Veeral Sheth, MD: Insights Into CST Fluctuations, Vision Outcomes with PDS Treatment

New findings suggest fewer than one-third of patients in the Archway trial of the Port Delivery System (PDS) with ranibizumab experienced clinically meaningful central subfield thickness (CST) fluctuations over 96 weeks.

The data additionally show visual acuity was similar across treatment arms, but those with CST fluctuations were observed to have experienced worse visual acuity.

The findings were presented at the American Society of Retina Specialists 40th Annual Scientific Meeting.

In an interview with HCPLive, presenting author Veeral Sheth, MD, University Retina, discussed the findings of the post-hoc analysis and what may be next for PDS.

He described the background of the study, particuarly highlighting the correlation between retinal thickness fluctuations and vision changes.

"Part of why people don't do well in the real world is because their retina tends to fluctuate, they get OCT variability along the course of their treatment, and over time, their vision declines," Sheth said. "We know with newer agents, we want durability. Because I think that is really what keeps the anatomy stable."

ARCHWAY patients were implanted with PDS with a Q24 week refill and were compared to those who received monthly ranibizumab. The data show nearly 70% of patients in both groups had no retinal thickness fluctuations.

"In that small percentage where we did see some fluctuations, those patients did tend to do a little worse from a vision standpoint, which is exactly what you would expect," Sheth noted. "But, the magnitude of that change wasn't very large at all."

Most patients did well and on average, ended up at 20/30 vision at the end of the study. The more durable the agent, the better the patient will do in the long run, Sheth said. He added that newer agents are lasting longer, which clincians have been looking for for a long time,

"Now that we've got them, we're starting to put them in place in the real world and starting to see the benefits of that and more importantly, patients are seeing the benefits of that," Sheth said.

He spoke on further safety signals of PDS itself, noting that higher rates of endophthalmitis was observed.

"I think that's why it's really important for people to be well educated on the surgical technique," Sheth said. "I think you see in the clinical trials that we learned a lot. As we modified our techniques, it looks like the procedure itself became safer over time."

Sheth noted that in a few years, clinicians will learn more about their patients and the vision outcomes. Historically, from a treatment standpoint, compliance and treatment burden issues tend to come up over time.

"With these new delivery devices, especially with PDS, if you're only having to refill it every six months, you're likely to see better outcomes in the long run," he added.