VECT - VectivBio Holding AG (VECT) Q4 2022 Earnings Call Transcript

2023-04-19 14:18:07 ET

VectivBio Holding AG (VECT)

Q4 2022 Earnings Conference Call

April 19, 2023, 08:00 AM ET

Company Participants

Patrick Malloy - SVP, IR

Luca Santarelli - CEO

Claudia D'Augusta - CFO

Omar Khwaja - Chief Medical Officer

Kevin Harris - Chief Commercial Officer

Conference Call Participants

Allison Bratzel - Piper Sandler

Tazeen Ahmad - Bank of America

Thomas Smith - SVB Securities

Patrick Dolezal - LifeSci Capital

Presentation

Operator

Welcome to the VectivBio's Fiscal Year 2022 Results Call. At this time, all participants are in a listen-only mode. After the speakers' presentation, there will be a question-and-answer session. [Operator Instructions] Please be advised that today's conference is being recorded.

I would now like to hand the conference over to your speaker today, Patrick Malloy, Senior Vice President, Investor Relations. Please go ahead.

Patrick Malloy

Thank you, and good morning, everyone. Welcome to today's call during which we will provide an update on the Company and review our financial results for the full-year ended December 31, 2022. Earlier this morning we issued a press release summarizing our financial results and progress across the Company, which is available on our website.

I'd like to remind everyone that during today's discussion, we will make statements about our future expectations, plans, and prospects that constitute forward-looking statements for the purposes of the Safe Harbor provisions under the Private Securities Litigation Reform Act of 1995. Actual results may differ materially from those indicated by these forward-looking statements, as a result of various important factors, including the risk factors discussed in our SEC filings, and we are not under any obligation to update these forward-looking statements.

Joining me on today's call are Luca Santarelli, our Chief Executive Officer; Claudia D'Augusta, our Chief Financial Officer; along with Chief Medical Officer, Omar Khwaja; and Kevin Harris, our Chief Commercial Officer. Following the prepared remarks, we'll open up the call to a question-and-answer session.

Now, I'd like to turn the call over to Luca Santarelli.

Luca Santarelli

Thank you, Pat, and thanks to everyone for joining us today.

For those hearing our story for the first time, VectivBio is a growing late stage biopharmaceutical company that is focused on developing potentially life-transforming therapies for people living with serious rare diseases. We are a team of individuals with deep scientific expertise driven by a relentless passion to make a meaningful difference in the lives of people living with rare diseases by developing treatments that are both transformational and tailored to the needs of individual patients.

In 2022, we have made tremendous progress in developing our lead molecule apraglutide, a next-generation GLP-2 analog that bears the promise of unlocking the full potential of the GLP-2 class. Thanks to this unique pharmacology and also our patient tailored development strategy. We believe that apraglutide could transform the lives of people suffering from a broad range of severe, rare gastrointestinal diseases, including short bowel syndrome with intestinal failure or SBS-IF and Acute Graft versus Host Disease or aGvHD.

In 2022, we focused on execution both towards our R&D and corporate goals. And we also positioned ourselves for our next stage of growth. We were able to achieve several key strategic and program milestones despite the challenges that '22 created in the biotech environment. In Q1 2022, we signed a Japan licensing deal with Asahi Kasei Pharmaceutical, designed to develop and commercialize apraglutide in Japan.

In Q2, we announced the dosing of the first two patients in STARGAZE, our proof of concept study in acute GvHD currently recruiting across U.S. and Europe. In Q3, we announced promising interim six months data from the STARS Nutrition study, a first of its kind study in patients with Colon-in-Continuity anatomy or CIC, which represents an under-served majority of SBS-IF patients.

In November, we announced the completion of enrollment for the Colon-in-Continuity stratum of the Phase 3 STARS pivotal study. And finally, we strengthened our cash position by raising a total of $284 million to be a both non-dilutive and equity transactions. The current cash position provides VectivBio with a financial runway into 2025, which is over 12 months after the Phase 3 results.

