(300 WORDS MAX.) IRL752 is a new small molecule compound which is intended to treat the symptoms and to improve the long term outcome in Alzheimer's disease. IRL752 is a cortical enhancing drug; it selectively increases the content in the cerebral cortex of the neurotransmitters dopamine and norepinephrine which are reduced in Alzheimer's disease. Although IRL752 has a very strong effect on the key cortical areas affected by the disease it does not appreciably affect other brain regions. This means that IRL752 is devoid of the common side-effects associated with increasing neurotransmitters like dopamine and norepinephrine across brain regions. IRL752 has undergone safety and toxicological studies in experimental animals. It has also been studied in healthy male volunteers. The project aims at exploring the utility of IRL752 in patients with various stages of Alzheimer's disease. First, a small study will test the tolerability and safety of IRL752 in a limited number of patients. There will also be included a simple and harmless neurophysiological test to study its effects on the function of the cerebral cortex. If this smaller study comes out well it will be followed by a larger and longer duration study where the effects of IRL752 will be investigated in patients with moderate to severe Alzheimer's disease. This study is aimed to get a meaningful answer to whether the compound can improve symptoms and signs of the disease.