New Treatment for Diabetic Macular Edema Available in Europe and Canada

Eye diseases leading to blindness are consistently ranked among the greatest fears of people with diabetes, and the most common of these eye diseases is called diabetic retinopathy. Indeed, in the US it is estimated that 40% to 45% of people with diabetes have some form of the condition. Diabetic retinopathy involves damage to blood vessels around the retina (the part of the eye that senses light and color), which can lead to blindness in several ways. For example, in diabetic macular edema (DME), diabetic retinopathy causes blood vessels to leak fluid into the macula, the part of the retina that is responsible for sharp, straight-ahead vision. The fluid causes the macula to swell and leads to vision impairment. Up to 75,000 new cases of DME develop each year in people with diabetes, and the consequences are dire – DME is a leading cause of blindness among working-age Americans. Currently, the gold standard for DME treatment is laser surgery, which involves sealing up the leaking blood vessels to reduce the amount of fluid around the macula. In studies, laser surgery reduced the risk for moderate vision loss by 50% over three years, but the operation can also be expensive and debilitating – especially over the long term. However, a new and potentially more effective treatment was recently approved in both Europe and Canada: a drug called Lucentis. Made by Roche (the makers of Accu-Chek strips) and sold by Genentech in the US (and Novartis internationally), Lucentis is already used to treat other eye conditions, including wet age-related macular degeneration (wet AMD). It is injected monthly or less frequently into the eye, where it works by blocking the activity of a molecule (VEGF) that promotes blood vessel growth and blood vessel leakiness. In European studies, Lucentis provided people with DME greater improvements in visual acuity (measured by the number of letters read on an eye chart) versus laser therapy or non-active injections (the control treatment) after one year. More recently, two-year studies conducted in the US have shown that Lucentis improves the eye function of people with DME compared to placebo (inactive) injections. In all these studies, Lucentis has been found to be generally safe and well tolerated; the major downside seems to be price, roughly $2,000 per shot, before insurance. (Avastin, a drug similar to Lucentis that is approved for treatment of cancer, is already used ‘off-label’ by some doctors to treat DME; it is dramatically cheaper per injection, but its safety and efficacy have not been as thoroughly investigated.) Excitingly, Lucentis itself is now on track for use in DME in the US. Earlier this month, Lucentis was submitted to the FDA for the treatment of DME, placing a possible approval around the summer of 2012. --BK