Two pharmaceutical companies, Eisai and Biogen, have published the results of an 18-month human trial for their new drug, lecanemab. It's meant to treat people with early stages of Alzheimer's disease, a devastating condition that causes the majority of dementia cases and affects hundreds of thousands of Canadians. The results of the lecanemab trial are promising — the condition of people who were given the drug declined at a rate that was 27 per cent slower than those who were given a placebo. It's a glimmer of hope for those facing Alzheimer's disease, but questions about the new drug remain. Today, Mike Crawley, a reporter with CBC's health unit, is here to explain how the drug works and what it may mean for people living with Alzheimer's disease.