REGENXBIO Inc. (RGNX) Earnings Call Transcript & Summary

Good afternoon, everyone. My name is Gena Wang. I'm SMid-cap biotech analyst at Barclays. Welcome to Barclays 27th Global Healthcare Conference. It's my great pleasure to introduce our next presenting company, REGENXBIO. With me on the stage, we have Curran Simpson, President and Chief Executive Officer. Also, we have Steve Pakola, the Chief Medical Officer. So maybe I don't know if you guys wanted to give a quick overview before we dive into the questions.

Sure. This is a super exciting year for us. Following all the great execution of last year, we're excited this year for milestones, one of which is imminent, which is the completion of filing for our first BLA for RGX-121, which is intended for Hunter syndrome. And sort of coupled with that time line, we're also thrilled to talk about the closing of the deal with Nippon Shinyaku for the commercial partnership that we've developed with them. So a lot of really interesting updates on 121. Our Duchenne program, which is really in focus this year is actively recruiting Steve's team out pushing hard on enrollment for the pivotal study, which we're excited to have started late last year. And through the course of this year, we'll be giving out additional updates on not just safety and microdystrophin levels, but now venturing more into the functional outcomes for the patients, which we've been really excited to begin reporting last November. And then earlier this year, we talked and issued a press release jointly with AbbVie about our retina program, which we're thrilled to be planning for a diabetic retinopathy study using our suprachoroidal delivery method. And on top of that, this year, intend to close enrollment on ATMOSPHERE and ASCENT, which are the 2 large global studies that are being conducted for sub-retinal. So it's just an exciting year. All of the work we've done over the last, I think, 15 years of the history of the company, culminating into some of these major events for late-stage programs.

That's great. So maybe I'll start with the DMD program. I think for the Phase II update, I think the previous guidance was first half, so late first half, so I assume second quarter, the data update. So maybe any additional color regarding the number of patients and type of data you will be presenting and a follow-up?

Sure. So you'll recall in November, we had exciting initial data, both robust and high consistent microdystrophin expression at both dose levels. And importantly, that included high expression levels even in 8 and older patients. And we had our initial functional data that was supporting that we're seeing those expression levels lead to functional improvements at both dose levels. And at that point, we had 12-month data for the first dose level 1 patients, the 3 patients, and we had 2 patients with 9-month data. Our philosophy has been to wait until at least 9 months so that you have any potential impact of initial immune suppression and steroids out of the system so that you really know whether you're seeing a treatment effect or not. So I think what you can anticipate this half of the year is that we'll have more patients at dose level 2, where we have the microdystrophin levels. And we'll also have those 9-month dose level 2 patients out to 12 months. They won't necessarily be at exactly the same time point. We want to have the ability to give an update on additional microdystrophin levels and then also have more patients that have reached these different milestones. So another aspect is even in the dose level 1 patients, they've gotten through 12 months. Before too long, we'll have through 18-month data. So we're really reaching a pretty good inflection point in terms of a lot of patients with microdystrophin levels across an age range and also more and longer functional data outcomes, which is really what the clinicians want to see. They really like the microdystrophin levels, and they want to see that translate into functional benefit. Another key aspect for us is, as you know, there is no approved gene therapy for under 4 years old. And we have a cohort -- we have the only cohort in trials in the U.S. that's looking at under 4, so 1- to 3-year-old patients. So we announced start of that cohort. So when we give the microdystrophin update, we'll include the initial data that we have from that cohort. So we'll be able to extend the microdystrophin data that we already have from 4 years to 12 years, but also be able to start to have data in the under 4-year-old age group.

So the second quarter update, should we see the patients less than 4 years old, the biomarker data?

Yes.

Good. How many should we expect?

I think it's likely that we'd have one when we first announce. It all depends on the timing of when the data actually comes out. And we'll -- we have an earnings update, obviously, tomorrow where we can update guidance.

