The purpose of the study is to evaluate safety and tolerability of 4SC-203 after a single dose administration in healthy volunteers.

Inclusion Criteria:

• Healthy male subjects aged 18 to 45 years (included), and in good health as determined by past medical history, physical examination, vital signs, electrocardiogram, and laboratory tests at screening
• Subjects must be able to communicate well with the investigator, to understand and comply with the requirements of the study, and to understand and sign the written informed consent

Exclusion Criteria:

• Evidence of current or previous clinically significant disease, medical condition or finding of the medical examination (including vital signs and ECG), that in the opinion of the investigator would compromise the safety of the subject or the quality of the data
• Current or recent history of significant renal, hepatic, haematological, immunological, gastrointestinal, endocrine, pulmonary, cardiac, neurological, or cerebral disease which would interfere with the subject's participation in the trial