The purpose of this study is to evaluate the safety and effect of THR-4109 on weight loss in obese subjects over a 24-week treatment period.

Inclusion Criteria:

• 30 to 60 years of age
• Body mass index between 30 and 40 kg/m2
• Women of child bearing potential with a negative pregnancy test prior to entry and who agree to use an acceptable method of contraception throughout the study
• Able and willing to give written informed consent

Exclusion Criteria:

• Weight loss of more than 3 kg in the previous 3 months
• Current or previous use (within 3 months) of medications that influence weight
• Known endocrine origin for obesity, such as hypothyroidism and Cushing's syndrome
• Current or history of eating disorder such as bulimia, anorexia nervosa, binge eating or laxative abuse
• Current serious/unstable medical condition
• Current pharmacologically treated diabetes or fasting plasma glucose ≥ 126 mg/dL