Detecting Alzheimer early: Dr. Sultan Darvesh pioneers diagnostic test
For nearly a decade, Dr. Sultan Darvesh has been on the hunt for a way to definitively diagnose Alzheimer disease in people while they are still alive – and before their cognitive functions have slipped below the threshold that allows for independence and quality of life.
“As it stands, the only way we can tell for sure that someone has had Alzheimer disease is to examine his or her brain after death,” explains Dr. Sultan Darvesh, a chemist, Capital Health neurologist and Dalhousie Medical School professor who’s affiliated with the Brain Repair Centre. “But the only way we can ever provide effective treatment is if we can positively identify the disease in its early stages.”
After synthesizing and screening hundreds of compounds, Dr. Darvesh and his collaborators have developed a small radioactive molecule that binds with butyrylcholinesterase, a key regulatory enzyme that accumulates in the Alzheimer-stricken brain.
“Our lead compound accomplishes a number of important feats,” Dr. Darvesh says. “It survives in the bloodstream, penetrates the blood-brain barrier, locates and binds to the butyrylcholinesterase in the brain, and lights up in nuclear imaging scans. It is potent, targeted and specific – just the qualities you need in a diagnostic agent.”
With help from a Brain Repair Centre Knowledge Translation Grant he received in 2013, Dr. Darvesh is now optimizing his lead compound to provide high-contrast, high-resolution images of butyrylcholinesterase using PET and SPECT technologies. He’s working with Drs. Steven Beyea and Chris Bowen in the Biomedical MRI Research Lab at the IWK Health Centre on pre-clinical tests. The researchers aim to have optimized molecules ready for clinical testing by 2016.
Other local support for Dr. Darvesh has come from Dalhousie Medical Research Foundation’s Adopt-a-Researcher program. “I have an adoptive mother whose generous donation has made a tangible impact,” Dr. Darvesh says. “We were able to use some of her gift to match an Atlantic Innovation Fund award that enabled Dr. Chris Bowen and his team to secure a PET/CT scanner for the Biomedical MRI Research Lab at the IWK – it’s a crucial piece of equipment for this work.”
Dr. Darvesh, who already holds six patents on the Alzheimer diagnosis technology, plans to take the compounds to market through Treventis Corporation, a spin-off company he and Dr. Don Weaver co-founded in Halifax to develop diagnostics and treatments for Alzheimer disease. While Dr. Weaver will expand the treatment side of the research and development from his new base as director of the Toronto Western Research Institute, Dr. Darvesh will lead the diagnostic arm from Halifax. “Treventis will be stronger than ever with this new arrangement,” he says. “There will be more resources to support the therapeutic work, which will benefit the company as a whole. This will have a positive impact on our diagnostics development. We need both the early-diagnosis and the disease-modifying agents to make an impact on people’s lives.”