Welcome everyone to the Fourth Quarter and Year End 2024 REGENXBIO Earnings Conference Call. At this time, all participants are in a listen-only mode. To ask a question during the session, you'll need to press star one one on your telephone. To withdraw your question, please press star one one again. Please be advised that today's conference is being recorded. At this time, I'd like to turn the conference over to Patrick Christmas, Chief Legal Officer of REGENXBIO.

Good afternoon, and thank you for joining us today. Earlier this afternoon, REGENXBIO released financial and operating results for the fourth quarter and year ended December 31, 2024. The press release is available on our website at www.regenxbio.com. Today's conference call will include forward-looking statements regarding our financial outlook, in addition to regulatory and product development plans. These forward-looking statements are subject to risks and uncertainties that may cause actual results to differ from those forecasted and can be identified by words such as expect, plan, will, may, anticipate, believe, should, intend, and other words of similar meaning. Any such forward-looking statements are not guarantees of future performance and involve certain risks and uncertainties. These risks are described in the risk factors in the management's discussion and analysis section of REGENXBIO's annual report on Form 10-Ks for the full year ended December 31, 2024, and comparable risk factor sections over REGENXBIO's quarterly reports on Form 10-Q, which are on file with the Securities and Exchange Commission and available on the SEC's website. Any information we provide on this conference call is provided only as of the date of this call, March 13, 2025, we undertake no obligation to update any forward-looking statements we may make on this call on account of new information, future events, or otherwise. Please be advised that today's call is being recorded and webcast. In addition, any unaudited or pro forma financial information that may be provided is preliminary and does not report to project financial positions or operating results of the company. Actual results may differ materially. I'll now turn the call to Curran Simpson, President and CEO of REGENXBIO. Curran?

Thank you, Patrick. Thank you everyone for joining us today. 2025 is a transformational year for REGENXBIO. We are off to an exciting start. We've submitted our first BLA and expect our first FDA approval in the fourth quarter for RGX-121, which is our treatment for boys with Hunter syndrome. We will build on this momentum by advancing our diabetic retinopathy program to the pivotal stage this year, then head into 2026 with potential BLA filings for large opportunities including RGX-202 for Duchenne muscular dystrophy, and ABBV-RGX-314 for wet AMD. We are in a strong position as we prepare to launch multiple first or best-in-class gene therapies and have robust commercial capabilities and global partners. This is all with a view to sustainable profitability and is the result of fifteen plus years of gene therapy leadership. On today's call, I will review our recent business highlights and outline a vision for what we believe will be catalyst-rich years ahead. Then our chief medical officer, Dr. Steve Pakola, will summarize our clinical progress before handing it over to Mitchell Chan, Chief Financial Officer. Mitch will provide an overview of our financial results and share the many potential non-dilutive capital sources ahead. I'll then make some closing remarks before we open for Q&A. Starting with our recent exciting news in MPS, we are thrilled to have completed the submission of the BLA for RGX-121 or chlamydia lamparvivac, under the accelerated approval pathway and partnered with Nippon Shinyaku for both of our MPS programs. This partnership marries our collective strengths, REGENXBIO's development and manufacturing expertise, with Nippon's experience in successfully commercializing rare disease products. Our teams are planning for potential approval of RGX-121 for MPS II in Q4 2025 and are working diligently to prepare for the commercial launch. Along with enabling access…

Thank you, Curran. I'll start with RGX-202, a potential one-time gene therapy for the treatment of Duchenne. RGX-202 is the only microdystrophin construct to include the C-terminal domain making it closest to naturally occurring dystrophin. In preclinical studies, microdystrophin with the CT domain was shown to better protect the muscle from contraction-induced damage associated with muscle breakdown in Duchenne. In November, we announced the initiation of the pivotal phase of the AFFINITY Duchenne trial evaluating 202 at a dose of 2E14 genome copies per kilogram in approximately thirty ambulatory patients aged one and older. We also recorded positive safety and efficacy data from the phase one/two portion of the study. The data disclosed in November included positive functional outcomes from the first five participants in the Phase one/two portion at nine and twelve months. We also shared microdystrophin and other compelling biomarker data from eleven patients. In summary, the results showed 202 recipients exceeded external natural history control and established benchmarks for clinical outcomes. Specifically, we observed functional improvements in all patients treated with dose level one and dose level two at twelve and nine months respectively. Consistent robust expression transduction and localization of our differentiated 202 microdystrophin in the muscle and also a favorable safety profile observed at both dose levels. There were no serious adverse events or AEs of special interest, which is truly outstanding in the landscape of Duchenne Gene Therapy. As we've discussed, we've taken a thorough proactive approach to safety. Based on input and partnership with treating physicians and the patient community, as well as learnings from the field at large. Our immune suppression regimen including a short course of eclizumab combined with our novel microdystrophin and leading product purity levels may be contributing to this positive safety profile. These positive clinical results further strengthen…

