Long-Term Diabetic Macular Edema Management with the Port Delivery System
Patients with diabetic macular edema (DME) maintained visual acuity improvements and retinal anatomy stability for up to four years using the ranibizumab port delivery system (PDS; Susvimo), according to updated data from the PAGODA trial presented at the American Society of Retina Specialists meeting. Patients initially assigned to the PDS saw a 9.4-letter improvement in best corrected visual acuity (BCVA) and a 211-µm reduction in central subfield thickness (CST) after 208 weeks.
The PAGODA trial, which randomized 634 patients, demonstrated that continuous anti-VEGF delivery via the PDS effectively manages DME while significantly reducing treatment burden. According to Luke Lindsell, OD, MD, of the Cincinnati Eye Institute, 95% of patients required no supplemental anti-VEGF injections outside of the device’s 6-month refill interval.
Clinical stability remained consistent even for those who transitioned to the PDS later. Patients who switched from monthly intravitreal ranibizumab (Lucentis) to the PDS at 64 weeks achieved improvements in BCVA, CST, and Diabetic Retinopathy Severity Scale (DRSS) scores comparable to the group that received the device at the start of the study. By the end of the 208-week follow-up, approximately 75% of participants across all groups maintained driving-level vision.
Pro Tip: When evaluating candidates for the PDS, clinicians often prioritize patients who struggle with the frequency of standard monthly intravitreal injections or those with irregular travel schedules who may benefit from the 6-month refill interval.
Safety Profile and Surgical Considerations
Long-term safety data for 559 PDS recipients showed no new safety signals. The most frequently reported adverse events included cataracts (27.0%), subconjunctival fibrosis or fluid (13.8%), and vitreous hemorrhage (11.3%). Serious adverse events occurred in 8.1% of patients, with conjunctival erosion noted in 2.1% of cases and endophthalmitis in 1.1%.
While patient satisfaction is high—with 80% to 90% of trial participants preferring the PDS over frequent injections—some specialists remain cautious. Charles Wykoff, MD, PhD, of Retina Consultants of Texas, noted that while the PDS offers a solution for long-term biologic storage, the surgical requirement to raise the conjunctiva introduces a risk of long-term exposure. “When there’s a black box warning on the package insert, that does change the conversation with patients,” Wykoff stated.
Future Trends in Retinal Disease Treatment
The PDS represents a shift toward reducing the clinical burden of chronic eye disease management. Beyond current anti-VEGF delivery, the field is exploring a variety of alternatives to traditional injections. According to Wykoff, future strategies likely include:
- Implants embedded with tyrosine kinase inhibitors.
- Tarcocimab anti-VEGF/biopolymer implants.
- Potential oral therapies or specialized eye drops.
These developments aim to address the “treatment burden” conundrum, where patients often delay care until progression occurs. The ability to store biological agents at body temperature for extended periods—as demonstrated by the PDS—remains a critical technical milestone for these future delivery platforms.
Did you know? The PDS platform allows for the continuous release of medication.
Frequently Asked Questions
How often does the Port Delivery System (PDS) require a refill?
The PDS is designed for a 6-month refill interval, significantly reducing the frequency of clinic visits compared to standard monthly intravitreal injections.
What were the most common adverse events in the PAGODA trial?
The most common all-grade adverse events were cataracts (27.0%), subconjunctival fibrosis or fluid (13.8%), and vitreous hemorrhage (11.3%).
Is the PDS effective for patients who have already received injections?
Yes. In the PAGODA trial, all patients had received prior intravitreal injections before device insertion, and both the upfront PDS group and the switch group showed sustained stability in visual acuity.
Why do some specialists still prefer standard injections over the PDS?
Some retina specialists, such as Charles Wykoff, MD, PhD, cite risks associated with the surgical procedure, such as potential conjunctival erosion, and note that the device carries a black box warning that necessitates careful patient selection and counseling.
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