A - 116 A Neuropsychological Testing Protocol for Assessing Lecanemab Eligibility for Alzheimer’s Disease: the First Fifty Patients

Abstract Objective Since the FDA approved lecanemab for Alzheimer’s disease (ad) treatment in 2023, neuropsychology’s role in the treatment eligibility determination process has become increasingly important. Not only is objective evidence of cognitive impairment required for the diagnosis of mild cognitive impairment (MCI) and mild dementia, but testing can be used to measure treatment efficacy and monitor for adverse effects. Our center developed a specialized protocol to assess cognitive and behavioral functioning for assisting in the eligibility determination process. Method Fifty adults (Mean Age = 73.8 years) underwent neuropsychological testing, including the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), as a part of their eligibility workup. Caregiver questionnaires were used to assess behavioral functioning. Test scores and patient outcomes were explored. Results Thirteen patients (26%) were prescribed lecanemab. Another 13 patients were deemed ineligible (five due to their cognitive results), eight patients (16%) were undecided, and 16 patients (32%) had not yet completed their workup. Of those who initiated lecanemab, eight patients (62%) had a diagnosis of MCI and six were diagnosed with mild dementia. Of these patients, eight (82%) showed an amnestic pattern on testing (RBANS Delayed Recall Standard Score Mean = 46.8). Additional analyses involving ad biomarkers, neuroimaging, and APOE status, were conducted. Conclusion Over one quarter of patients referred for neuropsychological testing as a part of their eligibility determination initiated lecanemab treatment for ad. Cognitive testing was directly related to determining ineligibility in 10% of patients. This review of an initial lecanemab treatment cohort highlights the importance of neuropsychology in the eligibility determination process.