Thank you, Steve. REGENXBIO ended the quarter on December 31, 2024, with cash, cash equivalents, and marketable securities of $245 million compared to $314 million as of December 31, 2023. The decrease was primarily driven by cash used to fund operating activities during the twelve months ended December 31, 2024, partially offset by $131 million in net proceeds received from an upsized public offering of common stock and pre-funded warrants completed in March 2024. R&D expenses were $209 million for the year ended December 31, 2024, compared to $232 million in 2023. The decrease was primarily attributable to decreases in headcount and preclinical activities. We expect the balance in cash, cash equivalents, and marketable securities of $245 million as of December 31, 2024, to fund our operations into the second half of 2026. This cash runway guidance is based on the company's current operational plans and excludes the impact of any future potential commercial revenue associated with RGX-121. If we include additional non-dilutive financing, we expect the cash runway to potentially extend meaningfully beyond 2026. For instance, some examples of our non-dilutive financing options include our expected DR milestone payment from AbbVie, development milestone payments from Nippon Shinyaku, conversion of our Zolgensma royalty income, and the potential monetization of our priority review voucher on RGX-121 if approved. Collectively, we have many non-dilutive financing optionality that could extend our cash runway well beyond the second half of 2026. In summary, we feel we are in a strong financial position as we near. With that, I will turn the call back to Curran to provide final thoughts.

Thanks, Mitch. As you heard today, there's strong momentum across our pipeline as we advance towards key milestones. To recap, we have officially submitted our first BLA and closed an important partnership with Nippon Shinyaku for our MPS programs. We look forward to a potential FDA approval of RGX-121 this year. The pivotal study of RGX-202 is moving rapidly and we believe remains well-positioned to potentially serve as the next and preferred gene therapy in Duchenne muscular dystrophy. We plan to share additional positive biomarker data later this month followed by updated functional data. And with enrollment nearly halfway through, we expect to complete enrollment of the pivotal study this year and share top-line data in the first half of 2026. Our partnership with AbbVie is advancing towards multiple large global commercial opportunities. We expect to complete enrollment of two global pivotal trials for subretinal wet AMD and are working with AbbVie on a pivotal study in diabetic retinopathy in 2025. As we look towards the next nine months and beyond, we are well-positioned to deliver on multiple late-stage opportunities. Our programs are demonstrating beneficial differentiation against standard of care and available treatments. Each of our assets represents one-time treatments with the potential to transform the trajectory and management of disease for patients in need of new and better options. We look forward to sharing additional updates on our plans and achieving our critical milestones this year. With that, thanks for everyone for your time today. I'll turn the call over for questions. Operator?

Withdraw your question. Our first question comes from the line of Judah Frommer with Morgan Stanley. Judah, your line may be on mute.

Hi. Can you hear me now? Yep. Thanks for choosing question, Bryce. Hi. Congrats on the progress here. Just one on cash runway and one clinical question. So I was hoping maybe you could delve a little deeper into the components of non-dilutive financing that are still available. And maybe you could give us kind of some internal insights into probabilities around realizing those. We do get questions around the PRV and then anything that could get in the way of the AbbVie milestone coming through for DR. And then just on the clinical side, another question we've been getting just expectations around potentially going to an ad com for 202 once you have the full dataset. Thanks.

Yes. Thank you, Judah, for the question. Regarding non-dilutive options, as I kind of mentioned, it really comes in three different flavors. The first one is the DR milestone that we expect to receive in the second half of this year. That really is gated upon the first patient dose, and Steve and Curran could definitely speak to the clinical program timings and so forth. But that's really the, you know, potential risk to it is, it's more of a timing issue than anything else. Because our expectation is that they will move forward. Regarding the PRV, I think the question here is when do we receive a potential regulatory approval. Upon regulatory approval, that's when we're eligible to receive our, you know, priority review voucher we could then choose to monetize it at our discretion. So I think that's, you know, I'll say it's more of a regulatory approval risk than anything else, which do not expect to have anyways at this moment in time. And the other non-dilutive financing option really is on the potential of Zolgensma royalties stream that may revert back to us. Once we hit the HGR cap, of $300 million, that royalty stream does revert back to us. Again, it's hard to predict future revenues from Zolgensma given that it is promoted by a third party, Novartis here. But once that we reach the cap, that revenue stream will revert back to us forward to the revenue stream.

