An Open-Label Crenezumab Study in Patients With Alzheimer's Disease

Inclusion Criteria:

- Previous participation in Study BN29552 or BN29553 and completion of the Week 105
visit.

- Able to provide written informed consent by the patient or legally authorized
representative, if required.

- Every effort to have the same caregiver participate throughout the duration of the OLE
(Open Label Extension) study who also participated in Study BN29552 or BN29553.

- Willingness and ability to complete all aspects of the study [including MRI (Magnetic
Resonance Imaging), lumbar puncture [if applicable], and PET (Positron Emission
Tomography) imaging [if applicable].

- Adequate visual and auditory acuity, in the investigator's judgment, sufficient to
perform the neuropsychological testing.

- For women of childbearing potential: agreement to remain abstinent (refrain from
heterosexual intercourse) or use a protocol approved contraceptive method and
agreement to refrain from donating eggs for at least 8 weeks after last dose.

- For men: agreement to remain abstinent (refrain from heterosexual intercourse) or use
a protocol approved contraceptive method for at least 8 weeks after last dose.

Exclusion Criteria:

- Patients who discontinued treatment permanently in Study BN29552 or BN29553 for safety
reasons.

- Impaired coagulation.

- Evidence of more than 10 microbleeds and/or ARIA-H (amyloid-related imaging
abnormalities-hemosiderin deposition) at the Study BN29552 or BN29553 Week 105 visit,
as assessed by central review of MRI.

- Diagnosed with three recurrent, symptomatic ARIA-E (amyloid-related imaging
abnormalities-edema/effusion) events or exacerbations of previous events.

- Presence of intracranial lesion that could potentially increase the risk of CNS
(Central Nervous System) bleeding.

- At risk of suicide in the opinion of the investigator.

- Alcohol and/or substance abuse or dependence within the past 2 years and during the
study.

- Inability to tolerate MRI procedures or contraindication to MRI, including, but not
limited to, presence of pacemakers not compatible with MRI, aneurysm clips, artificial
heart valves, ear implants, or foreign metal objects in the eyes, skin, or body that
would contraindicate an MRI scan; or any other clinical history or examination finding
that, in the judgment of the investigator, would pose a potential hazard in
combination with MRI.

- Pregnant or lactating, or intending to become pregnant during the study.

- Any other severe or unstable medical condition that, in the opinion of the
investigator or Sponsor, could be expected to progress, recur, or change to such an
extent that it could put the patient at special risk, bias the assessment of the
clinical or mental status of the patient to a significant degree, or interfere with
the patient's ability to complete the study assessments.

- Chronic use of anticoagulants or participation in any other investigational drug
treatment trial.