From clinical trial to clinical experience: Lecanemab therapy in a real-world case series

The approval of anti-amyloid therapies has expanded therapeutic options for patients with Alzheimer's disease (AD), but the pivotal trials that proved their efficacy restrict their applicability to a selected patient population. We describe a case series of seven patients with biomarker-confirmed AD pathology evaluated in an academic memory clinic and treated with lecanemab whose characteristics would have disqualified them from trial participation. Patient histories and outcomes are presented, accompanied by description of the clinical team's reasoning and application of published Appropriate Use Recommendations for each case. Overall, lecanemab was largely well tolerated, with no unexpected safety concerns and amyloid-related imaging abnormality rates comparable to trial data. Clinically, most patients remained stable over the treatment period, though some continued to decline. This series highlights the challenges and considerations in applying disease-modifying therapies beyond trial populations, emphasizing the need for real-world data to guide treatment in diverse AD presentations.