We believe that 2023 will be a transformational year for VectivBio with clinical readout from STARS Nutrition, STARGAZE, and the Phase 3 STARS, all over the next several months. More specifically, in early May, six months data from STARS Nutrition will be presented at an upcoming scientific conference.

This study aims to demonstrate that apraglutide can improve intestinal absorption and reduce the need of parenteral support in SBS-IF patients with Colon-in-Continuity. In anatomical subtypes of SBS where there is limited data supporting the use of Gattex.

Alongside the progress of the STARS Nutrition study, the enrollment completion in our Phase 3 program of apraglutide in SBS-IF is anticipated by the end of this quarter. At this point, we have closed screening of new patients, as those currently under assessment will enable us to reach the enrollment target based on our current screen failure rates. We plan to issue a press release following the randomization of the last patient.

Moving onto Acute GvHD, I'm happy to announce that we have enrolled all patients necessary to perform the pre-planned interim analysis of our STARGAZE Phase 2 program by the end of Q3. This analysis will help us inform the development and filing strategy in Acute GvHD where apraglutide has the potential to become the first non-immunosuppressive treatment to address GI damage, which is one of the most critical complications of this disease leading to mortality. A positive STARGAZE outcome would also establish the rationale to explore the GI healing and regenerative properties of apraglutide in other inflammatory GI conditions, where the immunological therapy is currently the main therapeutic approach.

Now, I would like to turn the call over to our Chief Medical Officer, Dr. Omar Khwaja, who will share additional details on our pipeline progress. Omar, over to you.

Omar Khwaja

Thanks, Luca, and good morning, everyone.

I will provide more detail on some of the major studies of apraglutide that we'll read out this year. As suggested through this week in Chicago on May 9, we will present important six months data on all nine patients enrolled in our STARS Nutrition study. STARS Nutrition is the first-ever dedicated study in patients with SBS-IF with Colon-in-Continuity or CIC. These are patients where the remnant small intestine remains connected to a functional colon and represent the majority of SBS-IF patients.

The study participants were treated with the same dose used in our Phase 3 study and to whom the same CIC specific parenteral support leading algorithm was applied. The study has two components. The main component is an assessment of PS reduction at six months after the first metabolic balance period. We released interim data on five patients in October 2022, which demonstrated a very robust effect of a 50% reduction in PS volume at six months. We will present data from all patients at this time point.

The study also has an exploratory component, which is the metabolic balance analysis to quantitatively assess apraglutide's effect on intestinal absorption at an early time point of four weeks and a late time point of 48 weeks compared to baseline. We will report data from four week timepoint at DDW where we aim to show data that supports the early positive effects of apraglutide on measures of absorption.

Mid-year, we will have data from the first interim analysis of patients in our STARGAZE Phase 2 proof of concept study of apraglutide in patients with steroid-refractory acute GI Graft-Versus-Host Disease. This disorder is a consequence of attack by donor T-cells on the GI tract. Even with best available therapy, steroid-refractory acute GvHD has a 50% mortality at six months and represents a very high unmet medical need. We're recruiting up to 34 patients who were treated with a high or low dose level of apraglutide on top of corticosteroids and Ruxolitinib.

The interim analysis will include safety, tolerability, response rates, and durability of response in the first 17 patients in this study treated for at least 56 days. All patients to support this interim analysis have been randomized.

Positive data from the STARGAZE can support the pivotal program in Acute GvHD. In addition, we see this data in an immune disease of the GI tract as proof of principle that may unlock the potential for apraglutide in other immune and inflammatory GI conditions such as ulcerative colitis or Crohn's disease.

Finally, by Q4, we will have data from our Phase 3 STARS study in patients with SBS-IF. Positive data will form the basis of our application for approval of apraglutide for use in patients with SBS who are dependent on parenteral support. STARS is the largest clinical study ever conducted in SBS-IF patients, and it's recruiting a 144 patients with prospective stratification to include 50% CIC and 50% stoma.

