Welcome to the Cantor Global Healthcare Conference. I'm Pete Stavropoulos, a Biotech Analyst with Cantor. With us, we have Eledon, a company I cover. I'm pleased to introduce Eledon's CEO, D.A. Gros, and CSO Steven Perrin. Thank you for joining us and for your time.
Thank you for having us. It's great to be here. Before we start, we'll be making some forward-looking statements. I encourage everyone to look at our disclaimers.
All right. With those disclaimers in place, let's just dive right into your lead program, the tegoprubart, which is currently being evaluated in both a phase I-B and a phase II. It's an alternative to calcineurin inhibitors in the prevention of kidney transplant rejection. Just help us understand what the unmet need is and what the problem tegoprubart is trying to solve for as an overview, giving us an overview of the current standard of care and sort of short-term and long-term outcomes for those patients. What's the issue?
Sure. Kidney transplantation today, if we look, which is the most common type of transplant, so I'll focus on that. What I'm about to say is also true more broadly. Transplant medicine uses a standard chronic immunosuppressive regimen that includes three drugs, but the cornerstone of which is a type of drug called a calcineurin inhibitor. Today, the most commonly used calcineurin inhibitor is tacrolimus. Tacrolimus was approved in 1994. Since 1994, the current standard of care has basically been the same. The unmet need is to replace tacrolimus. There are very few things that we do the same way as 30 years ago. This drug, while it was one of the ways that modern transplant medicine was launched, has a number of limitations tied principally to its adverse events. The drug itself is nephrotoxic. It also has side effects that include causing hypertension.
It's beta- cell toxic in the pancreas, so it causes hyperglycemia and new-onset diabetes. That's insulin-dependent diabetes. As you can imagine, because of those three, that has an impact on how well transplanted kidneys do, since you have both indirect and direct nephrotoxicities. The unmet need is to improve just patients' lives and how they feel, and they're not having to deal with what are obviously very significant adverse events, as well as improving how long organs can survive. Our hypothesis is that if we can remove the side effects of the tacrolimus, as well as better protect organs immunologically, patients should do better, and organs should survive longer than they currently do today. Today, the average kidney that gets transplanted survives between 10 years- 15 years. The average age at which a patient gets a transplant in the U.S. is only 50.
Patients that are 20, 30, 40, 50 may need multiple transplants. As we all know, we don't have enough organs. Putting that patient at risk for not being able to get another transplant.
OK. In order to help sort of frame the kidney transplant clinical trials, what are the likely approval endpoints that we should be focusing on?
Historically, the approval endpoints in transplant are a composite endpoint made up of patient and graft survival, as well as biopsy-proven rejection. The field has been changing over the last 10 years or 15 years as we try to solve for longer-term kidney function and survival because biopsy-proven rejection is not a predictor of long-term graft survival. New composite endpoints have been developed, such as iBOX, which is made up of eight different typically collected clinical data points. Four of them are not associated with a biopsy at 12 months. Their kidney function is measured by eGFR, which is the best predictor of long-term graft survival, DSA, proteinuria, and time since transplant. Those are the four components that are part of what we would call abbreviated iBOX. If you collect that data at 12 months post-transplant, it's a very potent predictor of long-term graft survival.
The rest of iBOX, the other four parameters, are associated with the histology of what the graft looks like at 12 months post-transplant.
OK. Are these different sort of outcomes, not outcomes, but measurements, weighted differently in iBOX?
They are weighted differently. It's a composite endpoint made up of those four or eight endpoints. They are weighted differently, with eGFR being the most highly weighted in the mathematical calculation.
OK.
What's important here is to note what the FDA is considering as the potential new approval endpoint to transplant is that the baseline is non-inferiority, and the potential upside is superiority. One can get approved just with non-inferiority. What the FDA is considering now is the potential to grant companies or drugs superiority, if you will, as an additional label statement.
OK. Superiority would be based on an iBOX score, not another.
Inferiority would be based on?
Non-inferiority would be based on a composite, which is, as Steve mentioned, organ survival, patient survival, and rejection.
OK. You did present kidney transplant data recently over the summer, having upcoming kidney transplant data as well in 4Q from the phase II. Just walk us through the study designs and endpoints related to each of those readouts.
Sure, Pete. As you mentioned, we have two ongoing studies. We have a phase I-B study that we presented data at WTC a few weeks back. We have a phase II study where last patient last visit is occurring this month. We're guiding that we'd be presenting data for that study coming up at Kidney Week. The foundation of both of those studies is to replace tacrolimus as the current standard of care in the maintenance part of immunosuppression. The induction treatments are very similar with ATG and a steroid taper, then followed by MMF and tegoprubart as long-term maintenance therapy. The phase I is an open-label study, primary endpoint safety and tolerability. Obviously, we're collecting all of the other endpoints that we just discussed as far as rejection rates, patient graft survival, eGFR, kidney function is measured by eGFR, as well as the side effects that D.A.
was discussing that are associated with CNI exposures, like new-onset diabetes, hypertension, nephrotoxicity, et cetera. The phase II study is the first superiority design going head- to- head with TAC. It's 120 patients randomized one- to- one, 60 per arm. Primary endpoint being kidney function at 12 months is measured by eGFR. The study is powered to detect an eight-point difference between the two arms. We're again collecting all of the other endpoints that we've been discussing that are associated with graft survival, graft function.
