ARVO 2024: Insights on dry AMD and geographic atrophy from the GALE study of pegcetacoplan

The Eye Care Network is in Seattle, Washington, this week for the annual ARVO meeting. At the conference, Ash Abbey, MD, director of clinical research at Texas Retina Associates, presented 36-month data from the GALE study of pegcetacoplan. Here, he speaks about using pegcetacoplan for treatment of dry age-related macular degeneration, specifically geographic atrophy (GA).

Editor's note: The below transcript has been lightly edited for clarity.

Ash Abbey, MD: This is Dr Ash Abbey from Texas Retina Associates. I'm the Director of Clinical Research in Dallas, Texas. I'm here at the ARVO 2024 meeting to present the 36-month GALE data. So GALE is a long-term extension study of the use of pegcetacoplan for the treatment of dry age-related macular degeneration, specifically geographic atrophy. And what we've seen with the GALE data, essentially, we are looking at the patients who were in the phase 3 clinical trials of DERBY and OAKS, which led to the FDA approval of pegcetacoplan for the treatment of geographic atrophy.

And those patients had the option to roll over into a additional 3 years of treatment within a clinical trial known as GALE. All patients were treated in the trial with pegcetacoplan, either monthly or every other month. And what we find with the first year of data outside of DERBY and OAKS, so that's 3 years total of treatment is that there is an increasing treatment effect over time with the treatment of pegcetacoplan in terms of reduction of GA growth. We see at year 3, that there was a 35% reduction in GA growth, with monthly treatment and a 24% reduction with every other month treatment of pegcetacoplan. And if we focus primarily on just the non-subfoveal lesions, which tend to be the ones that grow faster than the foveal lesions, those specifically had an even more pronounced effect from the treatment of 42% reduction with monthly treatment at 3 years, and 28% reduction with every other month treatment at 3 years. Going into a little bit more of the visual outcomes now, we did do a hope do a post-hoc analysis of the DERBY and OAKS trials to look at the progression to severe visual impairment, which is defined as less than 2200 vision, and we found that there was a 38% risk reduction towards progression to severe visual impairment in patients who are receiving pegcetacoplan monthly. In addition, we looked at microperimetry data, and we found that the the risk reduction was quite significant towards the progression to an absolute scotoma, meaning a 0 to -1 reading on the microperimetry in both the four central loci of the macula, which corresponds to the central subfield, and also in the sixteen central loci of the macula of microperimetry, which corresponds to the entirety of the fovea. So we had a significant reduction in the risk towards absolute scotoma in all of these points with treatment with pegcetacoplan over the course of 2 years.

Finally, we get to safety data. Always important to note, we see that there were consistent safety signals that were found, sorry, there simply signals in GALE, in the first year, were consistent with the signals that we found in the first 2 years of DERBY and OAKS. No real differences in terms of incidence of new problems or adverse events. So just to conclude, we see that there, in the 3 years of treatment with pegcetacoplan, we have increasing treatment efficacy and the reduction of GA growth. We also see that we have some new data to demonstrate that visual outcomes in terms of preventing significant vision loss in these patients is starting to become more clear with these post-hoc analyses. And finally, we can see that safety data remains consistent with the previous 2 years of treatment. So this clinical trial, this extension study actually will be going on for a total of 3 years once patients are enrolled.

So, it was exciting to see that in December of 2023, the first patient completed the entirety of the trial, which means that patient had a total of 5 years of involvement in the clinical trials, which is what we're going for here. Those who are receiving consistent dosing, both in DERBY and OAKS, and now in the GALE study will end up having a total of 5 years of treatment with pegcetacoplan. And we'll be able to eventually analyse the very long-term data for those patients probably in the next couple of years, once the rest of the patients complete the trial. I would say that we are seeing an increasing effect over time with this treatment. So we are seeing the lines broaden, kind of space out even more between what would be the sham treatment, if you're not receiving any treatment, and a treatment group in terms of preservation of retinal tissue and reduction of growth over time. So the more we use it, over time chronically, the more of an effect we get.