Good morning, ladies and gentlemen, and welcome to the Abeona conference call phase 3 clinical trial. At this time, all participants have been placed on a listen-only mode, and the floor will be open for questions and comments after the presentation. It is now my pleasure to turn the floor over to your host, Mr. Greg Gin, VP of Investor Relations and Corporate Communications. Greg, over to you.
Thank you, Jenny. Good morning, everyone. I would like to welcome and thank everyone for joining us for our conference call to review the positive top-line results from our pivotal phase 3 VITAL study of EB-101 in patients with recessive dystrophic epidermolysis bullosa or RDEB. The press release announcing the top-line results is available on our website at www.abeonatherapeutics.com. Before we begin, I want to remind everyone that the presentation may contain projections and forward-looking statements regarding future events. Forward-looking statements are made pursuant to the safe harbor provisions of the Federal Securities laws. These forward-looking statements are based on current expectations and are subject to change, and actual results may differ materially from those expressed or implied in the forward-looking statements.
Various factors that could cause actual results to differ include, but are not limited to, those identified under the section entitled Risk Factors in the company's annual report on Form 10-K and other periodic reports filed by the company with the Securities and Exchange Commission. These documents are available on our website at www.abeonatherapeutics.com. On the call today is Vish Seshadri, Chief Executive Officer of Abeona, who will provide some opening remarks and background on RDEB. Also with us today is Dr. Igor Grachev, Head of Clinical Development at Abeona, who will review the VITAL study results. Vish will then discuss key takeaways and next steps for the EB-101 program. After the prepared remarks, we will host the Q&A session, where we will also be joined by Dr. Brian Kevany, Chief Technical Officer and Head of Research, Joseph Vazzano, Chief Financial Officer, and Amanda Truesdale, our Head of Biostatistics.
With that said, I will now turn the call over to our CEO, Vish Seshadri. Vish.
Thank you, Greg. Good morning, everybody, and thank you for joining us this morning. We issued two press releases this morning. The first release announcing the top-line results from our phase 3 VITAL study of EB-101, and the second release announcing a $35 million PIPE private placement financing. Before getting into VITAL top-line results, I want to first thank the new and existing institutional investors who participated in the transaction and for their belief in and support of Abeona. With today's financing transaction, we have strengthened our cash balance and extended our expected cash runway to the third quarter of 2024, well beyond the anticipated timing for potential BLA approval of EB-101. Now let's discuss the first piece of news we announced.
We are excited about the positive outcome from our EB-101 phase 3 VITAL study, the only pivotal study targeting large chronic wounds in RDEB, with pain as a co-primary endpoint in addition to healing. The results are frankly outstanding, and today is an exciting day for the RDEB community and the entire team at Abeona. Before we get into the phase 3 study, let's first remember why we are here. Patients with RDEB currently have no approved treatments. One of the many clinical manifestations of the disease is large chronic wounds which have limited ability to self-heal, hardest to treat, and cause intense pain, especially during periodic wound dressing changes. The unique value proposition of EB-101, our autologous engineered cell therapy, is its ability to both heal and reduce pain in large chronic wounds with durable benefits.
While we're here today to talk about the VITAL study results that further demonstrate EB-101's benefits, I first want to note that the long-term follow-up data from our phase 1/2a study were recently published in the Orphanet Journal of Rare Diseases. The data showed that large chronic RDEB wounds treated with EB-101 had considerable wound healing with mean 5.9 years of follow-up and long-term symptomatic relief, including pain reduction. Based on the phase 1/2a results and the positive VITAL results that we will be sharing today, we believe EB-101 has the potential to be a one-time therapy for these large chronic RDEB wounds. I'll start with a brief overview of the VITAL findings and then hand it over to Dr. Igor Grachev, our Head of Clinical Development, to review the data in more detail.
VITAL met both of its co-primary efficacy endpoints, demonstrating statistically significant, clinically meaningful improvement in wound healing and pain reduction in large chronic RDEB wounds. EB-101 significantly improved wound healing versus control across all levels of healing at six months. For the first co-primary endpoint, a proportion of wounds achieving 50% or greater wound healing, EB-101 showed 81% healing versus 16% in control wound, with a highly statistically significant P value of P less than 0.0001. EB-101 also achieved statistically significant improvements versus control at six months in addition, additional endpoints, namely greater than or equal to 75% wound healing rate and complete wound healing rate, which Dr. Igor Grachev will discuss in more detail.