And along the way, I think you'll see enrollment updates from us. And I think one thing that I do want to convey is we're not just focused only on the enrolment and on the data outputs, but also on pulling forward all of the BLA-enabling activities. One thing that's really exciting is that we're starting our process validation runs this year for the future BLA submission. And that material, the first batch we make as part of process validation would be eligible for commercial sale. So it's really marking the beginning of our build for inventory for a potential launch in 2027.

Okay. And then maybe going back to the functional data, and you do have a wide range of patient age, right? So maybe what kind of functional data you will be sharing with us?

Sure. So I think you can look for the same measures that we've already presented on. So the usual suspects, so NSAA, but we'll also look at the traditional time-to-function tests like time to stand, 10-meter walk run, time to climb. So I think that you can think of that not trifecta, what's more than that, the cortex of endpoints. And we've seen very good results across those, even the NSAA, which has been beat up quite a lot since the Elevidys data didn't really show much of an effect on NSAA even once you got above the age of 4 to 5, but we've been seeing pretty encouraging results there at both dose levels. So we're excited to see if with more patients, we can confirm that, but also see consistency over time.

And maybe -- I know you will not comment on the competitor data, but in a way, we did see, say, solid show pretty impressive protein expression, right, the 3 patients like all above 100%. And so maybe from your perspective, do you think that like what could be the key differentiating there? If we just look at the nominal protein expression level, yours looks a little bit lower. But what we are missing or what should we look at when we look at the data?

Sure. So I think one aspect is a lot of us in the field think of a certain threshold effect where if you have more than 10% microdystrophin expression, that's when you would anticipate that you'll see a translation into a phenotypic event. So the key factors are, can you get substantial microdystrophin levels? And can it be consistent? Because even with the approved agent, you see on a mean basis, a reasonable microdystrophin level, but it's quite variable from 0 to 150% increase. But then what does that mean? There are some patients that you'll treat who have no increase in microdystrophin. So I think it's going to take more patients than the 3 to really understand what kind of variability exists. And I think the other factor we know is, well, what's the potency pound for pound or on a molar basis of how much you get in there and how durable that will actually be, which depends a lot on the construct. And Solid has their view on inclusion of the NNOS component. We certainly are very excited about our C-terminal domain that we include because that's actually within the Becker dystrophin construct. So that gives us already clinical evidence to believe that this is a microdystrophin that for whatever percent expression you have that, that can translate. And we've actually also -- I think we're the only ones who have ever done this. We've shown in preclinical studies with the MDx-recognized mouse model for DMD that 202 microdystrophin with the C-terminal domain leads to a better functional outcome traditionally measured in this model than the same construct without C-terminal domain. So when you look at that epidemiologic consideration in terms of Becker and then also that aspect of actually pre-clinically demonstrating that, we feel we're positioned very well for this. And I think also the other aspect is we've actually shown the microdystrophin levels in older boys. And no one's really shown what we've shown, whether approved or any experimental agent having these types of robust microdystrophin levels even in older boys with very diseased fibrotic muscle.

Okay. Very helpful. So -- and I do want to make a comment that younger than 4 years old when we did our DMD doctor panel, the doctor actually highlighted that why it's so meaningful because he actually felt frustrated that when it's 4 or 5 years old, it's already have the symptom and then you think that the benefit could be -- should be earlier than that. And so you are the only one doing that down all the way to 1 year old. So he actually highlighted that that will be one important differentiating factor there.

Yes. Time is muscle. And I think with increasing newborn screening, that's going to become even more of a demand in the field.

Right. So maybe for the BLA submission and what kind of data package now you also may have a less than 4-year-old data? And then regarding the safety, but of course, different modality, right, I think it was avidity with exon skipping is slightly different, but FDA did say wanted 25 to 30 patient safety, and I think it's over 12 months as a safety package for accelerated approval, like 30-plus, 30-something patients. So in your case, did the FDA say anything the follow-up time minimal in order to be sufficient for the safety package?

