New Retina Mechanisms Beyond Anti-VEGF Excite the Field: Paul Hahn, MD

More than 3 years after ranibizumab [Susvimo; Genentech], the first sustained-release surgical implant for wet age-related macular degeneration (AMD), reached the market, most retina specialists still are not using it, proof that approval, and even strong efficacy data, do not guarantee it a place in everyday practice, said Paul Hahn, MD, PhD, FASRS, founder of phRETINA, in an interview with The American Journal of Managed Care® (AJMC®).

Hahn first flagged that hesitancy in an interview years ago, when he said the device’s place in the retina armamentarium had yet to be defined.¹ Hahn revisits that prediction and explains what separates a “home run” therapy from a niche one, the operational hurdles standing between gene therapy and routine use, and why new non–vascular endothelial growth factor (VEGF) mechanisms, including Wnt pathway and Tie2-targeting agents, along with home-based retinal monitoring, are generating excitement that access barriers may still blunt.

This interview was edited for clarity.

AJMC: In an AJMC interview a few years ago, you said reception to the port delivery system among retina specialists was mixed,¹ and that its place in practice still needed to be defined by the field. Looking at where things stand now, including longer-term outcome data, has that place become clearer? Or does the device still occupy an uncertain niche?

Hahn: I would say the role for the port delivery system still remains uncertain. Despite more long-term data demonstrating efficacy and a more defined safety profile,² I think retina specialists have still been very reluctant to adopt it. In a large survey of over 1000 retina specialists sent out by the American Society of Retina Specialists [ASRS],³ we can see that most retina specialists still do not perform Susvimo surgical implantation.

Personally, I think the device is an important part of our armamentarium. I was part of the clinical trials, both the phase 2 and phase 3 trials for Susvimo, and I’ve seen remarkable improvements in patients, both in terms of treatment burden and in terms of important benefits from a drug delivery, pharmacokinetic, and pharmacodynamic standpoint. But I think there are just too many barriers to access that make it a challenge to adopt, and there are reservations among retina specialists about incorporating it into their armamentarium. Unfortunately, despite its benefits as a surgically implanted device, it just hasn’t taken off the way I think was projected.

AJMC: Beyond the port delivery system, there has been a wave of other sustained-release approaches in late-stage development. As someone who has run clinical trials, what separates a sustained-release technology that is going to change practice from the one that ends up a niche option?

Hahn: That’s one of the million-dollar questions: how do we know which of these options will be a home run? I think our current bar is very high. Our existing anti-VEGF therapies work extremely well in terms of efficacy, and in that same survey I referenced earlier, most retina specialists identify treatment burden as the most important unmet need, so we’re all looking for a drug that works longer.

But our bar for efficacy and safety is high, and I don’t think we have much tolerance to accept lower efficacy or, worse, safety. I really think what’s going to distinguish a home run from a niche product is the efficacy and safety profile. Many of these products are associated with at least some potential trade-off, and how they function in the phase 3 trials, and in our real-world experience, will dictate what becomes an important part of our armamentarium versus a niche product.

AJMC: Gene therapy for AMD is becoming very realistic. From a surgical and practice-logistics standpoint, what does it take to bring gene therapy into practice, and is the field ready for it operationally?

Hahn: There are different types of gene therapy being developed. Some involve surgical implantation of the gene therapy product, some involve a specialized suprachoroidal injection, and some involve intravitreal injection. The most plug-and-play option would be the intravitreal injection, and it will be the easiest to incorporate into the operation of an existing retina practice. As retina specialists, we’re all very familiar with intravitreal injections, and injecting a gene therapy product isn’t much different. There’s an operational aspect around storage; it probably requires a special –80-degree freezer, but a lot of that depends on the final product.

Suprachoroidal injections will likely require resources that are already accessible to retina specialists in their current practice, though the technique itself may not be fully familiar to everyone, and that will require some learning, which is always a barrier to uptake. I think the most challenging will be surgical implantation. Operationally, the surgical procedure isn’t very different from procedures we may already do in our existing ORs [operating rooms], so that can be incorporated fairly easily, but there are barriers around access to OR time that can be a challenge in incorporating a surgical approach. We’ve seen that with Susvimo, for example. As retina specialists, one challenge we’re experiencing from a practice-management standpoint is access to the OR, and one of the ways that may manifest is difficulty incorporating new surgical technologies or procedures into our practice.