Hi, Judah. It's Curran. I can talk a little bit about just the PRV and probabilities of success. And I think the fact that we've had a pre-BLA meeting with FDA written reviewed the pivotal data really helps in terms of de-risk. They've seen our approach. And while, of course, it's a regulatory review and you know, that has risk associated with it like any. We feel like we're in a really good place particularly because I think in over time, MPS II and therapies like ours have been referred to as perfect fits for an accelerated approval pathway. So I do expect this to be a high probability event in terms of receiving both an approval and the PRV. And, you know, that's in line with all the FDA. I'll let Steve comment a bit on DR, but I think, you know, the events that are occurring for DR now are really just regulatory discussion with AbbVie in the lead in terms of conducting those meetings. We talked last fall about the end of phase two meeting with FDA and related that that meeting was very positive in terms of our approach. And we've also discussed that they're also seeking regulatory advice ex-US, and that's an ongoing process. But we feel like two key things, the data's strong, and so far the feedback's strong. Again, pointing towards a positive movement towards the DR pivotal this year. And Steve, I don't know if you have anything to add to that.

Sure. Hi. Judah. Yeah. I think as Curran mentioned, we're very happy with the end of phase two meeting with the FDA. AbbVie's always been very interested in global advancement and really getting access to 314 globally. That's one of the reasons we struck the deal with AbbVie. So not surprisingly, for a global diabetic retinopathy plan, they do wanna get EMA and feedback from Japan. So those are some of the aspects that we wanna tidy up those ends before we know, give any more details on the plan. But I think, fortunately, we have the benefit of precedent in treatment of diabetic retinopathy to know what to expect in terms of a regulatory path here. So we feel this is pretty darn de-risked based on our regulatory discussions today. You also, Judah, had a question on adcom. Probability, which I believe is probably related to 121 since we announced completion of the BLA submission. We don't know. You know, it's not the kind of thing we can say with a hundred percent certainty either way. We, as of now, don't see a significant issue anywhere that would suggest one is needed. If one comes our way, we'll be ready for it. So I think with any development program at this stage, you plan in case you may need it. If we have one we'd be very confident with the discussions because of the compelling data we have and the different stakeholders that could be a part of getting across that benefit and the benefit-risk for the product. But as of now, we don't know.

Thanks.

Our next question comes from the line of Gena Wang with Barclays.

Thank you for taking my questions. I apologize if this question already being asked. My phone got dropped, so I missed the previous question. So I have two questions. One is regarding the NDA update. Just wondering how many patient data from one to three-year-old should we expect to see? And also, you know, giving the younger patient age, should we expect to see higher protein expression? And related questions, any thoughts regarding lower age to zero, given, I think, a solid mention they were. Start a cohort between zero and eighteen. And then my second question is regarding the altitude, DME cohort. Just wondering what will be the timing of data update? And then in terms of also number of patients and type of data you will share with us.

Great. I'll take the first one, and then I'll let Steve answer the second one. So we're planning to update at MDA likely one patient in the one to four cohort in terms of their microdystrophin value. And I would suggest based on the emerging database that we're gaining on age versus microdystrophin that it's a fair expectation to expect a high number in terms of microdystrophin level. But, obviously, we'll save that specific for the conference itself. But we're seeing a general trend that the younger patients will have higher microdystrophin numbers, both in our study and other studies that we're able to see in the public domain.

Yeah. Hi. Hi, Gena. Thanks for the question. So Altitude, our diabetic retinopathy study, where we've already shown very solid data in terms of diabetic retinopathy. Patients without DME, and that's why we're so excited with AbbVie to go into pivotal. You referred to the DME cohort, which we currently have enrolling. Enrollment is progressing quite nicely. We haven't given any guidance on when we would read out but it's safe to say that when we do to your question of what you could look for, you could look for the typical things that we've looked for in a wet AMD population but with different reference points of what you'd expect. So in DME, you care about visual acuity, and you also care about disease activity assessed by retinal thickness on OCT. And, of course, the third part of triad is can you achieve good disease control and good visual acuity with a reduction in the need for injections. So basically treatment burden. So we would report on all three of those as well as safety.