Study participants are randomized to a single 5 milligrams dose of apraglutide, 2.5 milligrams for patients with the bodies that weigh below 50 kilos, also placebo in a two-to-one ratio. In the placebo controlled phase, several patients are treated for 24 weeks, while CIC patients who are thought to accrue benefits after six months are treated for 48 weeks. The primary endpoint is parenteral support volume reduction at 24 weeks in the whole study population, with common and anatomy specific alpha controlled key secondary endpoints assessed for 24 weeks and 48 weeks.

In addition to the important clinically meaningful secondary endpoints such as days off parenteral support and enteral autonomy, the study also includes an extensive suite of patient reported outcomes to further establish the clinical benefits of apraglutide. All patients from STARS are eligible to roll over into the STARS Extend full year open label extension study. Recruitment has remained well on track. We completed recruitment into the CIC arm with a 48-week treatment period in October 2022.

We are close to completing recruitment into the Stoma arm, which requires a 24-week treatment period. As Luca mentioned, we have closed screening of new patients, as those currently in screening will enable us to reach our enrollment target. Study retention has been extremely good and we look forward to our top line results in Q4. We have made strong progress in the clinical development of apraglutide in SBS, as well as the Acute GvHD and are actively exploring additional indications. We look forward to providing updates from the key readouts in 2023.

Now, I'll turn the call over to our Chief Commercial Officer, Kevin Harris.

Kevin Harris

Thanks, Omar.

In 2022, we've made great progress advancing our launch strategy and plans for apraglutide and have been laying a strong foundation for commercialization over the past three years. We have been focused on four key areas.

The first area is market development. We have a good understanding of the unmet needs and lessons learned from first-generation GLP-2 treatment and the challenges of living with chronic parenteral support which will provide an important foundation for our market development messaging and plans.

The second key area is building our product strategy and branding for apraglutide, where we have completed key long lead time activities in advance of Phase 3 results.

The third key area is market access. We have had significant engagement with U.S. and European payers, which has informed our value strategy in our market access and data generation plan.

The fourth key area is building our patient-centric infrastructure to support the successful launch of apraglutide. We have completed the design work for a high-touch attribution and patient services model to enable a positive experience with apraglutide from day one. We have also designed our compliance roadmap and IT infrastructure plans for launch.

To ensure strong execution, we established a cross-functional launch team, which has been building an integrated and an aligned launch plan. And all of our activities have been significantly informed by listening to healthcare professionals, payers, patients, and the advocacy community.

As we look ahead, 2023 is the year of launch readiness as we continue to finalize and execute our plans in advance to the Phase 3 results. We are already off to a strong start this year. We recently completed a large and robust U.S. insurance claims project, with input from experts. This project had two goals. The first goal was to further refine U.S. projected prevalence of the SBS-IF population and improve our knowledge of patient demographics and treatment characteristics.

We now estimate the number of adult patients living with SBS-IF in the U.S. to be 9,000 and growing. These are patients who have had surgical resections and are on chronic and continuous parenteral support for at least six months. We also estimate an additional 3,000 to 4,000 pediatric patients living with SBS-IF in the U.S.

The second goal of the project was to generate more accurate and actionable targeting information for our commercial deployment strategy. We now have a very good understanding of who is treating SBS-IF patients and where they are being treated and have established a prioritized targeting list at the physician and account level. Account level targeting will be our primary go-to-market approach as we seek to support the multi-disciplinary team that takes care of the patients. We will use this information as the basis for our field force size and structure work, which will begin later this year. We continue to be on track for all pre-launch planning activities and look forward to continuing to update you on the progress of our plans.

With that, I will now turn the call over to our CFO, Claudia D'Augusta to discuss our 2022 financial results. Claudia?