VITAL's second co-primary endpoint is patient-reported pain reduction, which differentiates VITAL from any other pivotal study in RDEB. A patient's pain perception and scoring for a particular wound can often be influenced by changes in adjacent regions within the same anatomical area and create a halo effect. Therefore, a signal for pain improvement has to be pronounced enough to cut through that noise and yield a statistically significant result. For the co-primary endpoint of pain reduction, EB-101 treated wounds achieved a 3.07 mean reduction from baseline in pain associated with wound dressing changes using the Wong-Baker FACES Scale at six months versus a 0.9 mean pain reduction in control of untreated wounds. The P value for pain endpoint was 0.002. Additionally, no serious treatment-related adverse events were reported, which is consistent with a favorable safety profile in past clinical trial experience with EB-101.
Let's now turn to understanding a little more about RDEB and the disease burden. RDEB is a rare genetic skin disorder caused by mutations in collagen VII, leading to defects in the anchoring fibrils that attach the outer and inner layers of the skin. Patients with RDEB face a lifelong struggle with fragile skin that easily tears and blisters, with most patients developing large wounds that remain unhealed, often covering a significant proportion of their body. Since there are no approved treatments that address the underlying protein deficiency, patients rely solely on palliative measures that include expensive and time-consuming wound care involving parents or caregivers spending hours daily with wound dressing changes. Care of these open wounds is very painful, and patients often turn to opioids to help make it more tolerable. Large chronic RDEB wounds can lead to skin infection, inflammation, and squamous cell carcinoma.
The picture on the slide shows a large chronic wound spanning the back and shoulders. One can imagine the extreme pain associated with such wounds and the difficulty in carrying out routine daily activities. EB-101 works by restoring normal functioning collagen VII to keratinocytes and their progenitors delivered through engineered keratinocyte sheet that transplants onto open wounds that allow for durable healing and pain reduction. To review the VITAL data in detail, I now turn the presentation over to Dr. Igor Grachev, our Head of Clinical Development. Igor?
Thank you, Vish. Good morning, everyone. It's great to be with you on such a happy day for RDEB community. I will start with the trial design. VITAL was designed to investigate the efficacy, safety, and tolerability of EB-101 in approximately 36 large chronic wound pairs in 10-15 patients with minimum age of six years. Our study was randomized and controlled. Each patient had a minimum two large chronic wounds selected, with each randomized treated wound being paired with untreated control wound similar in size, years that the wound remained chronically open, and anatomic location to the extent possible with the same patient. In VITAL, we defined large chronic wounds as wounds that have greater than 20 sq cm of surface area and remain open for a minimum of six months. We align with the FDA on the study endpoints and statistical analysis plan.
Given that EB-101 is targeting large chronic wounds, remember, the hardest to treat wounds that remain open for years because they cannot self-heal. We align on the co-primary endpoint of greater than or equal to 50% wound healing, and its secondary, second co-primary endpoint of pain reduction as additional measure of clinical benefits. Specifically, the co-primary endpoint were proportion of RDEB wound size with a greater than or equal to 50% healing from baseline, comparing randomized treated with matched untreated control wound size at the six-month time point, as determined by direct investigator assessment. Pain reduction associated with wound dressing change, assessed by the mean difference in score of the Wong-Baker FACES Scale between randomized treated and matched untreated control wounds at six-month time point as reported by the patient.
VITAL allowed for additional wounds to be treated with EB-101, but not paired with a control wound due to lack of feasibility of randomization. These non-randomized wounds were not included in the primary efficacy analysis. Let's continue by reviewing the baseline characteristics. Overall, we treated a total of 43 randomized large chronic wounds in 11 patients. Patient age ranged from 6 years to 40 years, with a mean age of 22.5 years. Each of the 43 randomized and treated wounds was paired with untreated control wound within the same patient. An additional 14 non-randomized wounds were also treated with EB-101. Baseline wound characteristics underscore the large size and severe pain associated with wounds included in VITAL and includes the following.
