Diabetic Macular Edema

Diabetic macular edema (DME) is a serious manifestation of diabetic retinopathy that involves retinal swelling brought on by the leaking of fluid from small blood vessels within the macula. As the condition develops, central vision becomes blurred. DME can progress fairly rapidly and over just a few years can lead to permanent visual loss. There is a significant unmet need to both reverse the visual loss associated with DME and to help delay the progression of this condition.

Diabetes is a common and chronic condition for which there is no cure. Fifteen years after the diagnosis of diabetes, approximately 20% of affected patients develop DME. Currently in the U.S., there are more than 20 million individuals, or seven percent of the population, with diabetes. Industry experts expect the number of patients in the U.S. affected by DME, the leading cause of visual impairment among individuals with diabetic retinopathy, to reach 1.5 million by 2010. As the prevalence of diabetes increases, the number of individuals with DME will also grow. The total U.S. market for DME therapeutics is expected to grow to more than $580 million by 2010.

MacuSight has completed a Phase 1 clinical trial of its sirolimus product candidate in patients with DME. Results from this prospective study of 50 patients with chronic, refractory DME demonstrated that MacuSight's proprietary formulation of sirolimus was safe and well-tolerated in all doses tested with two different routes of administration (subconjunctival injection and intravitreal injection). The study showed no evidence of increased intraocular pressure or inflammatory response to treatment.

In addition to safety and tolerability data, the study provided an initial assessment of sirolimus' biological activity in DME. At 45 and 90 days following treatment, patients receiving the two lowest doses of sirolimus by subconjunctival injection demonstrated mean improvements in visual acuity over baseline using a standard (ETDRS) eye chart. Additionally, this group of patients also experienced anatomical improvements, with mean decreases in foveal thickness that were consistent with the observed functional improvements in visual acuity. Data for these patients at 180 days following treatment suggest that these improvements were maintained, or even enhanced over time, in many patients.

The company is initiating a Phase 2 clinical trial in DME.

• Disease Targets
• Wet AMD
• Diabetic Macular Edema
• Additional Opportunities

"The total U.S. market for DME therapeutics is expected to grow to more than $580 million by 2010."