Diabetic Macular Edema Clinical Trial Results Announced
Ranibizumab (Lucentis) Treatment Shows Promising Results for Diabetic Eye Disease
Contact: Joana Casas, JDRF Media Relations
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NEW YORK, April 28, 2010 – A Phase II clinical trial showed that a drug combined with the current standard treatment of laser therapy is more effective than the current medical treatment in treating diabetic eye disease for people with type 1 and type 2 diabetes.
The two-year study compared the effectiveness of Lucentis, an antibody, licensed by Genentech, that blocks the leakage of fluid from the blood vessels in the eye that causes the retina to swell, to laser therapy for patients with Diabetic Macular Edema (DME) – a major complication of diabetes that can result in vision loss. Conducted by The National Eye Institute of the National Institutes of Health (NIH) and the Diabetic Retinopathy Clinical Research Network (DRCR.net), the research results were announced today in the online publication of the journal Ophthalmology.
The multi-center clinical trial was conducted by DRCR Network, and focused on the effectiveness on vision and retinal thickness from three treatments: laser treatment alone (the current standard treatment for DME that had previously been shown to be effective), Lucentis plus laser treatment, and a steroid drug plus laser treatment.
The researchers found that Lucentis (intravitreal ranibizumab) combined with the laser treatment improved vision significantly, compared with laser treatment alone. The steroid plus laser treatment showed an improvement in vision at 6 months, and declined thereafter.
“The results appear to apply to most people who have DME, regardless of whether the person has Type 1 or Type 2 diabetes, is old or young, or is a woman or a man. For eyes with a less serious form of DME, it is reasonable to apply laser, because previous studies have shown this to be beneficial (even if edema progressed into the macular center). Intravitreal ranibizumab as applied in this study should be considered for patients with DME and characteristics similar to the patients enrolled in this clinical trial”, says Neil M. Bressler, MD, representing the DRCR Network.
The randomized study enrolled 691 participants (854 study eyes); some patients had DME in one eye, and others with two eyes. The eyes were assigned randomly and equally to the following treatment groups: placebo plus a laser treatment called focal/grid photocoagulation, intravitreal ranibizumab (Lucentis) plus laser treatment, or intravitreal triamcinolone (steroid) plus laser treatment. The Lucentis plus laser treatment was further broken up into 2 subgroups; one group received laser soon after Lucentis was administered, and the other group received a delayed laser treatment 16 weeks following Lucentis. Lucentis injections were given as often as every four weeks, and steroid (triamcinolone) injections or laser treatments were given as often as every 16 weeks. Treatment was continued until a participant’s vision reached 20/20, retinal thickness returned to normal, or additional treatment did not improve vision or retinal swelling.
Based on the data published by the DRCR, approximately 50% of eyes treated with intravitreal ranibizumab improved by at least 2 lines on a standard eye chart, while fewer than 5% of eyes lost sight of 2 or more lines through at least the first year. In contrast, laser treatment alone resulted in only 28% of eyes improving by 2 lines and 13% losing vision of 2 or more lines at first year. In contrast to the Lucentis combination therapy, the steroid plus laser treatment showed an improvement in vision at 12 months, and declined thereafter.
In the ranibizumab group, only a few eyes lost more than 10 letters of vision from the time the study started, whereas eyes losing vision of more than 10 letters in the steroid group and laser-alone group gradually increased throughout the study. The occurrence of increasing ocular pressure and the need for cataract surgery was substantially greater in the steroid plus laser treatment group. In general, the effect of Lucentis and laser treatment on retinal swelling followed the vision improvement.
“JDRF is encouraged by these results. For the first time, a study has provided definitive proof that a combination of treatment and follow-up strategy can improve vision (for up to two years) in persons with diabetic eye disease”, says Barbara Araneo, PhD., the Director of Complications Therapies at JDRF. “The vision improvement seen in this study could enable someone to read the newspaper or drive a car and enhance overall quality of life for people with diabetes.”
JDRF partners with DRCR Network in support of clinical research directed towards diabetic retinopathy. Previous studies have used smaller subject numbers and a shorter time course. These have shown that Lucentis or other similarly acting drugs can improve vision and resolution of DME. The smaller number of cases with shorter follow-up evaluated in previous studies did not allow definitive conclusions to be made regarding the benefits of intravitreal ranibizumab for DME compared with laser treatment.
The investigators concluded that intravitreal ranibizumab with laser treatment, as applied in this study, should be considered for patients with DME.
Diabetic Macular Edema
Diabetic macular edema (DME) is swelling in the center of the retina, known as the macula. The retina is the light-sensitive tissue that lines the back of the eye. The macula provides detailed vision for activities such as reading, driving, or distinguishing faces. Swelling results from damage to the small blood vessels in the retina after years of elevated blood sugar levels from diabetes. The damaged blood vessels allow fluid to accumulate within the retina so the tissue swells, much like a sponge expanding with water. This swelling can subsequently lead to vision loss if the condition remains untreated. Diabetic retinopathy is the most common cause of vision loss in working-age Americans. Macular edema occurs when the blood vessels damaged by diabetic retinopathy begin to leak fluid, causing swelling in the center of the retina, known as the macula. DME affects approximately 28% of people, who have had diabetes for at least 20 years. The standard DME treatment for at least 25 years has been laser treatment of areas with abnormal blood vessels. The treatment can include application of laser within areas of thickened retina (focal treatment) and to other areas of thickened retina involving or threatening the macula in a pattern of spots spaced at least two burn-widths apart (grid treatment).
About the Diabetic Retinopathy Clinical Research Network
The Diabetic Retinopathy Clinical Research Network (DRCR.net) is a collaborative network dedicated to facilitating multicenter clinical research of diabetic retinopathy, diabetic macular edema, and related disorders. The DRCR.net was formed in September 2002 and has involved more than 200 clinical sites and more than 700 physicians. The DRCR.net is funded by the National Eye Institute and the National Institute of Diabetes and Digestive and Kidney Diseases of the National Institutes of Health.
Ranibizumab is an antibody designed to block a protein called vascular endothelial growth factor (VEGF), which is produced in excessive amounts in people with diabetes. VEGF causes leakage in the small blood vessels of the eye that can lead to vision loss and, eventually, blindness. Ranibizumab was approved by the U.S. Food and Drug Administration for the treatment of patients with a type of age-related macular degeneration in June 2006. In addition to the READ studies, Genentech is conducting two parallel, phase 3 trials studying the safety and efficacy of different doses of ranibizumab to treat diabetic macular edema.
JDRF is a leader in setting the agenda for diabetes research worldwide, and is the largest charitable funder and advocate of type 1 research. The mission of JDRF is to find a cure for diabetes and its complications through the support of research. Type 1 diabetes is a disease which strikes children and adults suddenly and requires multiple injections of insulin daily or a continuous infusion of insulin through a pump. Insulin, however, is not a cure for diabetes, nor does it prevent its eventual and devastating complications which may include kidney failure, blindness, heart disease, stroke, and amputation. Therapies to free people from the devastating health burden of complications that can accompany diabetes, including diseases of the eye, nerves, and kidneys, are an important focus of JDRF research; in the last fiscal year, the foundation invested more than $22 million in research involving Complications Therapies.
Since its founding in 1970 by parents of children with type 1 diabetes, JDRF has awarded more than $1.4 billion to diabetes research, including more than $100 million last year.
For more information, please visit http://www.jdrf.org/
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