Mean body surface area of randomized wounds treated with EB-101 per patient was 156 square centimeters, with range of 80-200 square centimeters. To clarify, every treated wound of 40 square centimeters exactly the size of the graft. For large wound area that exceeds 40 square centimeters, multiple grafts could be applied in a quilt-like fashion, in which case the area covered by each graft is considered as a distinct wound. If a wound area was less than 40 square centimeters, debridement was required to prepare the wound bed to fit the graft. On the contrary, control wounds were not debrided. Mean wound duration of randomized treated wounds, that is, years that the wound had remained chronically open, was 6.2 years. The control untreated wound had very similar wound duration.
Overall, the randomized treated and control untreated wound also had similar pain severity at baseline. Pain is assessed during dressing change, the time at which pain is most intense, using Wong-Baker FACES Pain Rating Scale of 0 to 10. At baseline, the mean pain severity score of randomized treated wounds was 5.12. At baseline, the untreated control wounds had a mean pain severity score of 4.38. Furthermore, the median pain in both groups were identical. Before turning to the data, I will share a note about our conservative approach in handling missing data for primary analysis. For 50% or greater wound healing rate analysis, wounds with missing wound healing data are considered as not healed for the primary analysis. Four randomized wound pairs from one patient fall into this category.
For pain reduction analysis, wound pair with missing pain data at baseline are excluded from the primary analysis. One randomized wound pair falls into this category. Let's turn to those data now. Let's start with the core primary endpoints, where significantly more wounds achieved 50% or better wound healing and showed significant pain reduction after EB-101 treatment. As shown on the left, 81% of randomized treated wounds achieved 50% or greater wound healing from baseline by investigator assessment at six months, as compared to 16% of randomized untreated control wounds, and the difference met statistical significance with P value less than 0.0001.
For the second primary endpoint of pain reduction, as shown on the right, a greater reduction from baseline in pain associated with wound dressing changes was observed in EB-101 treated wounds at six months compared to the untreated control wounds. Mean pain reduction was 3.07 for EB-101 treated wounds, compared with 0.9 for the control untreated wounds. The mean pairwise difference across patients in pain reduction was 2.23, with P = 0.0002 and sample size of 42 wound pairs in 11 patients.
In addition to meeting the primary endpoint in post-hoc analysis of EB-101 treated severe wounds defined as baseline pain score of six or greater, including randomized and non-randomized, total of 27 wounds, and a mean pain reduction from baseline at six months was 5.7, observed as compared to the mean pain reduction of 3.51 for all treated randomized and non-randomized wounds for which pain was evaluated. It’s a total of 53 wounds. The pain reduction appears to be very clinically meaningful. Turning now to the association between wound healing and pain reduction. This study was not powered to show statistical significance for correlation between wound healing and pain reduction. However, a trend of greater magnitude in pain reduction was observed with greater wound healing in VITAL.
As you can see, wounds achieving 50% or greater wound healing had 3.37 mean pain reduction from baseline at six months, as compared to 3.86 mean pain reduction and 5.14 mean pain reduction for wounds with 75% or greater healing and complete healing, respectively. Turning to other healing endpoints in VITAL, we also measured the proportion of wounds showing 75% or greater wound healing and complete wound healing. As you can see, 65% of randomized treated wounds achieved 75% or greater wound healing from baseline by investigator assessment at six months, as compared to 7% of randomized untreated control wounds. This difference met statistical significance with P-value less than 0.0001.
For complete healing, we also met statistical significance with P value of 0.016, with 16% of randomized treated wounds achieving complete wound healing from baseline by investigator assessment at six months, as compared to 0% of randomized untreated controlled wounds. Let me mention a few points about stringent criteria applied to score wounds as complete healing. Completely healed was defined as complete re-epithelialization with no drainage nor erosion. There had to be no major crusting as judged by investigator to score as a completely healed wound. In VITAL, with the presence of any crusting, the investigator was unable to verify underlying epithelial formation, which led to the wound being scored as not having met complete healing. I will share some photographic examples of the following slides.
Note that the untreated control wounds did not meet complete healing, which appears to be hard to treat wound type. These are pictures of patients with large chronic wounds on the upper left thigh. On the far right, tattooed wounds were scored as 75% or greater healed, but not completely healed at week 24. You can see there appears to be some crusting, but the healing looks nearly complete to the naked eye. These are pictures of patients with large chronic wounds on the right medial and lateral scapula. B3 was treated with EB-101 and B4 was untreated control wounds. On the far right, B3 was scored as 75% or greater healed, but not completely healed at week 24. Again, you can see there appears to be some crusting, but the healing looks nearly complete to the naked eye.