Thank you.

Our next question comes from the line of Mani Foroohar with Leerink.

Hey, guys. You have Ryan on for Mani. Thanks for taking our question. So maybe just two. Can you talk about what you're seeing in terms of pace of enrollment for the DMD pivotal trial and whether you, you know, expect this to accelerate as the year goes on as you activate new sites and share more data in the first half of the year. And then maybe just on the younger patient enrollment within DMD, have you moved on to enrolling those patients in the pivotal trial yet, or are you still enrolling that separate cohort from the phase one, two trial?

Thanks. Yeah. I think it's safe to say that we're seeing really encouraging enrollment in terms of the Duchenne study. And I think to the second part of and we know that from the screening logs and what we're seeing at sites as sites are activated that you know, there's a significant number of there's significant amount of interest in a significant number of patients that are going through screening. And second part is, yes, we do expect it to accelerate primarily because we're increasingly adding sites to the study. So you know, the overall productivity of the study will just continue. So it'll be a nonlinear enrollment curve, if you will. And we're super optimistic about how certainly meeting our guidance, which will be concluding enrollment this year, but we're aiming to exceed that guidance by beating that timeline significantly.

The other interesting aspect, Ryan, is it's not just increased sites, which certainly is gonna help as we bring more sites on board, but we really saw a lot of interest after our November functional data update. We've heard from patient advocacy and investigators that there's a lot of families that have been waiting on the sidelines for a next-gen gene therapy as long as they could see some functional data. So I think having the nine and twelve month data has really bolstered our case across our clinic. So I think we're in a good shape there. You also asked about the younger patients, the one to three-year-old age group. We look forward to providing the initial data in terms of microdystrophin in that age range. And we do now, by the way, are getting back to Gena's question that younger, we have seen with other programs that you have higher microdystrophin levels. And I think one of the massive unmet needs is in the older patients where you don't see with other programs high microdystrophin levels. So we're really excited about that. But we really want to treat broadly across the entire age range, and that's why we're enrolling not just the traditional four and up, but actually one year old and up. Your question, any patients that come in now in that are one and above, are gonna account for Pivotal. So we are very excited to enroll across the age range that one to three years, four to seven, and also at eight and older.

And we're particularly interested in that cohort because as you know, there's no approved therapy for patients in the one to four age category. So that's a key element of our pivotal plan. And we'll these patients will be included in that.

Thanks, guys.

Our next question comes from the line of Luca Issi with RBC Capital Markets.

Oh, great. Thanks so much for taking our questions. This is Lisa on for Luca. Just on the DMD program, can you remind us if you are measuring cardiac endpoints like left ventricular injection infraction or cardiac biomarkers like troponin I as part of the affinity study. And if so, could these be a meaningful way to differentiate your program further from elovitis? And I have one question on wet AMD. On the subretinal study, I'm just curious if you are considering maybe cutting the enrollment a bit too short in order to accelerate the readout timeline. We know the wet AMD space is very competitive, and there are also two long-acting TKI studies that are also anticipated to read out in that same 2026 time frame. And as we know, from Vabysmal's launch being first to market, does matter. So any color here on DMD or those subretinal pivotals, that would be appreciated. Thanks so much.

Great. Thanks. I think I'll let Steve comment certainly on the retina discussion. But in terms of cardiac, Steve can describe what we're measuring in the clinic. But certainly from our preclinical data, when we looked at biodistribution in our early preclinical studies, we certainly have reason to expect good biodistribution not just to the peripheral muscle, but to the heart and to the lung. Section. So that's represented well in studies that we did preclinically like the treadmill test for MDX mice. So I think in terms of do we expect our study to differentiate on that, of course, that'll come down to what we consider for cardiac little bit longer-term outcomes. We don't expect to see dramatic cardiac improvement in a four or five-year-old, but over time, that's something will certainly be monitored. Maybe I'll let Steve cover how we're doing that.

