An implant that delivers medication to the back of the eye was proven to effectively treat age-related macular degeneration (AMD) for at least six months. This is a significant improvement over the current standard of nearly monthly eye injections.
The implant offers more than just convenience for patients and doctors; it also allows for more consistent therapy, allowing people to better preserve their vision from this potentially blinding disease.
The permanent refillable implant, called the Port Delivery System (PDS), is surgically implanted into the eye and continuously distributes a personalized formulation of Lucentis (ranibizumab), a medicine that improves eyesight for millions of people suffering from AMD throughout the world. The implant is refilled every six months.
According to clinical trials, Lucentis was the first drug discovered to halt the progression of AMD, allowing more than 90% of patients to maintain their vision. In the real world, though, the ratio is closer to 50%.
One of the main reasons for this difference is that patients are undertreated. This is because most patients with AMD must visit an ophthalmologist every six to eight weeks for eye injections.
This can be a tough schedule to maintain for many older patients who are suffering from other illnesses and rely on others to get them to their ophthalmologist appointments.
Researchers calculated the mean daily drug release rate during an initial fill and three refill exchanges to see if the implant can administer Lucentis as well as routine eye injections.
At the initial fill, the mean active release rate was 3.95 g/day, and at the first, second, and third drug refill exchanges, it was 3.99, 3.85, and 4.0 g/day, respectively.
Changing the initial concentration of Lucentis from 10 to 100 mg/mL increased the initial drug release rates from 2 to 17 g/day. 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 Port Delivery System (PDS) developed by Genentech was approved by the FDA last month.