New study shows refillable implant works as well as eye injections to treat blinding eye disease
NEW ORLEANS, La. – An implant that delivers medication to the back of the eye was found to effectively treat age-related macular degeneration (AMD) for at least six months. This represents a vast improvement over the typical regimen of nearly monthly eye injections. The implant offers more than convenience for patients and physicians, it provides an opportunity for more consistent treatment so people can better protect their vision from this devastating eye condition. The study will be presented today at AAO 2021, the 125th annual meeting of the American Academy of Ophthalmology.
Called the Port Delivery System (PDS), the permanent refillable implant, roughly the size of a grain of rice, is surgically implanted into the eye and continuously delivers a customized formulation of Lucentis (ranibizumab), a drug that improves vision for millions across the globe suffering from AMD. The implant is refilled every six months.
Lucentis was the first treatment found to slow the disease, allowing more than 90 percent of patients to keep their vision, according to clinical trials. However, in the real world, the percentage is closer to 50 percent. One of the main reasons for this difference is that patients are undertreated. This is because most people with AMD must go to the ophthalmologist’s office for eye injections every six to eight weeks. This can be a difficult schedule to maintain for many elderly patients struggling with other maladies and reliant on others to get them to their ophthalmologist visits.
To determine if the implant can deliver Lucentis as well as regular eye injections, researchers calculated the mean daily drug release rate during an initial fill and at three refill exchanges. About 70 percent of Lucentis 100 mg/mL was released from the implant during the 6-month period, said Mark R. Wieland, MD, at Northern California Retina Vitreous Associates in San Jose.
The mean active release rate was 3.95 μg/days at the initial fill and 3.99, 3.85, and 4.0 μg/days at the first, second, and third drug refill exchanges, respectively. Changing the initial concentration of Lucentis from 10 to 100 mg/mL increased the initial drug release rates from 2 to 17 μg/days. And 98.4 percent of those who received the PDS did not require supplemental treatment before the first refill-exchange at 24 weeks.
“Overall, it is impressive that we are able to demonstrate that PDS has efficacy equivalent to monthly injections of ranibizumab,” Dr. Wieland said. “In this study, we have been able to demonstrate that estimated drug release and actual drug release are nearly identical. This shows that we are able to tune PDS predictably. It is also notable that these concentrations are maintained over multiple refills in the lab, with different implants and different batches of ranibizumab. We can be assured that the concentration of ranibizumab remains reliably therapeutic over a 6-month period.”
The U. S. FDA last month approved the PDS, which was developed by Genentech and will be sold as Susvimo.
About the American Academy of Ophthalmology
The American Academy of Ophthalmology is the world’s largest association of eye physicians and surgeons. A global community of 32,000 medical doctors, we protect sight and empower lives by setting the standards for ophthalmic education and advocating for our patients and the public. We innovate to advance our profession and to ensure the delivery of the highest-quality eye care. Our EyeSmart® program provides the public with the most trusted information about eye health. For more information, visit aao.org.
Some Seniors May Be Eligible for a Free Eye Exam
For individuals age 65 or older who are concerned about their risk of eye disease, you may be eligible for a medical eye exam, often at no out-of-pocket cost, through the American Academy of Ophthalmology’s EyeCare America® program. This public service program matches volunteer ophthalmologists with eligible patients in need of eye care across the United States. To see if you or a loved one qualifies, visit EyeCare America to determine your eligibility. EyeCare America is co-sponsored by the Knights Templar Eye Foundation Inc., with additional support provided by Alcon and Regeneron.