Sure. Hi, Lisa. Yeah. The reasons Curran mentioned, we feel very positive about the potential to have a benefit for Duchenne children, not just based on skeletal muscle, but also the cardiac manifestations. But I think one context to give is that these decreases or deterioration in cardiac function happen at an older age, then the typical functional assessments that we look at in the younger age group. So it's really as the boys advance into the teen years that you see the unfortunate cardiac deterioration. So that's one of the reasons we're so excited that we're seeing very high and consistent microdystrophin expression in these older boys. So that also bolsters our confidence. So how can we look at this? Certainly, ejection fraction, as you mentioned, is one of the measures. You can look with echo, which isn't as accurate and sensitive as looking with MRI. So we do incorporate both of these, so we're gonna have the ability to look at that. We do also look at troponin levels. So again, I think the key aspect is you're it's not gonna be really meaningful to look at these while patient's cardiac function is normal. So in the traditional age groups up to eight, for example, and really, it's gonna be more once the patients get above ten where you start to see abnormal ejection fractions, for example, where you can then monitor a stability and more or less preventing worsening in these boys. So the fact that we have patients already enrolled that are older, I think we're in a better position to monitor this over a long time, and we have patients already out. Nine and twelve months and further as we go out further. But it's really something that takes more time for sure than a…

One thing I would add too, just we are certainly cognizant of timing and moving as quickly as we can to a BLA filing. And that's one reason that AbbVie, for example, will be doing the preparation and filing of the BLA. They have upwards of seven hundred people in their regulatory group. And so these are it's a very large study, and we're gonna rely on AbbVie who has I think, a great track record of speed to BLA from top-line data. So that's something to follow in the next year with we're with you in terms of going as fast as possible, but we'll as Steve mentioned, we wanna do it the right way.

Alright. Thanks so much for taking the question.

Thanks.

Our next question comes from the line of Annabel Samimy with Stifel.

Hi. Thanks for taking my questions. Just following on the regulatory discussions for DR. Are there any specific key areas of difference between the US and the OUS regulators that we should be thinking about? I know that the pathway is pretty clear for the US. I'm curious about OUS. And then on DMD, for the upcoming not the muscular dystrophy association, but the one where you're gonna be disclosing functional data. Will we be seeing just a follow-up from patients we've already you've already disclosed, or will we see new patients of the eleven that had already been treated? And then finally, for DMD, the fifty percent enrollment, can I just can you just clarify that this includes whether this includes new patients that were enrolled into the pivotal, or does it also include the patients from the phase one, two study? Thanks.

Great. Yeah. I'll take the MD first, and then I think we'll let Steve comment on he's part of the joint development team with AbbVie that's conducting these regulatory meetings and can comment. For Duchenne, the data that we're speaking to around functional updates later this first half will be all of the above. So patients that we've already discussed at dose level two that were at nine months moving out to twelve. New patients that have not previously been reported in the dose level two phase one/two study, likely at nine months. And then also long-term data on the dose level one patients that'll be out at least to eighteen months depending on the timing. Specific timing of the update. So that's what we're planning for. We don't have a specific number for new patients yet, but as you know, from the past, there's seven patients total in that cohort. So we're just incrementally adding. Hopefully, meaningful updates, not patient by patient, enriching that dataset as we go. I think to the question of does the pivotal enrollment include new patients? The answer is yes. We have new patients that have been enrolled since we announced that we were recruiting for the pivotal trial. And also some of the patients that were dosed actually, the majority of them that were dosed in the phase one, two study would also be eligible as part of the pivotal data set. And just recall that's an n of thirty that we're driving for to complete that study.

Hi, Annabel. I'll take the first question now on diabetic retinopathy and the pivotal plan. As you mentioned, fortunately, there's a clear path from precedent of getting an indication for treatment of diabetic retinopathy from drugs like Lucentis and Eylea. Where what's been accepted and what's still accepted is use of the diabetic retinopathy severity scale. Which has been clinically validated to predict bad outcomes for patients with diabetic retinopathy. And we know the path is there, but these drugs are not being used because of the significant treatment burden that's needed to keep the disease at bay. So that's important because that means it's still open the ability to use a negative control. So for example, in our case, the potential to use a sham control arm where we know that those patients don't magically get better. And in fact, they on average, get worse. So it allows us to power a study with the traditional to look for a difference in active treatment compared to a negative control arm. There isn't that known precedent for Europe. So that's one of the reasons we wanna work with the EMA and also in Japan. We think there's a very solid case for use of the diabetic retinopathy severity scale. In fact, the more years that go by and the more studies that are done, we think that case gets stronger. And so we look forward to in the future giving an update on discussions that we've had with regulators around the world.

Thank you.

Our next question comes from the line of Brian Skorney with Baird. Brian, you may be on mute.