Notably, you can see that before the untreated control wounds clearly has not achieved the same level of wound healing as EB-101 treated wound. On this slide, these are pictures of VITAL patients with large chronic wounds on the upper trunk. Both the wounds show before and E9 were treated with EB-101. On the far right, B4 was scored as 75% or greater healed, but not 100% at week 24, and E9 was scored as completely healed at week 24. Both wounds appear to have similar level of healing. Except for the small red dot on B4, it appeared to be very close to completely healed. Now, let's review safety and tolerability. EB-101 was shown to be safe and well tolerated, with no serious treatment-related adverse events observed in VITAL, consistent with past clinical trial experience.
There were no deaths or instances of positive replication-competent retrovirus results, and no systemic immunologic responses were reported during the study, as well as no squamous cell carcinoma at treatment site after application of EB-101. Two subjects reported at least one serious adverse event unrelated to EB-101. Four subjects reported related treatment emerging adverse events, including procedural pain, muscle spasm, and pruritus. Infections were observed in eight patients and were not related to EB-101. Wound-related treatment emerging adverse events were reported in 9 out of 100 wounds. With that, I will turn the presentation back over to Vish. Vish?
Thank you, Igor . To summarize, EB-101 has achieved statistically significant and clinically meaningful results across endpoints in VITAL, in particular for wound healing by investigator assessment at all healing levels versus control and pain reduction reported by patient versus control. In EB-101 treated wounds with severe baseline pain, we observed even more pronounced pain reduction. No serious treatment-related adverse events were observed, which is consistent with past clinical experience with EB-101. We plan to present results from the VITAL study, including further details with additional exploratory endpoints and the week 12 results at future medical meeting and in a peer-reviewed journal. The week 12 results are similar to week 24 results, achieving statistical significance for pain reduction and wound healing at all levels.
Based on the results in VITAL and the long-term follow-up data from our phase 1/2a study, we have conviction in the potential of EB-101 to deliver durable wound healing and pain reduction in large chronic RDEB wounds and improve patient quality of life. Remember, in our phase 1/2a study, we have seen evidence of multiyear wound healing and pain reduction after EB-101 treatment with a mean follow-up of 5.9 years and a maximum of eight years. With that, I would like to share our next steps in our development program. While we have previously gated some capital-intensive BLA-related activities, now that we have seen the VITAL data and given our other news release today about a capital raise, we plan to submit a Biologics License Application with the FDA in the second quarter of 2023.
Recall that EB-101 has been granted a rare pediatric disease designation, RPD in short, by the FDA. Concurrent with the BLA submission, we plan to submit the application for a priority review voucher or PRV, which can be used to receive an expedited review process of a subsequent marketing application for a different product or sold to another company. Based on the anticipated timing of BLA submission, we expect potential BLA approval in the first quarter of 2024. In terms of commercial launch, we have had prior discussions with multiple potential partners to commercialize EB-101. Now with the very strong data from VITAL, we are well positioned to realize EB-101's full value, either through a commercial partnership or by launching EB-101 ourselves. We're excited to execute on these plans.
Before we open the call for questions, I would like to thank everyone who's contributed to what you've heard today. We are grateful to the patients, their families, caregivers, and the patient advocacy groups for their support of the study, and are also thankful for the clinical investigators, Dr. Jean Tang and Dr. Karen Wiss, and their study site personnel and the entire Abeona team who collectively contributed to this milestone achievement. With that, I turn the call back over to Jenny for the Q&A session. Jenny?
Thank you very much. Ladies and gentlemen, the floor is now open for questions. If you have any questions or comments, please press star one on your phone at this time. We ask that while posing your question, you please pick up your handset if listening on a speaker phone to provide optimum sound quality. Please hold while we poll for questions. Thank you. Your first question is coming from Maury Raycroft of Jefferies. Maury, your line is open.
Hi. Good morning. Many congrats on the results today. Great data overall. Wondering if you can talk a little bit more about data beyond the six-month primary endpoint time point and comment on durability and whether it's consistent with your phase 1, 2 experience so far. As a follow-up question, I was hoping you could talk more about the graft success and failure rate and talk about next steps for manufacturing.