Yes. So just circling back, we had an end of Phase II meeting with FDA last summer. And then post that meeting, provided them with our pivotal protocol, and Steve can cover some of the detail around that. But in terms of the safety, database, 30 patients was what we prescribed in the protocol itself, and that was part of the review for FDA. So we feel confident that an end of 30 for the pivotal study is sufficient. Do you want to talk about time frames on safety assessments?

Sure. So for the efficacy under accelerated approval, we, of course, just need the 3-month time frame. I think an important aspect is with the patients we've already been discussing that we've been enrolling, if we consider completing enrollment in the second half of this year that we've already discussed and having primary endpoint readout early next year, we're going to have a lot of patients that are well over a year. I've mentioned some patients that are going to already be out 18 months very soon. So we feel very good about the sample size, but also having a robust number of patients that are out a longer time frame. On your aspect of the under 4, so with 30 patients, we aren't required to have some set number at each of these different buckets of ages, if you will. But we certainly plan to have a reasonable number in 1 dose. 3, 4 to 7 and 8 and older. And from the demand that we're seeing in the patients' families that are coming into the funnel, we're seeing a nice mix. So we think we're going to be in a good position to really support a broad label of and over.

And on safety, we're also able to give a 120-day safety update post the initial filing. So there will be ample opportunity to, I think, provide a comprehensive view.

Okay. Very helpful. So maybe switching gears to the 314 program, the wet AMD, sub-retinal, that will be 2026 data, right? So maybe any thoughts on the 2 data potential outcome and then the next step? I understand AbbVie took over mainly is in their hand. I don't know whatever you can comment, that would be helpful.

I'll let Steve comment on the trial design and outcomes. But we're still conducting the enrollment. We guided to completion of that this year, which is really exciting. And I think one of the strengths of the top line data and then subsequently filing the BLA. This will be a large data set, almost 1,200 patients. And that's where AbbVie having, I think, 700 people in their regulatory group will be really, really important to turn that as quickly as we can as we get close to filing. But maybe you want to speak to the potential outcomes?

Sure. So we have ATMOSPHERE and ASCENT, 2 non-inferiority 1-year-endpoints on the traditional best corrected visual acuity. One study is against monthly Lucentis and the other is against the active comparator EYLEA, loading doses plus the standard every other month dosing. So the concept here, of course, we got to show safety and show non-inferiority. And I think a key aspect here is that non-inferiority in a tightly controlled trial setting where you know the control arm is getting the doses that they're supposed to be getting, both because they are more compliant patients in general, and they're in a very tight protocol that if you can show non-inferiority in that setting, that's going to translate to actual superiority in the real world because we know in the real world, patients are simply not getting the injections they need, and they're actually going on to go blind. So that's why for us and AbbVie, it's clear that the value proposition isn't just decreasing the treatment burden. It's by doing that and having sustained anti-VEGF activity that you can actually have better visual outcomes for these patients.

And I think on ASCENT, we're excited that we are now recruiting in Europe as well as part of AbbVie's strategy to globalize the program. So I think since the partnership and now the evolution to where we are today, increased the robustness of the study and increased the global outlook for the program itself, which is really exciting.

Okay. Very good. And the diabetic retinopathy, the suprachoroidal delivery part, maybe any updated thoughts, Phase III trial design and the status moving forward?

Sure. So we're very excited that we had a successful end-of-Phase II meeting late last year as we had guided to the fact that we were going to have that meeting. And given that successful meeting, we and AbbVie were happy to announce at the beginning of this year, advancing plans for pivotal development to start this year. We haven't given specific details, but I think this is such a well-trodden regulatory path, fortunately, because of prior repeat anti-VEGF agents like Lucentis and EYLEA that have gotten the indication treatment for diabetic retinopathy. Interestingly, those are not being taken up by the community. I think less than 1% of patients are actually being treated because the treatment burden, repeat injections is never going to be an option for this patient population. So what you need is one-time in-office treatment, which we can provide to really take on this indication. And that's why we and AbbVie are excited about this, not only the big unmet need, but the clear regulatory path. So fortunately, there's a validated diabetic retinopathy severity scale where if you can show better outcomes on that than a negative control, in our case, a sham control, at 1 year, the standard endpoint time point, you can get approval. And that's a lot of derisking because you know not only the design that's accepted, but you also have a lot of confidence in what's seen without treatment. We know that patients who don't get treated do not magically get better, and they only inexorably advance in diabetic retinopathy. So we feel confident and AbbVie feel confident in designing such a study. But those are the basic design elements, superiority against no treatment, in our case, sham injection.