Claudia D'Augusta

Thank you, Kevin.

I will briefly comment now on the key financials for the year 2022. We recognized revenue from contracts with customers of $27.3 million over the year ended December 31st, 2022, related to the Partnering Agreement with AKP.

Research and development expenses were $74 million for the year ended December 31st, 2022, as compared to $50.2 million for the year ended December 31st, 2021. The increase of $23.8 million year-over-year was primarily due to an increase of clinical manufacturing expenses of $16.1 million related to the progress made on our Phase 3 STARS study, the Phase 2 STARS Nutrition study of apraglutide in SBS-IF patients, and the STARGAZE proof of concept study in Acute Graft-Versus-Host Disease and the dual chamber syringe activities.

An increase of $0.9 million of employee expenses primarily caused by the increase in the payroll expenses of $2.2 million, driven by an increase in employee headcount, partially offset with the decrease of the non-cash share-based compensation of $1.3 million and the impact of $6.9 million related to a revaluation gain of contingent liabilities recognized in 2021.

General and administrative expenses were $33.9 million for the year ended December 31, 2022, compared to $36.5 million for the year ended December 31, 2021. The decrease of $2.6 million year-over-year was mainly attributable to a decrease in employee expenses of $5.4 million primarily caused by a decrease of the non-cash share-based compensation of $6.8 million, partially offset with an increase in the payroll expenses of $1.4 million, driven by an increase in employee headcount and an increase in professional services expenses of $2.1 million, mainly due to corporate activities.

Cash and cash equivalents were $221.4 million as of December 31, 2022, compared to $102.7 million as of December 31, 2021. Based upon our current operating plan, we estimate that our existing cash and cash equivalents will enable us to fund our operating expenses and capital expenditure requirements into 2025.

Now, I'd like to hand the call back to Luca.

Luca Santarelli

Thank you, Claudia.

We covered a lot of ground during today's call and to close, I'd like to underscore the following three points. First, 2023 promises to be a transformational year for VectivBio as we will readout important datasets, including a six-months Nutrition data in just the couple of weeks followed by the interim analysis of the Phase 2 STARGAZE study and then perhaps most importantly topline results for our Phase 3 STARS study.

Second, we're executing a comprehensive launch preparation plan with the aim of achieving a blockbuster launch of apraglutide in SBS intestinal failure. And finally, we are operating from a position of financial strength with a cash runway that takes us more than 12 months past the top line readout of the Phase 3 STARS study.

And with that, we would like to open the call for questions. Operator?

Question-and-Answer Session

Operator

[Operator Instructions] The first question comes from Allison Bratzel with Piper Sandler. Your line is now open.

Allison Bratzel

Hi, good morning, guys, and thanks for taking the questions. So, just first on the STARS Nutrition update at DDW, could you just frame for us the scope of the data that's going to be available next months and just what measures, body weight, what weight absorption or other metrics in addition to parenteral support reduction are going to be most important to illustrating the benefits of APRA in the CIC population? And then I do have a follow-up question after that.

Patrick Malloy

Hi, Allison, thanks for your question. Thanks to jumping on today. How about we have Omar to handle the first question.

Omar Khwaja

Yes, thanks, Allison. So at DDW as well as the PS volume reduction will also show the energy content of the PS over a number of the mass calories in the PS and how that's changed over the six months period and then also what happened to the patient's body weight over that timeframe.

Allison Bratzel

Great. And then just on the STARGAZE read out this quarter, can you just kind of frame for us what you need to see to feel like you've established proof of concept in GvHD and also to feel like you've established proof of principle in inflammatory GI diseases more broadly. And I'm just hoping you could also describe your thinking on the opportunity or the role of APRA in larger indications like Crohn's and UC and just how the STARGAZE interim data kind of informs on your strategy there?

Patrick Malloy

Great. I think we'll have Luca take that question.

