Emory Eye Center retina specialists participated in clinical trials that have concluded a new drug holds hope in the treatment of age-related macular degeneration (AMD). Clinical trials at Emory and throughout the country have led to U.S. Food and Drug Administration (FDA) approval of Lucentis (ranibizumab injection), a new intravitreal drug that treats the "wet" type of macular degeneration. The drug is manufactured by Genentech.
Macular degeneration affects approximately 155,000 new Americans each year, with some 15 million people currently affected. In Georgia alone, some 35,000 people have the advanced form of AMD. For those over 60, it is the single largest cause of severe vision loss. According to the FDA, Lucentis is the first treatment, when taken in monthly doses, that can maintain the vision of more than 90 percent of newly diagnosed patients with wet AMD.
The approval was based on evidence from past clinical trials showing that Lucentis (ranibizumab) slows the progression of vision loss from advanced ("wet") AMD. Approximately one-third of patients in the trials had improved vision at 12 months.
Baker Hubbard, MD, a retina specialist at Emory Eye Center and principal investigator of the most recent trial at Emory evaluating Lucentis, says, "Central vision loss resulting from wet AMD can have a significant impact on someone's life. With this drug we now have a treatment option with the potential to significantly improve vision for more than one-third of patients with newly-diagnosed wet AMD."
Lucentis is designed to inhibit the formation and leakage of new blood vessels in the eye that can lead to wet AMD disease progression and central vision loss. Wet AMD affects the macula, the portion of the eye responsible for the fine, detailed central vision required for everyday activities such as reading, driving and recognizing faces. It occurs when blood vessels at the back of the eye grow and leak blood and fluid, causing damage to the macula. Symptoms include blurred, gray or blank spots in the center of the visual field and distortion that makes edges or lines appear wavy.
The National Eye Institute (NEI) of the National Institutes of Health (NIH) has funded nearly $95 million and sponsored more than 300 research studies investigating neovascularization, or angiogenesis--the growth of new blood vessels in the eye.
When researchers found that a protein--vascular endothelial growth factor (VEGF)--was indicated in the growth of new blood vessels in such diseases as AMD, pharmaceutical companies began developing anti-VEGF therapies. Among those approved for treatment are Macugen, and now Lucentis.
The FDA approval of Lucentis is based on data from two large Phase III clinical trials (MARINA and ANCHOR). In these studies:
- Nearly all patients (approximately 95 percent) treated with Lucentis maintained vision and up to 40 percent improved vision at one year, as measured on the Early Treatment of Diabetic Retinopathy (ETDRS) eye chart.
- On average, patients treated with Lucentis in the MARINA study experienced an improvement of vision at two years compared to a loss of vision in the control group. In the ANCHOR study, patients treated with Lucentis on average experienced a gain in vision at one year compared to a loss of vision in the control group.
- Up to 40 percent of patients treated with Lucentis achieved vision of 20/40 or better. In addition to data from the two pivotal studies, data from the Phase I/II FOCUS and Phase IIIb PIER studies were included in the FDA submission.
In clinical trials, the most common adverse reactions among patients treated with Lucentis (reported in at least 6 percent more patients than in the control groups in at least one study) included conjunctival hemorrhage, eye pain, vitreous floaters, increased intraocular pressure and intraocular inflammation. Although there was a low rate (less than 4 percent) of arterial thromboembolic events observed in the Luc entis clinical trials, there was no significant difference between the Lucentis and control groups, although there is a theoretical risk of these events with use of Lucentis. Serious adverse events related to the injection procedure occurred in less than 0.1 percent of intravitreal injections, including endophthalmitis, retinal detachments and traumatic cataracts. Other serious ocular adverse events observed among Lucentis-treated patients (occurring in less than 2 percent of patients) included intraocular inflammation and increased intraocular pressure. Lucentis is contraindicated in patients with hypersensitivity and ocular or periocular infections.
Prior to the formulation of Lucentis, Avastin, a drug used to treat colorectal cancer, had been coincidentally found to help those patients who also had advanced AMD. Avastin's chemical make-up is very similar to Lucentis, and ophthalmologists have used Avastin in past years to treat those patients.