Focusing on neurotoxic proteins
The final presentation of the session was by Maria Maccecchini, PhD, founder, president, and CEO of Annovis Bio. The company’s drug, buntanetap, reduces expression of a range of neurotoxic proteins. The downstream effects include restoration of axonal transport, reduction of inflammation, and protection of nerve cells. The company believes that Alzheimer’s disease results from acute and chronic stress events that lead to high levels of neurotoxic proteins, which include A-beta, tau, alpha-synuclein, and TDP43. The proteins aren’t just players in Alzheimer’s disease – they are present in abnormal levels in Parkinson’s disease and a range of other brain pathologies.
“In the brain of an Alzheimer’s and of a Parkinson’s [patient], you’re going to find all four proteins. You’ll find them in different concentrations, at different time points, in different brain areas. If you just remove one, you still have the other three that cause impairment in axonal transport, and that leads to inflammation that leads to neurodegeneration,” said Dr. Maccecchini.
The company’s drug manages to reduce levels of all four proteins by binding to a segment of messenger RNA (mRNA) shared by all of them. mRNA serves as a template for protein synthesis. Under normal conditions, the neurotoxic protein concentrations are kept low because the mRNA segment remains bound to a regulatory protein that prevents synthesis from occurring. However, when stress leads to high levels of iron, this regulatory binding protein releases the mRNA segment (along with the rest of the mRNA). The freed mRNA becomes available to the cell’s protein synthesis machinery, which starts producing high levels of neurotoxic proteins. Annovis Bio’s drug improves the ability of the regulatory protein to bind to the mRNA segment, preventing protein expression even in high-iron conditions. It works on all four neurotoxic proteins because they all have the regulatory segment in their mRNA.
The drug led to improvements in phase 2 studies of Alzheimer’s disease and Parkinson’s disease, and the company is currently recruiting for a phase 3 study in Parkinson’s disease and a phase 2/3 dose-response study in Alzheimer’s disease.
Combination treatments for a complex disease
Taken together, the presentations provided a snapshot of the post–A-beta/tau Alzheimer’s development world, and the future could be messy. Alzheimer’s disease and other dementias are likely to require combination treatments, according to Dr. Snyder. “This is a complex disease, not just Alzheimer’s but other dementias. It’s not going to be a single drug, a single target. It’s going to require some type of combinatorial approach, whether that be with medication and lifestyle interventions, or risk reduction, and different medications,” she said.
The latest results are good news for that approach: “We’re seeing that maturation of the science in these trials,” said Dr. Snyder.
Cheng Fang, PhD, senior vice president of research and development at Annovis Bio, agreed with that sentiment. “I believe [Alzheimer’s disease and dementia] is a very complicated disease. I always call them diseases instead of a disease because it’s a spectrum. I don’t believe one drug can cure them all, as much as I am confident in our drug. I think it’s extremely important to encourage this kind of diverse thinking,” said Dr. Fang.
Dr. Snyder has no relevant financial disclosures. Dr. Tesi, Dr. Moebius, Dr. Didsbury, Dr. Maccecchini, and Dr. Fang are employees and in some cases stockholders of their respective companies.