(RxWiki News) A drug approved to treat a severe diabetic eye disease may soon be able to help with another.
A new study found that the drug ranibizumab (brand name Lucentis) may be highly effective in treating proliferative diabetic retinopathy (PDR). Lucentis was already approved in 2012 for the treatment of diabetic macular edema (DME), another diabetic eye disease.
For this study, researchers compared Lucentis with a type of laser therapy called panretinal photocoagulation, which has been the gold standard treatment for PDR since the 1970s.
"These latest results ... provide crucial evidence for a safe and effective alternative to laser therapy against proliferative diabetic retinopathy," said Paul A. Sieving, MD, PhD, director of the National Eye Institute, in a press release.
A potential complication of diabetes, diabetic retinopathy damages the blood vessels in the light-sensitive tissue that lines the back of the eye (the retina). As the disease worsens, these blood vessels can become distorted and lose their ability to function properly. PDR is the most advanced stage of diabetic retinopathy. If left untreated, PDR can lead to blindness.
"Diabetic retinopathy is caused by chronic high blood sugar levels, which promote leakiness within the network of small blood vessels that supply the retina, the light-processing layer of nerve cells located at the back of the eye," said Walker Winn, PharmD, in an interview with RxWiki News. "Diabetic retinopathy can be treated with drug injections that can inhibit growth and leakiness of these small blood vessels. Other treatment options include laser eye surgery focused on especially leaky vessels and steroid eye implants and injections."
According to the National Eye Institute, about 7.7 million people in the US currently have diabetic retinopathy. Of these, about 1.5 percent have PDR.
To test Lucentis against laser therapy for the treatment of PDR, a team of researchers led by Jeffrey G. Gross, MD, of the Carolina Retina Center in South Carolina, looked at 305 patients with PDR in one or both eyes.
These patients were randomly assigned to either undergo laser therapy or treatment with Lucentis for two years. For patients who had PDR in both eyes, one eye was assigned to laser therapy while the other was assigned to Lucentis.
Lucentis was injected into the affected eye once a month for three consecutive months — and then as needed for the rest of the study. About half of the eyes assigned to laser therapy required more than one round of laser treatment.
Because Lucentis is approved for the treatment of DME (a buildup of fluid in the retina), Dr. Gross and team allowed for the use of Lucentis to treat DME in the laser group when necessary. About 53 percent of eyes in the laser group received Lucentis injections to treat DME. Six percent of eyes in the Lucentis group received laser therapy to treat other eye complications.
After two years, Dr. Gross and team found that vision in the Lucentis group improved by about half a line on an eye chart on average. By comparison, virtually no improvement was found in the laser group.
Lucentis also resulted in only mild losses in side vision. Laser therapy resulted in substantial losses. The need for vitrectomy (a type of eye surgery) was also lower among patients in the Lucentis group than patients in the laser group.
These researchers said longer follow-up is needed, but Lucentis is a reasonable treatment option for at least two years for patients with PDR.
Rates of adverse events, such as cardiac arrest and stroke, were similar among both groups.
This study was published online Nov. 13 in the journal JAMA.
The National Institutes of Health, the National Institute of Diabetes and Digestive and Kidney Diseases, and the US Department of Health and Human Services funded this research.
Several study authors disclosed ties to pharmaceutical companies that make products used to treat diabetes.
