Efficacy and Safety Study to Evaluate Two Doses of Oral DMI-5207 in Adult Subjects With Diabetic Macular Edema

The drug being tested in this study is low doses of Optina (formerly known as Danazol) (DMI-5207) that may be an effective treatment for diabetic retinopathy and diabetic macular edema (DME). Laboratory studies have demonstrated that low doses of this drug may treat diabetic retinopathy and diabetic macular edema by two important ways, decreasing blood vessel permeability (related to leaking and edema) and by decreasing the formation of new leaky blood vessels. Optina is not approved by Health Canada for the treatment of diabetic macular edema but higher doses of Optina are approved by Health Canada for treatment of endometriosis (growth of cells similar to those that form inside of the womb that grows outside of the womb) and fibrocystic breast disease (a condition of the breast tissue). Higher doses of Optina have also been approved in the United States and many other countries since the mid-1970s in the treatment of men and women with hereditary angioedema (a disease which causes swelling in parts of the body) in addition to endometriosis and fibrocystic breast disease in women. All of the Optina doses that will be used in the current study are less than half of the typical starting doses for the approved indications. This can be compared to "high-dose" aspirin that is used to treat, for example, headache, while low-dose "baby aspirin" is used to reduce blood clotting. Similarly, Optina has two different effects at high and low dose. The low doses for this study have been selected based on the laboratory studies mentioned above. The purpose of this study is to investigate the safety and effectiveness of low doses of Optina in the treatment of macular edema due to diabetes, and also to test if it helps to slow the development of macular edema.