You're right. All for me now. Thanks for taking the question, everyone. You've now submitted BLA for Hunter with Zebra, had discussions going to federal program for DMD and planning a program for diabetic retinopathy. Know, we get a lot of questions about continuity at suit fever. Given the change of guard at HHS and FDA, and I don't really know anyone who probably had more than see with Zebra that than you guys over the last couple of months. So just wondering, you know, if Celia went into the part a couple of weeks ago, if you could give us a sense as to how up to date you're this discussions with Zebra and OTPR, and if you're seeing significant change within the review division, they also type of products, and how much that could potentially impact future gene therapy reviews.

Yeah. I think our general comment is from our perspective, it's business as usual in terms of submissions that we're making. We're on a pretty frequent basis providing amendments to protocols, amendments to INDs, and those are you know, we're getting questions back and forth on certain things. So we're really not seeing a significant difference either in timing of responses or availability of the teams. And I think we were encouraged by some of the comments especially on the rare disease side around accelerated approval from Macarrie and, you know, just the overall sentiment. So to date, I think we feel number one, that we've got really good connections and really good previous dialogue with the review team. The review team seems stable from what we can tell from those interactions. And, therefore, we don't see any change in sort of the risk profile of our pending BLA now, and ongoing discussions for Duchenne.

And then maybe if I can ask a follow-up on DMD, now that you're about fifty percent enrolled into the 202 pivotal, you give us any flavor as to how screening kind of goes? Are you seeing any particular favoritism by age or characteristics in terms of patients looking to screen? I mean, in particular, I'm wondering if, like, the availability of 11us and s's data, but if it's sort of what I think, you know, our four to five-year-old favoring coming in. To be screened for gene therapy or because the data's strongest for a lot of SDC sort of in that age group, do you see patients coming outside of that four to five-year-old on a demand basis?

Yeah. I'll generally comment, and then I'll let Steve maybe discuss because he does see the screening logs in more detail than I do. I mean, one of the reasons that we wanted to point to nearly half enrollment of the pivotal study is that in addition to that, our screening logs and patient testing for neutralizing antibodies, it's a significant number of people of patients being screened, and that just points to the strong interest we see from the patient community. And from the Duchenne patient advocacy groups as well that are supporting us. Steve, I don't know if you wanna comment. Are we seeing any difference in terms of the ages or is it just a broad distribution?

I'd say it's a broad distribution, Brian. I think families across the age range have certainly different needs or different ways they'd look at evaluating different treatment options. I think that's where our differentiation comes into play. So I think certainly, the microdystrophin levels that we're seeing, that's clear. Differentiation in the eight and older. As you mentioned, the four to seven and particularly the four to five is really the subset of patients where there's the most evidence for alevitus. I think one aspect that is a differentiator across the spectrum is safety. So safety first, that's certainly how investigators think about it, and that's how patient families, of course, think about it. So we believe with various aspects of our program, both our proactive immune suppression transient approach. Our high purity levels that are very differentiating. And overall, what we're seeing is very good safety. We have seen no SAEs, no AEs of special interest, so that includes no LFT elevations, no thrombocytopenia. And these are findings that have been seen in other programs. And with the levituz, I think upwards of forty percent have LFT elevation. So that's a clear differentiator that we think is important across the age range. Certainly, in the three and under, bucket, those are patients who do not have access to approved gene therapy in the US. One of the aspects we're excited about our program is some of the not just microdystrophin expression, but also vector genome copies per cell that we're actually seeing, which are much higher than has been reported by any other program. So we think that gives added confidence when you think of that younger age group where there still be some muscle cell division. So in short, in summary, we see good differentiation aspects that are compelling for doctors and patient families to consider. And that's why we're confident we're gonna get a widespread which is a goal given the broad patient population. We wanna have safety and efficacy.

I think particularly if you think about it, ninety-five percent of the prevalent market is still available. For these studies. So I think that plus the focus on next-generation therapies is really helping with enrollment. So we're excited where we are this early in the year. And I can guarantee we're pushing to go as quickly as we can on all fronts for the BLA submission.

Great. Thank you.

Our next question comes from the line of Paul Choi with Goldman Sachs.

