The following transcript has been edited for clarity.

Hi, I'm Nikolas London, MD, MS, FACS, and I presented on the year 3 results of the phase 2 ALTITUDE study evaluating sura-vec (surabgene lomparvovec, or ABBV-RGX-314) in patients with nonproliferative diabetic retinopathy (NPDR). I’m very excited to present the novel 3-year results. Just as a disclosure, I’m an investigator on multiple Regenxbio and AbbVie clinical trials.

We typically follow patients with NPDR in our clinic until they develop a vision-threatening complication. The reason is that, otherwise, to prevent those we really need to do repeated intravitreal injections. Sura-vec, the investigational product, is an AAV8 vector that encodes for an anti-VEGF antibody fragment. This is delivered into the suprachoroidal space in the office as a 1-time injection. The way I think about it, it turns the eye into an anti-VEGF biofactory.

The ALTITUDE phase 2 trial randomized patients 3:1 to sura-vec vs observational control and followed patients until the primary endpoint at 1 year, which was looking at the proportion of patients with a 2-step-or-greater DRSS improvement. And then patients had the opportunity to go on into a long-term follow-up. Patients in the control group could cross over.

The study included 3 dose levels. We’re going to focus on dose level 3, which is the dose being carried forward in the pivotal study, NAAVIGATE, which is now enrolling. Patients in dose level 3 received 7 weeks of prophylactic corticosteroid eye drops. Those patients received 1×10¹² genome copies/eye. It’s important to note that in ALTITUDE, eyes could be treated for diabetic retinopathy at investigator discretion. There were no set retreatment criteria, and we’re going to be focusing on the NPDR subpopulation.

So what we saw is that, compared to control, dose levels 2 and 3 showed a strong signal. In the control group, we saw about 42% of patients that had a 2-step-or-greater worsening in their DRSS score compared to 0% in dose levels 2 and 3. In dose levels 2 and 3, we also saw about a 20% 2-step-or-greater DRSS improvement.

Year 3 is where we saw separation between dose levels 2 and 3. At year 3, we saw 60% of patients with a 2-step-or-greater DRSS improvement compared to 0% in dose level 2. So very impressive.

One thing that’s also very interesting: in the presentation, you might see that there was a swim-lane plot showing all of the patients on the individual level baseline year 1 and year 3. The 6 patients that I mentioned, if you look at them at year 1, they had improved, but they continued to improve at year 3 without any further injections, with no further retreatment, and no vision-threatening events. So it appears that the treatment effect continues spontaneously, which is a very exciting finding for us.

Safety was great. There were 50 patients that were treated with sura-vec. There were 34 serious adverse events (SAEs), none of which were felt to be drug related. In dose level 3, with prophylactic corticosteroids, there were no cases of intraocular inflammation. There were 3 patients that had episcleritis about 1 to 2 weeks after stopping that prophylactic course of corticosteroids. And there were 3 patients with ocular hypertension that was mild to moderate and controlled with eye drops. So overall, a nice strong safety signal.

In summary, we’ve got a 1-time medication, sura-vec, that in at least 20% of our patients at year 3 in dose levels 2 and 3 led to a 2-step-or-greater DRSS improvement. We see a nice safety signal with no SAEs that we feel are drug related. And we hope that this is a continuing beneficial treatment option for our patients with diabetic retinopathy for years to come.

We are now enrolling in the NAAVIGATE phase 2b/3 clinical trial. Thank you. RP