Inclusion criteria:

• Male or female subject who has successfully completed the 12 Month Visit of 49653/461 (12 months of treatment) without tolerability issues, where in the opinion of the subject and of the investigator, it will be beneficial to continue treatment with RSG XR.
• Female subjects must be post-menopausal (i.e. >6 months without menstrual period), surgically sterile, or if of child-bearing potential, using effective contraceptive measures (oral contraceptives, Norplant, Depo-Provera, an intra-uterine device (IUD) a diaphragm with spermicide or a condom with spermicide). Women of childbearing potential must use effective contraceptive measures throughout the study and for 30 days after discontinuing study medication. The subject and their caregiver must ensure that the subject will continuously use contraceptive measures throughout the duration of the study.
• Subject is willing to participate in the extension study and has provided full written informed consent prior to the performance of any protocol-specified procedure; or if unable to provide informed consent due to cognitive status, full written informed consent on behalf of the subject has been provided by a legally acceptable representative[1].[1] Where this is in accordance with local laws, regulations and ethics committee policy.
• Caregiver has provided full written informed consent on his or her own behalf prior to the performance of any protocol-specified procedure.

Exclusion criteria:

• Subject had a serious adverse experience (SAE) or clinically significant laboratory abnormality during 49653/461, which in the opinion of the investigator could have been attributable to study medication, and which is ongoing at the end of 49653/461.
• The subject is felt by the investigator to be unsuitable (on the basis of health, compliance, caregiver availability, or for any other reason) for inclusion in the study based on the entry criteria for the primary study, 49653/461 (exclusive of the age criteria which may not be applicable to some of the subjects).
• The subject experienced a significant cardiovascular event during 49653/461 (e.g. intervention, percutaneous coronary intervention, vascular surgery, acute coronary syndrome [non Q-wave myocardial infarction, Q-wave myocardial infarction, unstable angina] or significant arrhythmia), unless a thorough cardiovascular evaluation has been performed which confirms that the subject does not have congestive heart failure, and is clinically stable.
• Treatment with a cholinesterase inhibitor, selegiline, memantine or any other treatment for cognitive symptoms/AD is initiated at the end of 49653/461.