Thank you and good morning, Maury. Your first question about data beyond six months, the short answer is, at this point, we have not analyzed that because you may remember that, we had accrued nearly six patients, in the last 5.5 months of, study accruals. We don't have sufficient follow-up to look at those results. It will be forthcoming, in, updates next year for the 1-year follow-up and thereafter. Your second question about, manufacturing, it's, a broad question. I'll start with, the fact about the clinical trial supply. As you know, all the patients in VITAL had their grafts manufactured in our Cleveland site, and every patient that provided biopsy received grafts.
In terms of next steps, in terms of CMC, we had a Type B meeting with the FDA earlier this year and aligned on what exactly a validation protocol looks like, and we are triggering some of those activities now to be ready for the module 3 of the BLA by the second quarter of next year. As I had mentioned earlier, we wanted to gate resource-intensive BLA activities on the CMC side after learning the VITAL results, so we're triggering it now and the team is working literally on steroids, figuratively, but we are still getting to second quarter of 2024 for the BLA submission itself.
Got it. Maybe one other question just on partnering. If you can talk a little bit more on where you're at with those discussions and the type of partner that you're looking for to move forward with?
Thanks for that question, Maury. In fact, where we start is that the VITAL study results are in the best-case scenario that we could have hoped for. Clearly, partnering discussions even prior to reviewing the data have been ongoing with some potential partners but it makes us, you know, rethink our strategy while we would continue those conversations. Since the data are just two or three days old since we pulled together from VITAL, these are very fresh discussions that are going on, so I don't have anything definitive.
In general, we're looking to trigger launch preparation activities in the first quarter of 2023 and any partnering would be dependent on gaining, you know, an optimal valuation of this asset that we would like to retain. If we have a suitable partner that has a presence in the specialty derm space and recognizes the value that we've created, then that's the direction we will go. Just wanted to reiterate that we're also capable of launching it ourselves, so we are keeping both options open to see what types of deal terms we may land on.
Got it. Makes sense. Congrats again, and thanks for taking my questions.
Thank you, Maury.
Thank you very much. Your next question is coming from Kristen Kluska of Cantor Fitzgerald. Kristin, please ask your question.
Hi. Good morning. Thanks for taking my questions, and congratulations on the data and the great work that you've done for a much deserving community here. While EB-101 clearly had strong effects broadly, did you notice any trends in terms of time to heal or healing patterns related to location on the body or other variables or factors that you think could help you when working with physicians in a potential commercial setting?
Thanks for that question, Kristen. The time to heal, as I had mentioned qualitatively that the week 12 results, which is the first time point of assessment from patient follow-up, we have not yet fully you know disclosed those data. We see that all the endpoints, whether it's healing at different levels of thresholds or pain, look very similar to what we are seeing in the six-month endpoint. If you take the phase 1/2A results as a reference, this is a therapy where grafts are applied, so the closure is immediate and we're seeing very early or rapid onset of the clinical benefit. The week 12 results, while I can tell you qualitatively look very similar, we will be sharing the exact metrics.
They appear nearly identical, I would say, but the numbers will be out in a scientific congress probably in the first or second quarter of 2023.
Thank you for that. Of the patients you saw in this trial, could you talk about generally how many wounds they presented with in general and how you believe they could fit the profile of those receiving EB-101? I guess translating to commercial opportunity, how are you thinking about the average number of the EB-101 treatment cycles that they need to go through?
That's a fantastic question, and we've been thinking a lot about that as well. We have some initial pointers. There's been a lot of wound characterization data in the public domain and literature that our estimation is that on average, the body surface area covered with these types of difficult to treat large chronic wounds is approximately 960 centimeters squared per patient with RDEB. In one go, if you look at the last five or six manufacturing runs, we're able to manufacture north of let's say 10 grafts. Each graft is a credit card size, which is like 40 centimeters squared. It covers approximately half of all the large chronic wounds in one round of manufacturing.
Our estimation is that per patient we anticipate treating two rounds to address all large chronic wounds in the body surface area where we would deem EB-101 as a suitable therapy. Of course, we're not looking at flexion areas like joints. It's hard to put grafts on joints because of you know the movement and uptake there. That's generally what the treatment opportunity looks like. Of course, if you look at epidemiology, published literature estimates around 3,850, nearly 4,000, prevalent pool of RDEB patients that already currently exist in the U.S. If you look at the incidence pool every year, the estimation is about 90 per million births.