Luca Santarelli

Thanks, Alli. So, in terms of what we'll report in that analysis, we likely will report the effects of the drug on overall response rates both one month and two months and durability of response, which obviously have a precedent as endpoints from previous trials assessing, for example, Ruxolitinib in this indication.

And the exact bar has been set by the data that was generated in the past, both with Incyte and Novartis in their REACH-1 and REACH-2 trial as well as other datasets that we have been able to access in Germany and in the U.S.

And we will create that comparator group from those combined datasets. The importance of those datasets as such because we -- all of those have as standard of care Ruxolitinib and of course steroids. And we're able to extract all the patients that had GI symptoms among -- which represents about 80% of the patients in steroid refractory GvHD. So, it's a very appropriate dataset. In terms of where the bar is, we'll communicate that as soon as we have that -- those datasets finalized.

In terms of new indications, well, first, I would say, I would like to start by saying that clearly the novelty of this approach is that we're combining regeneration of the intestine and healing of the intestine with immunosuppression. So, immunosuppression in these patients is crucial to dampen the alloimmune response from the engrafted tissue and is achieved by steroids and other immunosuppressants such as JAK inhibitors.

And then you combine with those standard of care, you combine the GLP-2 mechanism, which adds guttery growth as well as increased barrier function, healing, improvement in absorption, all of those features that are known to be part of the GLP-2 mechanism.

But the importance of this proof of concept is that this can be extended to additional immunological condition of the intestine and we think that it's the next place to looking for opportunity when it comes to apraglutide and of course, they had the notion and the cost that would be similar will be combining our drug with existing immunosuppressant therapy, for example, anti-TNFs or anti-integrins that are currently the standard of care biologics in this indication or at least second line in these indications.

Allison Bratzel

Great. And maybe just one last one. I think you talked about developing our pre-filled syringe or dosing for syringe. Could you just remind us kind of what's the status of that? And just if you've a sense of what kind of data you need to generate to get a pre-filled syringe for APRA approved? Thanks.

Luca Santarelli

Yes. So, we're developing with the timelines that is compatible, we're launching in 2025 with such a device, a drug device combination. So our main case is to launch -- our base case is to launch with the dual chamber prefilled syringe. We're going through a series of planned programs in the development of this syringe including human factor studies, including [indiscernible] studies and or bioavailability studies and validation studies that are purely on the CMC side and all of that is work is progressing in parallel with the conduct of the Phase 3.

We have completed the GMP manufacturing that will be required for the relative bioavailability study which is due to start imminently. So, we're basically on time for a launch with the dual-chamber syringe.

Allison Bratzel

Excellent. Thank you.

Operator

Please standby for our next question. The next question comes from Tazeen Ahmad with Bank of America. Your line is now open.

Tazeen Ahmad

Hi, guys. Thanks so much for taking my questions. I have a couple. So, maybe just conceptually, Luca, can you explain to us like we've been getting a lot of inbounds with interest specifically the CIC population that is enrolled into the STARS study. Obviously, the competitive landscape is wide open for CIC, but I think it would help if you could frame for us why you think apraglutide in particular has a better chance of showing higher success rate in CIC patients mechanistically relative to what's already on the market and from competitors? And then I have a follow-up. Thank you.

Luca Santarelli

Well, there's two reasons. One is that -- one is molecule specific and the other reason is design -- trial design specific. So when it comes to the molecule, we believe our molecule has one of the greatest features pharmacologically speaking, both in terms of half-life and pharmacology like affinity to the receptor that make it more potent as shown in published preclinical head-to-head studies and then when it comes to the line, I think, this point is actually perhaps just as important, if not more important, CIC patients are physiologically different from stoma patients. They display response to drug in a way that is distinct from Stoma patients.

The all methodology for detecting response and adjusting parenteral support in clinical trials was perfected for Stoma patients but not for CIC patients. And we have evolved that methodology as shown in our Nutritional trial while that methodology was deployed for the first time to basically be increase the sensitivity of the testing the response in CIC patients.

