Q&A: David S. Boyer, MD, on the suprachordial delivery of gene therapy

Photo of David S. Boyer, MD, taken at Retina World Congress 2025

David S. Boyer, MD, discusses a new approach to treating diabetic retinopathy and macular degeneration using suprachoroidal space injections. This innovative technique offers significant advantages over traditional intravitreal injections by providing a less invasive, office-based procedure with dramatically reduced inflammatory risks.

Note: The following conversation has been lightly edited for clarity.

Ophthalmology Times: Here at Retina World Congress 2025, you presented on suprachoridal delivery of gene therapy. What are some key takeaways that you hope people learned from your presentation?

David S. Boyer, MD: We broke [the presentation] up into 2 [sections]. The suprachoridal space is a very interesting space because of the fact it's an in office procedure, and it does not carry with it the significant inflammatory problems that can occur from intravitreal injections–it was non surgical.

We looked at 2 different categories of patients. We looked at patients with diabetes who had diabetic retinopathy severity basically between 47 and 53 and between 57 to 65 in later studies. So there were 3 cohorts, or 3 dosing regimens. There was 2.5e-11, 5e-11, and 1e-12. And we're just talking about the first 2 in the beginning.

There was definitely some interesting things that came out in the presentation. I didn't talk about the fact that they looked at NAV positive, NAV negatives, and really didn't see any significant alteration in the response. The overall take home message was the visual threatening complications were reduced tremendously by this treatment, which went from about 37% down to about 4% in the high dose, which is extremely important, because if you can treat somebody with one injection in the office, hopefully, which will last for a long, long time and reduce visual threatening complications, at least you have patients that will do well.
And certainly the studies did show that you can maintain vision in these patients with the treatment, and you definitely had in the higher dose, started to see a very good response of the diabetic retinopathy severity not getting worse, and actually somewhat improved over the period of time—at least 2 steps of improvement

In the macular degeneration again, the same doses, 2.5e-11, 5e-11, and 1e-12 were evaluated. And again, we showed maintenance of vision, maintenance of central retinal thickness, with 1 injection, and it reduced the number of rescues tremendously.

Ophthalmology Times: With this data in mind, what might the future of these suprachoroidal injections look like?

Boyer: So I think that we're getting to the point where these suprachoroidal injections are very, very helpful. They may be able to reduce the number of injections, and the safety was good. Topical drops were all that was necessary to reduce any intraocular inflammation. In fact, in the highest dose, there was no interactive inflammation when topical drops were utilized. So I think that as we go, and I don't think this is the last dosing, I think you can go higher, and if you go higher, we may be able to get even longer term and better results. So I'm hopeful that the suprachoroidal space will be evaluated, because it is easy to do in the office.

Ophthalmology Times: What do you think is the potential future for treating ocular diseases through the suprachorodial space?

Boyer: Well, I think that the safety is probably number one. The suprachoroidal space is a potential space, and it's in the office, and we get the best results with all the gene therapies with subretinal delivery, but it carries with it a risk of having surgery, the risk of developing a cataract, the risk associated with intravitreal, with retinal surgery and general vitrectomy surgery, though the risks are small, they're still not zero. Intravitreal injections have been shown to be helpful. And I think you know, we have two very strong programs for the 150 program, and we have the Adverum program that's going forward. The Adverum program had a little bit more inflammation than we'd like to see, I think that cutting the dose down is helped with that. And for DMT really has had a very good safety.