Thank you. Good afternoon and thanks for taking our question. I want to ask on Affinity and how you're thinking about your post-trial or post-approval commitments and just your thoughts on the, you know, sort of requirements, I guess, down the road for confirmatory study or other regulatory requirements. I'm just your thoughts there. And second, you know, based on the data you're seeing to date, in the ambulatory population, I wanted to see if you know, what's the current appetite to potentially explore 202 in a non-ambulatory population at some point even if it's an exploratory study? Just your thoughts there would be great. Thank you for taking our questions.

Great. Thanks. I think in terms of confirmatory study, we're gonna have that discussion in more detail with FDA in terms of what's required. But I think in general, we intend to continue to enroll post-enrollment of our pivotal n equals thirty dataset towards the end of completing a confirmatory study as quickly as possible. And we'll have further discussions with FDA in our pre-BLA meeting about what exactly that will mean. I think and the second question just remind me.

So on non-ambulatory.

Yeah. We're certainly considering strongly conducting studies in non-ambulatory patients. But right now, not at the expense of going as fast as possible for the ambulatory one and older patients that we're conducting as part of our clinical studies now. So it is definitely a consideration given the size of the prevalent market there. But we just don't want to use our sites for that purpose at this point given that we want to close out our pivotal study as quickly as we can this year.

Given the excellent microdystrophin levels and also functional results that we're seeing in eight and above, including a twelve-year-old. It's an interesting dilemma, really. Like, Curran said, we gotta focus on the population, for our pivotal, but more and more, once we showed that data, patient advocacy are asking about non-ambulatory because it's quite logical given the results we've seen. So it's something we'll be looking at, but not acutely adding to the pivotal.

One thing I would add just to finish the question on planning for confirmatory study, we do have drug supply already prepared to cover both the pivotal study and a future confirmatory study based on some planning assumptions that we've made. So I think that's really important that we can seamlessly move into a confirmatory study with existing drug supply.

Our next question comes from the line of Ellie Merl with UBS.

Functional data. Specifically, what should we be looking for at this upcoming data update and both of this update, but then thinking longer term both from the pivotal study and then potential confirmatory. What do you think would be differentiating in terms of functional data? And then in terms of the pivotal study, I guess, how do you plan to analyze some of the functional data? Do you have any staff protocol for, say, doing a natural history comparison? And if so, is this something that you've discussed at all with the FDA? Thanks.

Great. Yeah. I'll cover just the general specifics of the functional updates, and then maybe I'll let Steve talk about the analysis of the data versus baseline. And the external match controls that we're doing. I think in terms of the near-term functional data, as I mentioned earlier, you should expect to see additional patients that were treated at dose level two in our phase one/two study. Will be specific about the number of patients more around when their visits occur and when the data is updated. We'll also report twelve-month data on patients that we previously reported. There were two at nine months in that release. And also we will update patients dosed at dose level one that were at twelve months who are now likely out to about eighteen months, maybe in maybe two years, on some longer-term data, but, of course, that's not at the pivotal dose. So it'll be just informational at that point. So that's what you should expect to see near term. And then over the course of the year, I would expect to see most of the data for all seven patients that were dosed at dose level two out to twelve months, but that'll be much later in the year.

And as far as what we'd see or what we'll look at, it'll be the usual suspects, Ellie, as far as time function test. So time to stand, ten-meter walk, run, time to climb. And NSAA, which traditionally has been viewed as less sensitive than the time function test. But, actually, in our November update, we saw encouraging results, not just on the time function test, but also on the NSAA. So we're excited to see if we can confirm those findings on longer follow-up on the existing patients and then increase the sample of patients at dose level two. What we see on those. We'll continue to look at this the way we've done in the past, which is not just in isolation, but compared to matched external natural history controls. So that's really important given disease trajectory is different depending on age and baseline severity. So we match on all those factors to give greater confidence in terms of whether individual patients' trajectory is positive or not. We have discussed this with the FDA, so this was certainly a part of the successful end of phase two meeting that we held before starting Pivotal. And we had no issues getting into the Pivotal design.

Thanks.

Our next question comes from the line of Sean McCutcheon with Raymond James.

Hey, guys. Thanks for the question. One for me on NPDR. Steve, to your point, we've seen some reticence from patients to receive anti-VEGF therapies due to that high burden or frequent injections. And you've shown some meaningful decreases in vision-threatening events up to twelve months in altitude at the higher dose. In line or better than the panorama study of Flovercept. What do you view as the treatment durability at which we could start to see more utilization in NPDR? And how do you view that as distinct for a gene therapy versus say, sustained release TKI? Thanks.