OK. You did present, excuse me, phase I-B data at WTC, starting off with kidney function. What's the outcome at 12 months? Understanding this is a small sample size and cross-trial comparisons, how does this sort of stack up against tacrolimus?
At 12 months in the study, we reported eGFR at 12 months of 68. That was for patients that were on treatment. We've been guiding to that ever since we presented our first cohort of patients a year ago, where we had about an N of 13. In this particular study, we presented all of the data for 32 patients with all of the ones that had made it out to 12 months going into that final calculation of an eGFR of 68. Historically, on standard of care with tacrolimus, most repositories are reporting data that eGFR is in the low 50s on tacrolimus at 12 months.
All right. Do you want to talk about our iBOX similarly?
Sure. The other thing that we report to the first family is we utilized the iBOX calculation for abbreviated iBOX at 12 months for all of the patients in the phase I that had reached that 12-month endpoint. The iBOX scores we presented were in two different buckets. There was the intent-to-treat group, as well as the on-treatment group. The on-treatment group had an iBOX score of - 4.1. The larger the negative number, the more predictive of long-term graft survival. In that figure, there was also historical data from multiple studies that went into the actual ability to utilize the iBOX parameters to predict long-term graft function with one-year data. If you look at those, the average CNI iBOX score is a - 2.9. We performed significantly better than any of the other studies, including the BALAD sub-studies as far as iBOX score at 12 months.
iBOX is a very potent predictor of long-term graft survival with CSAT scores of around 0.8 compared to biopsy-proven rejection, which actually has a CSAT of 0.5, meaning it's completely random. It does not predict long-term graft survival.
Would it BALAD sub-study sort of fall into this?
There were two different BALAD sub-studies in that study. Off the top of my head, without the slide in front of me, they were in the 3s, - 3.5 and I think - 3.2.
All right. I guess the key point that I'm trying to sort of get at is you have great long-term survival or long-term graft function preserved with BALAD sub-studies.
The consortia that's been working with health care authorities to approve iBOX as a new endpoint for transplant has guided that a 0.4 difference in the iBOX score is clinically meaningful. With our negative scores of -4 .11, certainly that's better than even the BALAD sub-studies that were utilized to help develop the algorithm.
OK. I guess the second key outcome investors sort of look at is acute rejection. Can you just talk about the acute rejection rates? How significant were they? How did they compare to tacrolimus and BALAD sub acute rejection rates?
The rejection rates that we reported were 18% in the phase I-B study at 12 months. That's in line with what BALAD sub-studies have reported, which were in the low 20s. Standard of care, as you know, are in the high single digits. The community has had 30 years of experience on how to utilize tacrolimus as part of maintenance therapy for transplant rejection. We had guided that our rejection rate would probably be similar to what we had seen in BALAD sub-studies. As far as rejections go, they were very treatable rejections. They tend to be cellular-mediated rejections, which are often treatable with either a dose of steroids or a dose of ATG. We obviously encourage sites to keep patients on tegoprubart and treat those rejections with either steroids or ATG. That's based on 15 years of BALAD sub-studies data.
Over the long haul, from the early 12-month data with BALAD sub-studies to the three, five, seven-year follow-up, it became apparent that even though BALAD sub-studies had a higher rejection rate, so acute cellular rejection rate than standard of care, if you kept patients on BALAD sub-studies, their kidneys did much better. They had better kidney function and they had better long-term graft survival.
The FDA has commented in terms of rejection that it recognizes that not all rejection is the same, and that rejection can vary based on the type of immunosuppression that a patient is on. The FDA commented on this and pointed actually to belatacept, to your point, saying that belatacept, while it has more frequent and worse rejection when looked under microscopes and when graded by BANFF, those patients end up doing better. The organs survive longer, and their kidney function is better.
All right. How do you sort of square that in terms of those outcomes?
You mean why would rejection not matter? The answer is rejection is diagnosed the same way that it was diagnosed decades ago. It's a histopath diagnosis. They look under a microscope. The pathologist looks under a microscope. If there's an infiltrate into the graft, it's a grade 1 rejection. If there is immune infiltration into the vasculature, it's a Grade 2. We all know that immune infiltration is not equal, right? Even a B cell is not a B cell. A T cell is not a T cell. It's a gross way of looking at what's happening. As a result, it's not associated with any more of even short or long-term organ survival.
All right.
It was very important 60 years ago.
It was, I mean, stepping stone. You learn, you have new tools.
This is acute cellular-mediated rejection. There are other types of rejection as well, which is not what we're talking about.
Yeah, it's antibody-mediated and so forth.
I guess one of the questions that comes up with investors is why not have patients on tegoprubart and CNI for the first, let's say, 6 to 12 months, and then pull them off the CNI and remove that nephrotoxic agent? What are your thoughts on that?
