A Study of Semorinemab in Patients With Moderate Alzheimer's Disease

Inclusion Criteria:

   - National Institute on Aging/Alzheimer's Association core clinical criteria for
   probable AD dementia

   - Evidence of the AD pathological process, by a positive amyloid assessment either on
   CSF Aβ1-42 as measured on Elecsys β-Amyloid(1-42) Test System OR amyloid PET scan

   - AD dementia of moderate severity, as defined by a screening MMSE score of 16-21
   points, inclusive, and a CDR-GS of 1 or 2

   - Availability of a person with sufficient contact with the participant to be able to
   provide accurate information on the participant's cognitive, behavioral and functional
   ability

Exclusion Criteria:

   - Pregnant or breastfeeding

   - Inability to tolerate MRI procedures or contraindication to MRI

   - Contraindication to PET imaging

   - Residence in a skilled nursing facility

   - Any serious medical condition or abnormality in clinical laboratory tests that, in the
   investigator's judgment, precludes the patient's safe participation in and completion
   of the study, or bias the assessment of the clinical or mental status of the
   participant to a significant degree

   - Any evidence of a condition other than AD that may affect cognition

   - Substance abuse within the past 2 years

   - Use of any experimental therapy within 90 days or 5 half-lives prior to screening,
   whichever is greater, or any passive immunotherapy against tau

   - Use of any passive immunotherapy (immunoglobulin) against Aβ, unless the last dose was
   at least 1 year prior to screening or any active immunotherapy (vaccine) that is under
   evaluation to prevent or postpone cognitive decline

   - Any other biologic therapy or previous treatment with medications specifically
   intended to treat Parkinsonian symptoms or any other non-AD neurodegenerative disorder
   within 1 year of screening

   - Systemic immunosuppressive therapy within 12 months of screening through the entire
   study period

   - Typical antipsychotic or neuroleptic medication within 6 months of screening

   - Daily treatment with any of the following classes of medication (except for
   intermittent short-term use): opiates or opioids, benzodiazepines, barbiturates,
   hypnotics, or any medication with clinically significant centrally-acting
   antihistamine or anticholinergic activity

   - Stimulant medications, unless the dose has been stable within the 6 months prior to
   screening and is expected to be stable throughout the study