The purpose of this Phase III open-label extension study is to evaluate the long-term safety of Tramiprosate (3APS) in patients with mild to moderate Alzheimer's disease.

Duration of treatment: 12 months. Patients who complete the Phase III clinical trial will be offered the opportunity to receive Tramiprosate (3APS) in an open-label extension study

Inclusion Criteria:

• The patient must have successfully completed the full 78-week duration of the double-blind CL-758007 study.
• Male or female (age 50 years and older): Female must be of non-childbearing potential (i.e. surgically sterilized or at least 2 years post-menopausal).
• Patient must be living in the community with a reliable caregiver. Participant living in an assisted living facility may be included if study medication intake is supervised and participant has a reliable caregiver.
• The patient must be presenting a reasonably good nutritional status.
• Signed inform consent from the patient or legal representative.

Exclusion Criteria:

Patients will not be eligible to participate in the study if they meet any of the following criteria:

• The patient participates in another drug trial during the study.
• The patient with a clinically significant and/or uncontrolled condition or other significant medical disease.
• The patient is unable to swallow medication tablets.