So essentially we are enhancing both the chains of seeing a response because of the molecular nature of apraglutide as well as for the methodology used in the trial. And, of course, to be more specific in CIC patients, the focus in terms of tracking their response is more on changes to their metabolism, changes to their body weight, their stool, consistency, or frequency and less so on the fluid balance changes. In other words, diuresis and absorption of fluids, which are more critical for Stoma. Those are the key differentiation aspects of the trial design.

And lastly, I would add to that, Tazeen, ethe fact that being able to inform the use of the drug in a bespoke fashion in a patient tailored fashion in the two sub-types will also increase the adherence to treatment and the ease of use and compliance and persistency, which are critical objectives for our drug once is on the market. So to help make the use easier and more appropriate with patients, something that has been left on the table we think from the past experience of the pioneering experiences of Gattex.

Tazeen Ahmad

Okay, that's super helpful. Is there anything that we should be looking for at that topline for the STARS results as it relates to CIC? You talked about some of the observations that might be more important for those patients. But as it relates to those endpoints, are there certain cut off that you think are necessary in order for this to be considered clinically meaningful data in that subgroup?

Luca Santarelli

Well, in a CIC subgroup, we put a lot of emphasis. First of all, there's a couple of different aspects that are relevant. The timeline or the response is it focused more on metabolic changes and less on fluid changes is a bit longer. So the expectation to add a very quick response, it should be tempered for this patient. That's why we ran our Phase 3 trial and our Nutrition trial for 48 weeks is double the duration of what we've be done for Stoma and what has been done in the past. The other point is, we expect the effects not to stop six months to accrue beyond six months.

So, basically will likely we hope and we likely able to demonstrate that there is still benefit for patients to be on treatment beyond six months in a nine month to 12-months timeframe. And then we can record maybe a larger effect size beyond the six months point for this group and again that's why we kept the STARS Phase 3 trial blinded for these patients all the way to 48 weeks.

In terms of what outcomes are more relevant for these patients, of course, is these are patients that are more likely to being able to shave days off, because they don't dehydrate as readily as STARS patients. The dehydration is a key enemy of being able to come off days of infusion because one can dehydrate very quickly within a 24-hour period.

And secondly, so again days off is a crucial endpoint that we have at the top of our hierarchy. And then another point is obviously enteral autonomy or complete win off from parenteral support, which we think is more achievable for CIC than it's for Stoma patients. Again for the same reason they have less of a propensity to dehydrate, it start from fewer days a week on average of infusion, so achieving a full enteral autonomy it's potentially easier for these patients.

Tazeen Ahmad

Okay, perfect. Thanks, Luca.

Operator

Please standby for our next question. The next question comes from Thomas Smith, SVB Securities. Your line is now open.

Thomas Smith

Hi, guys. Good morning. Thanks for taking the questions and congrats on all the progress. Couple of questions on our end. I guess first a follow-up question on the STARS pivotal trial and some of the assumptions you're making for the CIC patients. We know in the Gattex program, there was a 24% reduction in PF volume in the placebo arm for CIC, but that was what the titration algorithm that relied only on changes in fluid balance. How do you expect the CIC patients who received placebo and STARS to respond using your algorithm relative to the Gattex study? And can you remind us of the assumed treatment effects and powering assumptions for the anatomy to specific endpoints?

Luca Santarelli

Thanks for the question. So basically we're -- we've changed the -- not just the winning algorithm which should increase the sensitivity of the detection response with CIC, but we have also changed significantly the optimization mechanisms that are designed to reduce the placebo responses in this population.

Essentially, what was observed in the past was on average a 20%, 22% placebo response, which was attributable to patients during the course of this trial requiring less parenteral support irrespective of the GLP-2 treatment because of a better optimization of that nutrition, oral nutrition or parenteral support nutrition.

