Biomarker imaging and theranostics developer Precision Molecular Inc. (PMI) announced that it received an investment from the Alzheimer’s Drug Discovery Foundation (ADDF) to help fund the advancement of more effective ways to image neuroinflammation, with a view to discovery of early imaging biomarkers for Alzheimer’s disease. Terms of the investment were not disclosed.
“We welcome the investment by ADDF to help advance this important work,” said Martin Pomper, M.D, Ph.D., founder and CEO of PMI, in a press release. “We and others have used radioligands targeting the translocator protein for positron emission tomography (PET) in an effort to measure activated microglia—a hallmark of neuroinflammation—in patients with a variety of putative neuroinflammatory conditions. Unfortunately, that approach is fraught with poor cell selectivity and high variability.”
The company’s radiotracer, PMI04, binds the macrophage colony stimulating factor 1 receptor (CSF1R) which, in the brain, is found almost exclusively on microglia and infiltrating macrophages, cell types directly involved in inflammation.
“Imaging agents such as the one being developed by PMI are essential to advancing our ability to diagnose Alzheimer’s and to develop new therapeutics,” said Howard Fillit, M.D., founding executive director and chief science officer of the ADDF. “The ADDF is pleased to support this important work and we look forward to seeing the results of ongoing clinical studies.”
In an article published in PNAS, uptake of PMI04 in inflamed brain tissue was shown to be about twice that of healthy brain tissue in animal models. Likewise, binding in postmortem Alzheimer’s brain tissue was about twice that of healthy tissue. Radiotracer uptake could be completely blocked by pretreating with other CSF1R ligands, demonstrating high specificity for the target.
In addition to potential applications for detecting and following Alzheimer’s disease, this radiotracer can also be used to identify and track neuroinflammation in patients with Parkinson’s disease. In December 2019, Johns Hopkins University received a grant from the Michael J. Fox Foundation (MJFF) to study PMI04 for imaging microglia-selective inflammation in patients with Parkinson’s disease.