That puts us somewhere in the ballpark of about 300-400 patients entering the pool every year. That gives you an idea of how many patients with RDEB are there. Even if you put an estimation of the proportion of patients that have these large and chronic wounds and will want to access EB-101, we're currently with rough estimates, we're estimating that there's gonna be in the order of 2,000-2,500 patients that would want this therapy. If you say average 2 cycles of treatment per patient, you can look at the number of treatment opportunities. The other component of the commercial opportunity here is also the pricing.
I think with this kind of pain control that we've seen from VITAL and also the durability of benefits from our phase 1/2A study, we will have to now, you know, re-look at what a potential price point for a one and done therapy with years of clinical benefit with, you know, pain control could command. That's work TBD, but we're happy where we may land just based on how strong the data look right now.
Okay, thanks. Last question for me. I've often heard the phrase that RDEB is the worst disease you've never heard of. Given that, you know, we're talking about an indication where there was absolutely no treatments available and now there could be something to the market, how do you think that narrative has changed, and how do you expect it to potentially change in the near term?
Yeah, I mean, the phrase that the worst disease that you've never heard of, I couldn't agree more. It's more for the rest of the community that are not inflicted with the disease, right? There's no disease as rare to the families that are actually going through that disease, right? We're very thankful that there's a very strong patient advocacy community here, you know, and there's hunger in the market for effective therapies to be approved. We're looking at, even though it's a rare disease, a patient community that is very well informed and very well connected with the advocacy network.
We would be working closely with them, you know, to make sure that, you know, patients are aware of what technological advances are under investigation right now and what could potentially come out there. That's exactly, you know, what we're already doing. You probably saw the press release with Brett's quote there as well. These patients have been waiting for years for any approved therapy, and there's really nothing yet. It's great news for patients that we're starting to see data emerge from these therapies.
What we're hearing from the physician side is that they need more than two, three, four therapies to tackle the multitude of problems that these patients face because it's not just a small recurrent wound or these large chronic wounds or esophageal strictures that the patients have to you know endure or corneal abrasion, squamous cell carcinomas. There's so many different clinical manifestations of this disease that they're gonna need more than two or three therapies in the course of the disease. That probably you know is true for every RDEB patient out there.
Great. Thank you so much, and congratulations again, Vish.
Thank you, Kristen.
Thank you very much. Once again, ladies and gentlemen, if there are any remaining questions or comments, please press star one on your phone. Your next question is coming from Jim Molloy of Alliance Global Partners. Jim, please ask your question.
Hey, guys. Congrats on a great data. Thanks for taking my question. I was wondering for the docs, if you could talk a little bit about sort of the standard of care now in the space. I mean, has this become the de facto standard of care, again, assuming approval, you know, something that seems very possible with the data. How does this sort of compare to Krystal's VYJUVEK gel, like Krystal?
Yeah. Thank you for the question, Jim. Standard of care today is gauze, right? Patients are bandaged in gauze. They spend three times a week redressing those wounds, and there's intense pain associated with wound redressing. Each dressing episode, for many patients, can exceed 5, 6 hours, and wound infections are often associated with open wounds, large open wounds, that are managed using antibiotics. Other than really gauze and antibiotics and some use of narcotics for pain control, there's really no therapeutic intervention in the market today. Because you brought up, you know, Krystal and VYJUVEK, we're hoping and rooting that VYJUVEK gets approved, because these patients need therapies that, you know, address the underlying disease.
For the dataset that VYJUVEK has published in the smaller wounds and some of the recurrent and chronic wounds, based on size, we think that, you know, we had an advisory board with physicians, asking how would you use. Basically the unanimous answer was, "We're gonna have to use both these therapies on almost every RDEB patient in the course of their disease, because you're gonna have some wounds that look like large and chronic, like an entire trunk or a upper thigh or, you know, such large areas where you need immediate pain control, and that's where EB-101 is gonna be used.
There's gonna be wounds that will be in flexion areas or, you know, where it's not feasible to apply a graft and, you know, you're gonna need a gel kind of therapy. When I talk about the long-term benefits, I think the other difference is a chronic therapy versus a, you know, a one and done kind of treatment. In our treatment, we use retroviral transduction to deliver a copy of the COL7A1 gene to the host genome, right?