AJMC: Switching gears, there’s a new class of agents targeting mechanisms entirely outside the VEGF pathway. Wnt pathway agonists and Tie2-targeting bispecifics work in part by trying to restore the blood-retinal barrier directly rather than blocking a growth factor. How significant is this conceptual shift? Could it reduce reliance on anti-VEGF therapy, or would the 2 approaches be used in tandem?

Hahn: Earlier we talked about that ASRS Preferences and Trends survey, where most retina specialists identify treatment burden as the biggest unmet need. Personally, what I’m most excited by are novel mechanisms of action. I think our existing anti-VEGF options are extremely effective, but they work in a very specific and defined way, and we do have patients who are refractory or who don’t respond optimally. Our ability to target those patients and improve outcomes is exciting to me.

The new agents that target a novel pathway, the Wnt signaling pathway, have the potential to change the way we treat these diseases. They’re in phase 2, and their early clinical trial data have been very exciting; we’ll see whether those same results hold up in the phase 3 data. Ultimately, how they’re used will depend on what the phase 3 data show, and how they get incorporated into our armamentarium will depend on our real-world experience. We’ve seen plenty of cases where exciting phase 2 data don’t translate into phase 3 efficacy, so even though I’m optimistic, I think it’s still important to await the actual data.

AJMC: Speaking of real-world use, as we talk about longer-acting drugs and clinic-schedule changes, that brings up the role of the patient at home. Where does home-based monitoring for patients with AMD stand today, and who realistically has access to it first?

Hahn: Home-based OCT [optical coherence tomography] imaging is another exciting technology. I think most retina specialists are excited about the opportunity for patients to get home-based OCT, where we can monitor their retinal scans not just at every monthly or greater visit, but across a much greater frequency.

Despite that excitement, there have been access issues with home-based OCT. From a reimbursement standpoint, it just hasn’t hit a place where it’s accessible to practices and, more important, to patients. This has been a battle for at least a couple of years, and at least where things stand now, I believe patients are generally paying out of pocket for it. With that being the case, utilization, as far as I’m aware, is not very high, and I don’t think it will be until appropriate mechanisms are in place for practices to incorporate this appropriately. That’s a shame. I think home-based OCT has huge promise, but access-to-care issues have prevented patients from being able to access this care.

AJMC: If home monitoring technology does mature and become more widely accessible, how would it actually change the treat-and-extend model? Would it let patients safely go longer between in-office visits, or would it mostly serve as an early-warning system that brings them in sooner when something changes?

Hahn: A lot of it depends on how effective it is. In my experience, the device is very effective, very reliable, and gives important information, so I think both of those things will be the case. I think it’ll allow patients to go longer between visits, because we can monitor when their fluid returns rather than depending on a wait-and-see approach. Rather than treat-and-extend, we’ll probably have new paradigms of treatment where we can treat, then monitor when fluid comes back, and treat patients at a more personalized level than even our treat-and-extend protocols allow. It’ll also serve as an important early-warning system: for patients who, for some reason, develop an unexpected recurrence of fluid or other problems, we can bring them back into the office sooner rather than later.

I think what’s most important is that, as a field, we’ve often found new ways to optimize technologies beyond what we originally expected. I’d predict that if we, as retina specialists, had access to this care, we’d find new, innovative ways to take advantage of it, apart from the obvious benefits of extending visits, reducing the number of injections, treating patients at a more optimal time, and using it as an early-warning system.

References

1. Joszt L. Dr Paul Hahn: Retina field has been rife with therapeutic changes. AJMC. November 1, 2022. Accessed July 10, 2026. https://www.ajmc.com/view/dr-paul-hahn-retina-field-has-been-rife-with-therapeutic-changes

2. Roche’s Susvimo maintains vision over five years with two refills per year in people with neovascular age-related macular degeneration (nAMD). News release. Roche. July 31, 2025. Accessed July 10, 2026. https://www.roche.com/media/releases/med-cor-2025-08-01

3. Hahn P, ed. ASRS 2025 Preferences and Trends Membership Survey: Chicago, IL. American Society of Retina Specialists; 2025. Accessed July 13, 2026.