This is a randomised, double-blind, placebo-controlled, single ascending dose study in healthy volunteer subjects. Each dose level will be investigated with eight 20-50-year-old male subjects (6 on active drug and 2 on placebo). Additionally, eight healthy elderly subjects (65-80 years of age, males and females), 6 on active drug and 2 on placebo, will be included in the study at one dose level, once the safety and tolerability of AVLX-144 has been documented in younger subjects.

Inclusion Criteria:

- Healthy male and female subjects, body mass index (BMI) 18-28 kg/m2, body weight from 50 kg (females) or 60 kg (males) up to 100 kg, good general health.

Exclusion Criteria:

- History or evidence of current clinically significant cardiovascular, pulmonary, renal, hepatic, gastrointestinal, haematological, metabolic-endocrine, neurological, urogenital or psychiatric disorder. Febrile convulsions in childhood do not necessarily exclude a subject, but subjects with any type of generalized seizure in adulthood must be excluded. Personal or first-degree family history of congenital long QT syndrome or sudden death of a first-degree relative suspected to be due to long QT syndrome will also exclude the subject.