The following transcript has been edited for clarity.
Diana V. Do, MD: Hi, today I’m with Wiley A. Chambers, MD, former leader at the US Food and Drug Administration. Dr. Chambers, during Clinical Trials at the Summit, we had some great panel discussions with you about the regulatory pathway of new therapies. First, can you clarify, do companies need to have one vs two phase 3 clinical trials in order to be considered for approval? And how do you look at safety and efficacy in these large-scale clinical trials?
Wiley A. Chambers, MD: So the law only requires 1 clinical trial, an adequate and well-controlled trial, with confirmatory evidence. The issue is, how do you get confirmatory evidence? And that frequently is easier to get with 2 trials than it is to get with just 1 trial. The other major component to this is, not only do you have to have efficacy, you have to have safety. And it’s rare in ophthalmology that we get enough safety patients in 1 trial. So the end result is, you really should plan for 2 trials.
Dr. Do: Thank you very much for that insight. Another hot topic is looking at treatments for earlier stages of age-related macular degeneration (AMD), specifically intermediate AMD. What are acceptable endpoints for clinical trials looking at intermediate AMD?
Dr. Chambers: So the endpoints for intermediate AMD are the same as they are for any other type of AMD, which means you’re still looking for improvement in visual function, because that’s what patients care about.
Dr. Do: And in terms of visual function, are we looking specifically at a number of letters of improvement?
Dr. Chambers: Yes. Unfortunately, or maybe fortunately, every state in the United States requires a certain level of visual acuity. And so it ties to your ability to independently live if you have improved or maintain your visual acuity. So that becomes a very big benefit to match the potential adverse events when the FDA looks at the product.
Dr. Do: Great. Thank you so much for your leadership and insight.
Dr. Chambers: You’re welcome. RP
