This is a long-term follow-up study to evaluate the safety following LX1001, a gene therapy, for participants who are APOE4 homozygotes with clinical diagnoses varying from MCI or dementia due to AD who have previously received LX1001. Study LX1001-01 was designed to assess the safety of LX1001 at 3 ascending doses (5.0 x 1010, 1.6 x 1011, 5.0 x 1011 gene copy [gc]/mL CSF), with each group consisting of approximately n=5 individuals for a total of approximately 15 participants for the entire study.~In this study, participants who have received LX1001 in the parent protocol (LX1001-01) will be followed for up to 260 weeks post gene therapy administration to assess the safety and efficacy parameters (~208 weeks within this study)
The primary purpose of this long-term follow-up study is to assess the long-term safety profile of APOE4 homozygote participants who were administered gene therapy (LX1001) for the treatment of Alzheimer's disease in Study LX100101. A secondary objective is to assess the biomarker as shown by the conversion of CSF APOE isoforms from APOE4 to APOE2-APOE4. Additional secondary outcomes include amyloid PET scan, CSF markers (including Aβ42, Aβ42/Aβ40 ratio T--tau, and P-tau), and quantitative MRI (and other biomarkers that may be informative for this therapeutic approach). Other secondary objectives include instruments to assess cognitive and clinical AD.