Targeting neuroinflammation
Dr. Tesi kicked off the session describing INmune Bio’s focus on neuroinflammation. The company’s drug candidate targets soluble tumor necrosis factor (TNF), which the company believes is a direct cause of Alzheimer’s disease through promotion of inflammation. He noted that TNF is a primary mediator of inflammation in rheumatoid arthritis, and patients with RA have an eightfold increased risk of developing Alzheimer’s disease, compared with the general population, while patients with RA who are taking anti-TNF medication have a 60% lower risk than the general population.
The company’s TNF inhibitor XPro is also unique in that it induces remyelination in mice, while other TNF inhibitors potentially “abuse” the brain by causing demyelination. Earlier research showed that it reduces neuroinflammation, improves nerve cell survival, and improves synaptic function. The company is conducting two phase 2 clinical trials, one in patients with mild cognitive impairment (MCI) and one in mild Alzheimer’s disease. They also use the MCI Alzheimer’s Cognitive Composite (EMACC) tool for assessing outcomes rather than the more commonly used Alzheimer’s Disease Assessment Scale-Cognitive subscale (ADAS-Cog). “ADAS-Cog is like trying to make sushi with an axe. It is designed for moderate to severe disease, and trying to use it for mild (Alzheimer’s disease) or MCI is a mistake. EMACC is purpose built for mild [AD] and MCI patients,” said Dr. Tesi.
Maintaining homeostatis
Next, Hans Moebius, MD, PhD, chief medical officer of Athira Pharma, described his company’s focus on the hepatocyte growth factor (HGF) receptor, also known as tyrosine kinase MET (HGF/MET). It plays an important role in brain development and homeostasis, and it is expressed at lower levels in the frontal cortex and hippocampus of patients with Alzheimer’s disease. The company’s small-molecule drug candidate boosts the HGF/MET pathway, leading to downstream neuroprotection and neurotrophic effects. It also promotes formation of new synapses.
Dr. Moebius presented the results of a phase 2 trial showing that the drug, called fosgonimeton, led to significant cognitive improvement compared with placebo. The company is conducting a phase 3 clinical trial.
Type 3 diabetes?
In his talk, John Didsbury, PhD, founder and CEO of T3D Therapeutics, framed Alzheimer’s disease as a disease of metabolic dysfunction. He believes alterations to glucose and lipids in the brain cause structural changes that lead to symptoms. He pointed out that the strongest genetic Alzheimer’s disease risk factor is a mutant form of the lipid transport protein APOE4.
“What we have is dysregulated glucose energy metabolism and lipid metabolism that really cause, in our mind, the structural event changes and the stress event changes – plaques, tangles, inflammation, etc. – but these events perpetuate the dysregulated metabolism. It’s a massive positive feedback loop that many have called type 3 diabetes – a brain-specific form of diabetes,” said Dr. Didsbury.
The company’s approach is to use systems biology to identify a drug target that can bypass multiple aberrant insulin signaling pathways. Its drug candidate regulates the expression of multiple genes involved in glucose metabolism. Dr. Didsbury presented interim results from a phase 2 study showing improvement over placebo.