The Indianapolis-based drugmaker says the data show that the experimental drug Arxxant can reduce the rate of vision loss. Lilly announced the results Sunday but had included them in its February application to the Food and Drug Administration for Arxxant as a treatment for the disease, in which small blood vessels in the retina are damaged.
Diabetic retinopathy can lead to diabetic macular edema, the build-up of fluid in a part of the retina. Macular edema is the most common cause of vision loss among patients with diabetic retinopathy, Lilly says. Macular edema requires treatment by laser surgery to reduce the amount of fluid in the retina.
The clinical trial data demonstrate that Arxxant "has the potential to be the first oral therapy to specifically reduce the risk of vision loss by diabetic retinopathy," said Dr. Lloyd P. Aiello, lead investigator, in a press release from Lilly. Aiello is a researcher at the Joslin Diabetes Center in Boston and an associate professor of ophthalmology at Harvard Medical Center. Lilly unveiled the results at the annual scientific sessions of the American Diabetes Association in Washington, D.C.
Lilly said two clinical trials, whose data were combined, showed that 6.1% of Arxxant patients suffered vision loss, vs. 10.2% of patients receiving a placebo. Researchers measured patients' ability to read the lines on an eye chart; they defined vision loss as a three-line loss sustained for six months. The studies tested 813 patients over three years.
The late-stage clinical trial data have some qualifications. Although Arxxant achieved some success with certain forms of the disease called moderate to severe nonproliferative diabetic retinopathy, it didn¿t stop the disease from progressing to a more debilitating condition called proliferative diabetic retinopathy. In this most advanced stage, new, fragile blood vessels grow in the back of the eye. When they break and leak blood, they can cause severe vision loss and even blindness. Proliferative diabetic retinopathy requires surgery.
Lilly says an estimated 4.1 million U.S. adults 40 years and older have diabetic retinopathy, including 899,000 who have vision-threatening retinopathy. The National Eye Institute says that 40% to 45% of American diabetics have some form of this disease.
Despite Arxxant¿s promise in diabetic retinopathy, Lilly once had hopes that the drug would have more uses. Last August, the company announced that two clinical trials failed to meet goals for treating symptoms of diabetic peripheral neuropathy, or nerve pain associated with diabetes. Arxxant wasn¿t significantly different than a placebo.
Lilly shares finished last week at $51.74.