So we have invested significant amount of effort and time in making these patients very stable and optimized before they start receiving drug. So again, so these two factors, the placebo response reduction and winning algorithm which we tested already in the nutrition trial are predicted to give us a more significant signal in the CIC subgroup.

Now, in terms of what we have powered towards for the CIC, we powered -- the study was powered for the overall effect size, but I would say specifically the CIC we powered it to about a 10% delta between placebo and an active. So it's a relatively small delta that we are aiming for here. What we have seen in the nutrition trial would indicate that the data could be as big as 30%.

But of course, we have to assume that in a placebo-controlled trial, we may not get that large delta between placebo and an active simply because these are more typically when you run trials on a large number of sites and large number of countries, the [female] patient diminishes. So, we think that the nutritionally which has a reduction of about 50% if you assume 20% placebo is about close to 30% delta there. I think that will be sort of the best case scenario.

Thomas Smith

Got it. That's super helpful. Great. And then just one on the competitive landscape in SBS. Can you just update us on your latest expectations for competing GLP-2 programs and generic Gattex and how you see the market shaping up over the next three to five years?

Luca Santarelli

Yes. I'll start and then I'll allow Kevin continue. In terms of the expectations from other sponsors were using our comment about our programs. We're confident we have a very competitive package here. We are the only company with a weekly drug. We are the only company with an ability to discriminate between different anatomical subtypes, which we think is very crucial for this population.

And we are the only company that has a significant amount of patient reported outcomes that are bespoke that were designed specifically for this population. And so there's plenty and if you combine that with what we know about our molecule versus the others, we're very confident, we have a very high chance to differentiation.

In terms of the generic landscape, I think we now are further advanced into the generalization of Gattex. I'll have Kevin comment on that so because he has done a lot of work in this space. Kevin?

Kevin Harris

Yes. Thanks, Luca. As you may know, or may be aware of, there could have been a possibility for a generic of Gattex to launch in the second half of March of this year and we haven't seen one emerge at this point. We think there's a lot of reasons why both the SBS-IF market and the profile of Gattex in particular have limited attractiveness for generics. There's some challenges one has to overcome in transitioning from the recombinant manufacturing approach for Gattex today to synthetic manufacturing, which would be required under the -- and guidelines and that clearly would require pretty significant CMC investment.

It does take some effort to identify patients and to keep them on treatment. As we've shown patients on Gattex have significant challenges with persistency and half of them discontinue by month 12 and up to two-thirds by month 24. There is REMs and registry requirements for Gattex. And so these are just some of the factors we think why the market isn't particularly attractive for generics. We've only seen one paragraph for filing to date and that was done back in 2016 and we still have not yet seen an approval.

So, yes, I think a generic remains to be seen whether one will come to market. If one does come to market, we've had significant engagement with payers. And at the end of the day, they view generic Gattex as Gattex without a lot of the support that a corporation would provide. And as Luca mentioned, we believe we'll be able to demonstrate very significant differentiation on efficacy and obviously on dosing being a weekly dose drug. So we don't see a generic as a strategic threat to the opportunity that we think apraglutide have in SBS-IF.

Thomas Smith

Got it. That's super helpful. Thanks, guys, for taking the questions.

Operator

Please standby for our next question. Our next question comes from Patrick Dolezal with LifeSci Capital. Your line is now open.

Patrick Dolezal

Hi, thanks for taking the questions. It's interesting thinking about the speed of CIC enrollment and now kind of waiting a little bit longer for the stoma cohorts. Just curious, what's the relative proportion of CIC versus stoma patients currently receiving Gattex and how might your marketing strategy and pivotal trial design ultimately kind of shift this ratio over time?