This is propagated within the patient. Once you apply the autologous graft, you see years of sustenance of the benefits from the phase 1/2A study, and our hypothesis is that there is some kind of retention even with you know cell turnover or whatever that the gene of interest may be propagated. Whereas if you use an episomal maintained vector, over time you're gonna see dilution, so that's gonna need more you know chronic application of therapy. They're addressing different types of problems as well as slightly different you know value propositions.
We're trying to bypass the natural, you know, the steps of nature, where you're putting the gene into the wound area, and you're waiting for that to be taken up by themselves, and they have to express the gene and replicate and things like that. Instead, we are just looking to, you know, bypass a couple of steps and just provide the grafts directly to the patient. Where there's immediate need for pain control, this may be a, you know, desired approach. There is clearly some differentiation of how these therapies are gonna be administered, and that's what we're hearing from both the patient community as well as, you know, the KOLs that see a lot of these types of patients. I hope I addressed your question, Jim.
No, great. Thank you very much for that. And Vish, could you talk a little bit about the pros and cons or what would you be looking for? I know you mentioned you're looking for, you know, especially pharma in the derm space. But can you talk about what would you like to see in a partnership where that would make you say, "All right, we're doing that," versus self-launch or what a self-launch would look like, the size of the reps? And then in the EU as well, what's the thinking there?
First off, this is a niche rare disease indication which will not have. It's not like launching a diabetes drug where I need 200 reps across the country doing a lot of sales and marketing. The launch, you know, the heavy lifting in the launch is gonna be really based on onboarding sites. There's gonna be centers of excellence where we're gonna contract out how this therapy can be applied. It's not something that you would launch with, you know, 100 hospitals in the country. With, you know, with centers of excellence, like we already have Stanford and UMass on the opposite coasts.
With additional three or four more centers, we think we can have a pretty good radius of catch of what patients will need to access with minimum travel those centers that we will need to onboard and you know contract with to be able to administer EB-101 therapy. This is a launch that's gonna require patient services and delivery more than a sales and marketing push. I think that's a distinction I would bring up because we're not looking for a large pharma partnership like you know the big Pfizer here. We're looking for a partnership where a company may have that presence already in dealing with maybe burn units or specialty derms already with other products which are similar in nature.
If such synergies are achieved, we could see value in a partnership. Of course, given the profile that we've learned from VITAL, we would like to retain, you know, a sizable portion of the NPV for this asset. That's also in the back of our mind as we think through what type of partnership deals that, you know, we would entertain here.
Okay, thanks. My last question is sort of the tail end of the press release. It's thought there's a note about still seeing the data up to eight years in the phase 1/2a. Can you talk a little bit about what you're seeing at up to eight years and the durability of the effect?
Yeah. Eight years is the patient with the most mature follow-up. The mean follow-up for that study is about six years, 5.9, I think is the exact number there. Overall, yes. In one of the slides that we just presented today, I just wanted to remind people that we're seeing a pretty good durability across, I think 96 months was the last time point for the most mature follow-up, but we're seeing most of the wounds that did heal show that kind of durability over the years. Short answer is yes, and the pain scores are pretty well correlated. This was published in the Orphanet Journal of Rare Diseases just a week or two ago.
We're seeing in that there was some correlation analysis between how much of wound healing and pain reduction was there at both the six-month time point as well as five years. It's encouraging to see that even at five years, those wounds that were healed at the 50% threshold showed 67% of them showed freedom from pain. That was a binary answer. Pain is yes or no answer, but still, to see that kind of correlation, majority of these healed wounds are pain-free and you know, almost every unhealed wound had pain. That kind of correlation existed even at the end of five years. That's basically telling us that you know, we have a very consistent result there.
Great. Thank you. Thank you for the questions.
Thank you, Jim.
Thank you very much. There appear to be no further questions in the queue. I will now hand back over to Vish for any closing remarks.
Thank you, Jenny. In closing, I want to thank our shareholders and other stakeholders who have listened to this call. We will talk to you again very soon. Thanks for joining us in today's webcast. Bye-bye.
Thank you, ladies and gentlemen. That does conclude today's conference call. You may disconnect your phone lines at this time, and have a wonderful day. Thank you for your participation.