alzheimer’s, when she wrote to Dr. Salloway:
“Together we accomplished SO much and we’re on track for the discoveries we all dream about. As far as I’m concerned, the future is even brighter, and not too far away. This is not the time to get down, but up and running even faster. All of us bound together in this cause know disappointment all too well. We’re also no strangers to the unending hope and determination, and the endurance required to keep moving forward until we find the positive primary outcome we all seek. We’ll get there.”
Related Resources
Learn more about research studies at the Memory and Aging Program at Butler Hospital
CrossFitting for A Cure: How One Woman is Turning Fear Into Action in The Fight Against Alzheimer’s
If you're 40+ with normal memory or mild memory loss, you can help in the fight against Alzheimer's. Here's how: butler.org/ALZregistry
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