Wet Age-Related Macular Degeneration: Understanding Disease Impact and Refining Treatment Approaches - Episode 6
Diana Do, MD, provides insight into anti-VEGF treatment selection for individual patients, evaluation of patient response to therapy, and considerations for switching of agents.
Diana Do, MD: In clinical practice when patients with wet AMD [age-related macular degeneration] present to a retina specialist, we look at the constellation of their findings and then make a recommendation on which intravitreal VEGF inhibitor to start with. If there are no insurance barriers, many retina specialists would prefer to choose an FDA-approved VEGF inhibitor because of the strong efficacy and safety data available with either aflibercept or ranibizumab. Currently, from the phase 3 clinical trials, aflibercept showed that it could be dosed every 2 months compared with monthly dosing of ranibizumab. That provides aflibercept with a slight advantage over ranibizumab for the treatment of wet age-related macular degeneration. In clinical practice, many retina specialists use a treat-and-extend regimen and feel that aflibercept because of its availability and evidence to be dosed every 2 months, it could potentially allow patients to be extended longer than eyes that would be treated with ranibizumab.
In eyes with wet AMD, retina specialists like myself start with intravitreal VEGF inhibitors. In clinical practice, sometimes we choose on-label treatments, such as ranibizumab or aflibercept, at the initiation of therapy. Or if medical insurance dictates, we may start with off-label bevacizumab. If as a clinician I don’t see an optimal response to the medicine that I first chose. If after 3 or 4 injections the patient’s vision has not improved, then I will likely switch to another agent that’s FDA approved. Many clinicians who let’s say start with intravitreal bevacizumab, which is off-label, and don’t see a good response in their patient’s eye, will often switch to aflibercept, which is FDA approved for the treatment of wet age-related macular degeneration. We’ve seen evidence from published case reports that in some eyes the switching of these VEGF inhibitors can provide a beneficial effect.
When retina specialists monitor patients who are undergoing VEGF inhibition therapy for their wet age-related macular degeneration, we look at a couple of parameters. First, we look at visual acuity and how they respond over time to the therapy. In addition, we look at retinal imaging with OCT, which is optical coherence tomography scanning. We use the constellation of the data we get from the clinical exam, the visual acuity, and the OCT imaging to give us an idea if the patient is responding. Usually, after a series of at least 3 injections, most patients will have some sort of response to their VEGF inhibitors. We’ll see an improvement in vision, or a reduction in swelling on the OCT scan. If we don’t see this improvement, then perhaps the patient needs to be switched to another intravitreal VEGF inhibitor. We’ve seen through clinical data that VEGF inhibitors do have differences. And that some VEGF inhibitors may have a more potent or durable effect compared with others.
In wet age-related macular degeneration, bevacizumab which is used off-label, is also a very commonly used medicine for the treatment of this ocular disease. The data for bevacizumab has shown that it’s very efficacious and safe but that it does need to be dosed quite frequently because of its ocular half-life. In many clinical cases, because of insurance issues and step therapy, we have to use bevacizumab as the first-line agent for eyes with wet age-related macular degeneration. If these patients don’t have a good response to bevacizumab after 3 or 4 injections—that is, their vision does not improve significantly, or the retinal edema and swelling does not improve on OCT imaging—then most of these patients will likely be switched to an FDA-approved therapy such as aflibercept or even ranibizumab.
Transcript edited for clarity