Sure. That's a great question, Sean. And I think that is the key observation that we've seen is that even though repeated anti-VEGF injections definitely work, it's just too much of a burden for patients and doctors to give injections indefinitely. Because once you stop giving the injections, the severity comes back. So you're basically signing patients up who are currently asymptomatic to get injections the rest of their life, basically. And that's really the barrier also to even longer durability TKIs. Since it's certainly better to only need an injection every six months or even every year, but if it's repeated injections, we see that as a major barrier. And that's why we and AbbVie are so excited about the DR indication because of suprachoroidal in-office one-time injection is really the way to address this massive unmet need and why we're excited with the data that you referred to where we've shown an eighty-nine percent reduction in vision-threatening complications at a year. So that really was the impetus for us in AbbVie accelerating the end of phase two planning now that we have the positive outcome of that study now we're both excited to advance into pivotal this year.

Thank you.

Our next question comes from the line of Alec Stranahan with Bank of America.

Hey, guys. Thanks for taking our questions. Maybe two from us. Both on DMD. Appreciate the updates on the pace of enrollment in Affinity Duchenne. I guess, how long after completion of enrollment do you think we could see data? Would twelve-week microdystrophin for the primary be enough? Maybe for the top line, or would you want to wait a bit longer for some of the other endpoints? And second, I'm sure you guys are tracking the evolving commercial market in DMD pretty closely. I guess maybe following up on a previous question, what's your expectation around the market dynamic in, say, a year or two when you're a bit closer to approval? Any updated thinking around, you know, current supply and the addressable market at launch would be great. Thank you.

In terms of the second question, I think I'll take first. I think one of the key aspects of our plan is that we think at least half of the prevalent market will still be available by 2027, which is what we're targeting for a potential approval. And if you look at the updated guidance now, we're pointing towards a mid-2026 BLA filing. So that could lead to a potential approval in early 2027, which I think is really important. And we're already planning how to address the market. We'll be making our first lot that are eligible for commercial sales starting this fall. And we have the capability with our in-house manufacturer significant number of doses that had a launch. So assuming we can establish a broad label, I would expect we're gonna be very aggressive commercially in 2027 to take a significant amount of the prevalent population in terms of market.

And then, Alec, as far as your first question about when would we have actual results that we could disclose. The twelve-week time point, that is our accelerated approval endpoint time point for microdystrophin. So that's a very significant step. So we certainly would be coming out with that data since that's really what's gonna drive actually going ahead with the BLA submission by mid next year already. So we'd also have safety at that time point as well. So I think that really puts us in a good position.

And I think if you think about what functional data would we have in hand at the time of filing, certainly, the full phase one/two dose level two cohort would be past twelve months at that point. And a good proportion of the patients treated in the pivotal study will have at least nine-month, if not twelve-month data. So we'll have a healthy level of functional data to accompany the primary endpoint of microdystrophin at the time of filing and probably be able to update that somewhat at the one hundred and twenty-day safety update as well.

Got it. Makes sense. Appreciate the color.

Our next question comes from Yi Chen with H. C. Wainwright.

Thank you for taking my question. Could you comment on Yifeng Shiyaku's sales team presence in the US? How many of them will be promoting RGX-121? And do you expect that any sales-related milestone could be triggered within twelve months of commercial launch? Thank you.

Didn't quite hear the first part. Could we repeat just the beginning of that? Question? I got the a little bit muffled.

The sales team presence of the Bon Secours in the US. How many of them will be promoting RGX-121? If it's approved?

Sales force that services their Duchenne launch, and we expect that majority of those that same team would be applied towards commercialization of RGX-121. You know, given the timeline now that we filed the BLA, we're pointing towards PDUFA date somewhere in Q4 of this year. And that would point to a launch either late this year or early next year, of course. And feel positive that the partnership with NS Pharma allows us to do that as rapidly as possible. Good alignment officially with them on site selection for commercial sale. There are dosing centers that we've worked with clinically that we feel are obvious choices that have also previously handled commercial products. So more to follow as we go through the review process on the BLA. In terms of achievement of sales milestones, the milestones there are some that could be realized in the first year of sale. They're sort of staggered throughout the growth of the product. We haven't commented previously on what proportion that might be of the $700 million total potential milestones, but some of those could be realized in the first or second year of launch.

Thank you. I'm showing no further questions in queue at this time. This concludes today's conference call. Thank you for participating. You may now disconnect.