The following transcript has been edited for clarity.
Diana V. Do, MD: Hi, I’m Diana V. Do, MD, at Retinal Physician. Today I’m joined by one of my friends and leaders in retina, Peter Kaiser, MD. Thanks, Peter, for coming.
Peter Kaiser, MD: Thanks, Diana, for having us.
Dr. Do: Tell me about OTX-TKI (Axpaxli; Ocular Therapeutix). A lot of exciting news about this new drug and tyrosine kinase inhibitor (TKI). What’s the latest we should know about?
Dr. Kaiser: OTX-TKI is a TKI that is a pan-VEGF, pan-PDGF inhibitor combined with our proprietary hydrogel platform. What that means is it allows for sustained release. We now think it works maybe 9 to 12 months. We have a positive phase 3 clinical program. Based on that, we are now working with the US Food and Drug Administration (FDA) for our new drug application (NDA).
Dr. Do: That’s exciting. And I know in the phase 3 program there was a positive outcome where OTX-TKI was superior to aflibercept. How is the FDA looking at 1 clinical trial compared to traditional 2 phase 3 clinical trials?
Dr. Kaiser: That’s a great question. When the FDA tried to do a modernization act a few years back, what they wanted to do is make it easier and more streamlined to get drugs approved. And so they set down some rules and guidelines for what would be considered for a single-trial submission and what would require more than one: the usual 2-trial submission. One of the key features is high statistical significance; so in other words, very unlikely that the result was due to chance. That’s one of the reasons why they do 2 studies, because that way you reduce the likelihood that it was actually due to chance, number one. Number two, you have to have evidence to support it. So this confirmatory evidence is the key part of the submission package.
Last year, for instance, of the NDAs that were approved, over 60% were actually single-trial submissions. So this is not a new thing for the FDA. It’s actually something that many have used, we just haven’t seen it as much in ophthalmology. Now there are a few companies, for instance, the PEACHTREE study for Xipere (Bausch+Lomb), that was a single-study approval. Lytenava (bevacizumab-vikg; Outlook Therapeutics) was based on 1 positive clinical study recently. So it’s not that we’re the first, but it’s just using the guidance of the FDA.
What sets that apart is really early and very consistent and basically constant interactions with the FDA. With the SOL-1 program, we got a special protocol agreement (SPA), which right off the bat means the FDA at least agrees to this clinical study design and makes it more likely, if your results are positive, that they’ll accept it. It’s not automatic, of course. We had a high statistical significance, so we immediately went to the FDA, had a Type C meeting—which is in person, where you discuss whether this is a possibility—and we’re excited to say that just recently, about a week or two ago, we had what’s called a pre-NDA meeting. And at that meeting you go over with the FDA, what are you going to submit? So for instance, are you submitting 300 patients for safety with anti-VEGF agents? Are you submitting 100 patients with endothelial cell counts? These are all things that you have to ask the FDA—can you submit the NDA? What is required? And then when you agree, then you can submit the NDA. So the good news is that meeting was very successful, very positive, and we’re still on track to file by the end of this year.
Dr. Do: It’s very exciting. It's always good to have new innovation and new therapeutic options for our patients. So we look forward to more news in the near future.
Dr. Kaiser: Fingers crossed. Thank you, Diana. RP