A clinical trial funded by the National Institutes of Health has found that the drug ranibizumab (Lucentis) is highly effective in treating proliferative diabetic retinopathy, according to a National Institutes of Health news release. The trial, conducted by the Diabetic Retinopathy Clinical Research Network (DRCR.net) compared Lucentis with panretinal or scatter photocoagulation, which has remained the gold standard for proliferative diabetic retinopathy since the mid-1970s. The findings demonstrate the first major therapy advance in nearly 40 years.
“These latest results from the DRCR Network provide crucial evidence for a safe and effective alternative to laser therapy against proliferative diabetic retinopathy,” Paul A. Sieving, MD, PhD, director of NIH’s National Eye Institute (NEI), which funded the trial. The results were published online today in the Journal of the American Medical Association.
Treating abnormal retinal blood vessels with laser therapy became the standard treatment for proliferative diabetic retinopathy after the NEI announced results of the Diabetic Retinopathy Study in 1976. Although laser therapy effectively preserves central vision, it can damage night and side vision; so, researchers have sought therapies that work as well or better than laser but without such side effects.
The DRCR.net enrolled 305 participants (394 eyes) with proliferative diabetic retinopathy in one or both eyes at 55 clinical sites across the country. Eyes were assigned randomly to treatment with Lucentis or laser. For participants who enrolled both eyes in the study, one eye was assigned to the laser group and the other was assigned to the Lucentis group. About half of the eyes assigned to the laser group required more than one round of laser treatment. In the other group, Lucentis (0.5 mg/0.05 ml) was given via injections into the eye once per month for three consecutive months, and then as needed until the disease resolved or stabilized.
Because Lucentis is commonly used to treat diabetic macular edema—the build-up of fluid in the central area of the retina—the study permitted the use of Lucentis for diabetic macular edema in the laser group, if necessary. Slightly more than half (53 percent) of eyes in the laser group received Lucentis injections to treat diabetic macular edema. About 6 percent of eyes in the Lucentis group received laser therapy, mostly to treat retinal detachment or bleeding.
At 2 years, vision in the Lucentis group improved by about half a line on an eye chart compared with virtually no change in the laser group. There was little change in side vision with injection (average worsening of 23 decibels) but a substantial loss of side vision with laser (average worsening of 422 decibels). The vitrectomy rate was lower in the Lucentis group (8 of 191 eyes) than in the laser group (30 of 203 eyes).
Rates of serious systemic adverse events, including cardiac arrest and stroke, were similar between the two groups. One patient in the Lucentis group developed endophthalmitis, an infection in the eye. Other side effects were low, with little difference between treatment groups.
"We are pleased that the study, which compared the efficacy and safety of Lucentis (ranibizumab) injection to standard laser (PRP) therapy, met its primary endpoint of visual acuity in people with advanced (proliferative) diabetic retinopathy. People treated with Lucentis had an average improvement in visual acuity of +2.8 letters compared to a +0.2 letter improvement in the laser group. The publication also discusses other important outcomes including peripheral visual field impact, visual acuity over two years and rates of surgery in both treatment groups," Genentech said in a statement following the release of the data.
“Lucentis should be considered a viable treatment option for people with proliferative diabetic retinopathy, especially for individuals needing anti-vascular endothelial growth factor for diabetic macular edema,” Jeffrey G. Gross, MD, of the Carolina Retina Center in Columbia, South Carolina, who chaired the study. Dr. Gross presented results November 13, 2015, at the annual meeting of the American Academy of Ophthalmology in Las Vegas.
In addition to treating proliferative diabetic retinopathy, the report suggests Lucentis may even help prevent diabetic macular edema from occurring. Among people without diabetic macular edema at the start of the study, only 9 percent of Lucentis-treated eyes developed diabetic macular edema during the study, compared with 28 percent in the laser group. The DRCR.net will continue to follow patients in this study for a total of 5 years.
The DRCR.net is dedicated to facilitating multicenter clinical research of diabetic eye disease. The network formed in 2002 and comprises more than 350 physicians practicing at more than 140 clinical sites across the country. For more information, visit the DRCR.net website at https://drcrnet.jaeb.org