And I do want to say from investor perspective, it seems very easy beta thesis for them to push back for the eye indication with the gene therapy always good standard of care, nobody will use it. So I know it's a long journey. How do you review this thesis? I know when AbbVie and a drug approval launch, then that's the time you see this is the revenue, how much we can generate. But before that, what kind of messaging you can communicate with the investor to tell them you are wrong?

I think for diabetic retinopathy, it's very straightforward. In this case, it's an in-office procedure. The safety data to date has been tremendous, which is what's been a problem with a lot of other gene therapy studies is the therapeutic window is quite narrow, and matching efficacy and safety has been a challenge. But I think for DR in particular, it addresses the unmet need as opposed to that. Now for sub-retinal, Steve, you might want to comment on what do you hear from investigators that are part of our study around the promise of the drug.

Sure. And even before the investigators, AbbVie's confidence in this, not just in the U.S., but globally, I think, is important validation that a company with AbbVie's global experience and also experience specifically within eye care, I think, is a strong support. So it's not just REGENXBIO saying this. But we say this precisely for the reason Curran is alluding to that we speak to all our investigators. We speak to other thought leaders in the space. And if you're seeing a patient after a procedure, not need any injections for 4 years or more, which is what some of our investigators have seen in our Phase II study, and you also see patients who have not been, let's call them, complete responders, but they even have fewer injections. Certainly, the patients are excited about that, and that makes the investigators excited about that. We have a fellow eye study that we've reported on where we show fortunately in this bilateral disease that we can treat both eyes. And I can say, being on the ground and hearing the investigators that the patients want to have their fellow eye treated if they actually have active disease in their fellow eye. So I think the other aspect is this is a massive multibillion-dollar space. So are all patients going to be amenable to sub-retinal administration? No. But our investigators and also thought leaders say, well, maybe 20% to 25% of my patients would I consider this treatment? Well, a fraction of that is a pretty sizable proportion of the market. So we see a very good value proposition here.

I think the statistic that was developed was something like 1 in 9 patients have lost to follow-up. And many times, some of the investigators come to our meetings and articulate they know who those patients will be. They're moving to Florida, et cetera, and they're not going to be staying on a constant regimen. So I think maybe one way to look at it as well is people think of it as we're trying to cut into an existing market where there's a very established practice, but the market is growing and potentially doubling in the next 5 years or so. Retina centers are already overburdened. So I think our alternative is a way for them to manage growth as well. And so I think that's maybe what AbbVie sees in it and certainly what we see in the indication.

Good. And last 1 minute, maybe quickly on MPS II. Is that on track? Like should we expect potential approval in the 3Q?

Yes. Everything is absolutely on track with the filing of the third module. It's just literally going through some final QC, and we expect to submit imminently. And the partnership with NS Pharma has been kicked off. We're through the Hart-Scott-Rodino review. So that deal is closed. So we have a clear line of sight to a PDUFA date in the fall and really excited about the program. And I think it's exciting for those of us that have worked on this program for more than 10 years to see for any company, it's great to file your first BLA, I think. But also, we were able to get a really huge short-term win on cash as part of the deal with the upfront milestone and then preserved a lot of the long-term value of the program as well through that. So we feel great about where we are with Hunter.

Great. Well, thank you very much, and maybe look forward to tomorrow's earnings call.

Absolutely. Thank you.

Thank you. Bye-bye.