According to investigators, the implant can provide a sustained infusion of drug to the retina
The Port Delivery System (PDS) with ranibizumab (Susvimo; Roche/Genentech), an ocular implant that was recently approved to treat wet age-related macular degeneration, provides drug delivery over an extended period of time.
The implant provides a dose of 100 mg/ml that is released over 6 months. The implant was approved by the FDA based on the results of the Archway [NCT03677934] phase 3 study. This investigation compared results of the implant with the results achieved with injections of ranibizumab alone.
Retina specialists Mark R. Wieland, MD, and Jay Stewart, MD, looked at the implant’s release and refill/exchange efficiency in vitro and reported that “approximately 70% of the ranibizumab 100 mg/mL was released from the implant over 6 months, and levels were unmeasurable after 450 days.”
Specifically, the mean respective active release rates at 6 months, expressed as µg/day, were 3.95, 3.99, 3.85, and 4.00at the initial filling of the implantand at the first, second, and third refill/exchanges, they reported. They also found that, during refilling of the implant, approximately 98% of the previous implant contents were replaced with fresh drug in one 100-µL refill.
The investigators concluded that the PDS continuously and reproducibly delivers ranibizumab over the course of months while maintaining its potency.
Late last year, Genentech received approval from the US FDA for PDS with ranibizumab, the first wet, or neovascular, AMD treatment in 15 years to provide an alternative to standard-of-care eye injections needed as often as once a month.
According to Genentech, the treatment is for intravitreal use via ocular implant to treat people with wet AMD who have previously responded to at least 2 anti-vascular endothelial growth factor (VEGF) injections. The company stated that Susvimo is the first and only FDA-approved treatment for wet AMD that offers as few as 2 treatments per year.
“Susvimo represents a major advancement in the treatment of retinal disease, and is an important new option for patients with wet AMD,” Carl Regillo, MD, chief of Retina Service at Wills Eye Hospital in Philadelphia and an Archway study investigator, said in a statement. “With Susvimo, my patients now have an option that can help them maintain their vision as well as anti-VEGF injections, but on a more manageable twice-yearly treatment schedule.”
Genentech noted that Susvimo delivers ranibizumab continuously, offering patients living with wet AMD an alternative to anti-VEGF eye injections needed as often as once a month. The implant is surgically inserted into the eye during a one-time, outpatient procedure and refilled every 6 months. If necessary, supplemental ranibizumab treatment can be given to the affected eye while the Susvimo implant is in place.
In the Archway study, Susvimo was generally well-tolerated, with a favorable benefit-risk profile. However, the Susvimo implant has been associated with a 3-fold higher rate of endophthalmitis than monthly intravitreal injections of ranibizumab.
According to the company, many of these events were associated with conjunctival retractions or erosions. Appropriate conjunctival management and early detection with surgical repair of conjunctival retractions or erosions may reduce the risk of endophthalmitis.
Mark R. Wieland, MD
This article is adapted from Wieland’s presentation at the American Academy of Ophthalmology 2021 annual meeting in New Orleans, Louisiana. Wieland and Stewart are both consultants to Genentech.