Luca Santarelli

Yes. So, hi, Patrick. So basically the -- we have different sources of information that we can rely on including our own study experience in 18 countries and feasibility work we've done that's leading up to that, including market research we are conducting both in the U.S. and in Europe. So we estimate the CIC population to have increased since the first launch of Gattex because of greater appreciation of the importance of keeping at least a portion of the call on impact to provide patients with the ability of absorbing fluids. And so we have seen an increase in proportion. We estimate that the number of CIC could be anywhere between 60% to 70%.

We don't obviously know exactly the exact number, but that's sort of, I would say, a fair estimate would be around 65% versus 45%, 35% many not be now with stoma. And what was the other part of the question?

Patrick Dolezal

I think it was, how it may impact our marketing approach.

Luca Santarelli

Okay. So maybe we'll have --

Patrick Malloy

Yes. Kevin, do you want to take the second part of the question?

Kevin Harris

Yes. And we've got a couple of data points to suggest that Gattex is used at least 1.5 times to 2 times more frequently in stoma than CIC recognizing that CIC represents the majority of patients and so we've always believed that these patients have been underserved. We obviously have seen that Gattex in a retrospective analysis didn't demonstrate any effect in that population.

We also have a good understanding that that is one of the main drivers of discontinuation for Gattex, which is lack of efficacy in particular in the CIC population. So much of our strategy beyond obviously having a product with better pharmacology is really to address the unmet needs by anatomy.

There's certainly significant room for growth in the stoma population because our market research indicated that still less than half of patients might be getting Gattex in that population, but really the market growth potential and the long-term potential of apraglutide can be significantly driven by that 60% to 70% of CIC patients, of whom only a fraction are getting Gattex today.

So our design of the Phase 3 trial with anatomy specific endpoints and our ability to be able to demonstrate in a prospective alpha controlled manner, days off and until our autonomy in the CIC population I think uniquely position us to be able to proactively promote and educate people not only on the benefits of APRA, but as Luca mentioned earlier, how best to measure APRA's effect into appropriately whine the CIC patient off of PS.

So I think there's very tight integration between our development strategy and our commercial and marketing strategy, and I think we're well positioned for success.

Patrick Dolezal

Got it. And in the STARGAZE trial for GvHD, could you just walk us through how GI involvement in particular effects outcomes? And then, just curious, how the propensity control arm is kind of handled? Do you guys have patient level data to kind of match disease characteristics and other features?

Omar Khwaja

Yes. Thanks, Patrick. So that's the actual injuries that the got so patients in preparation for stem cell transplant undergoes conditioning and that itself is toxic to particularly to the gut epithelium, which is there which is continuing to providing tissue. And then post-transplant, the donor T-cells, which are contained in the graft attack the host and their GI tract in the liver and skin are the primary targets for that. And that basically in the gut that leads to a profound inflammatory condition, which often leads to their mucosal of the gut being denude and the patients develop a quiet life threatening bile salts and osmotic diarrhea.

And the other problem is that the gut barrier itself becomes intestinal barrier becomes impaired as well and so transportation of bacteria across from the gut lumen into the bloodstream, and the patients will develop stress. So the GI tract thought to probably account for significant proportion of the mortality though the scale and level were typically are reasonably well addressed with immunosuppression but it's gut that kind of remains a significant unmet need in the population.

Patrick Malloy

Great. Thanks so much. Patrick, is that answer your question?

Patrick Dolezal

Yes. And then I guess the second, what was your conduct propensity match control arm -

Omar Khwaja

Yes, so we do have patient level data and the propensity score matched and basically is used to ensure that we've got a well matched synthetic control to compare our outcomes from Stargaze.

Patrick Dolezal

Got it, perfect. Thank you.

Operator

I show no further questions at this time. I would now like to turn the conference back to Luca Santarelli for closing remarks.

Luca Santarelli

Thanks to everybody for participating, and to all the people that participated in the Q&A for your insightful questions and for helping us continue to become a better company. Thank you.

Operator

This concludes today's conference call. Thank you for participating. You may now disconnect.

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VectivBio Holding AG (VECT) Q4 2022 Earnings Call Transcript