It's a great question. There's a possibility, a theoretical possibility of doing a combination. Maybe that could lead to less rejection. The question is, what would be the benefit of combining the two? We just finished discussing that there's little relationship between acute rejection, cellular rejection in the first year, and outcomes. We do know that using tacrolimus causes things like new-onset diabetes. We would be swapping a potential theoretical decrease in a rejection that might not have long-term sequelae for side effects like insulin-dependent diabetes that will have sequelae for the rest of a patient's life. Those sequelae can also include things like tremor and, of course, hypertension.
Moving on to the phase II bestow study, what are the power assumptions there? What type of difference are you trying to detect in eGFR?
As Steve mentioned, we're 80% powered to detect a nine-point delta in eGFR.
What are some of the protocols for induction therapy with ATG? How does this compare to phase I-B? What I'm trying to understand is if we should expect similar rejection rates in the phase I as the same as the phase I-B, more or less, since it was four out of six patients that experienced rejection with a low dose of ATG in the phase I-B.
Sure. To your point, what we saw in our phase I-B is that low dose ATG, although it was in small n, appeared to be associated with a higher frequency of rejection. Our induction regimens are quite similar in the phase I-B and the phase II in the first cohort of our phase I-B, where to a large extent, it's to the surgeon's choice of how they wanted to do induction therapy. Surgeons can go up to, in the phase I-B, 6 mg per kg. In the phase II, the recommended dose was slightly lower, which is up to 4.5 mg per kg. 6 mg per kg is the label dose. Most physicians today use about 4.5.
Is there a minimum?
There is no minimum.
They can do whatever they want to do?
They can do whatever they want.
OK.
The reason we do a phase I-B and the reason we do a phase II is to learn.
Oh, not just the phase I-B, the phase II.
The phase II . The reason we do the phase II is also to learn to dose our drug. We will learn about how the rest, these patients are in polypharmacy. If we learn about how to best manage the polypharmacy, that would obviously be very helpful as we design our phase IIII.
What are our expectations? Also, just touch on the phase 1B in terms of safety profile, especially infections.
I mean, look, our safety profile in the phase I-B looked very good. What was striking was what we didn't see. We didn't see things that you typically see on tacrolimus. We didn't see graft loss. We didn't see delayed graft function. We didn't see deaths. We didn't see drug-induced tremors. To your point, you asked about infections. One of the things we did not see is sepsis. Sepsis can put patients in the intensive care. Patients die from sepsis. We didn't see any sepsis. You asked about other types of infections. We did see some viral infections in a similar manner that they're seen on standard of care.
How are they sort of managed?
There are two primary types that people look at, BK as well as CMV. CMV is managed with antivirals. BK is managed by temporarily decreasing one of the immunosuppressants the patients are on. The mycophenolates get decreased to allow the immune system to come back a little bit and to take care of the BK.
All right. What would actually be a win for you in the phase II, your perspective on that one?
I think the win is to show that we have a drug that, if we could repeat it, has a path to approval. The basic win is to be able to hit the non-inferiority versus tacrolimus. What we're trying to do, and we obviously designed the study to do, is for the grand slam, which is to have superiority. Of course, tied to both of those is the better safety profile versus tacrolimus.
All right. Yes. Now, in the last few minutes that we have, how do you view the current market opportunity for kidney transplants? For example, how many kidney transplants are there in the U.S. on a yearly basis? What's the U.S. transplant immunosuppressant market size estimates?
Sure. Transplant is a large market. It was one of the first blockbusters going back to cyclosporine, which was approved in 1983. After cyclosporine, tacrolimus, which we've been talking about, peaked at multiple billion dollars in branded sales. In fact, it still does. Astellas has it, and 30 years post-launch, it's still doing almost $1.5 billion in branded revenues. This is a market that's been proven to be able to sustain blockbusters. In the U.S., there are about 48,000 transplants every year, just under 30,000 of which are kidney transplants. What's striking is that this is also a very concentrated market. There are only 40 centers or so that account for half of those transplants, and about 100 centers account for 80% of the transplants. It's rare disease-like, and it's a nice market for a smaller biotech because to commercialize here, one doesn't need a big sales force.
Would you say it was 40 centers, what?
50% of the market.
All right. How many of those centers are you doing your clinical studies?
A large number of those already use tacrolimus.
Exactly. They're getting the experience.
They're getting the top 100 centers. We already know. I mean, it's a very small community.
All right. If we're sitting here a year from now, what would you like to say has been sort of the key value-creating accomplishments for Eledon?
In a year from now, we're going to have many value-creating episodes that we expect to occur. The first one, kidney transplantation, is of course getting our data from bestow. Afterwards, we're going to get clarity from the agency on the phase III endpoints and the ability to use superiority as a.
Yeah. When is that supposedly going to happen?
The expected is April.
OK.
For that feedback?
Yes.
We expect to launch our phase III in the second half of next year in kidney transplant. Islet cell, we expect to have nine patients transplanted by the end of this year, so more data next year. That should be sufficient to also go and talk to the agency about path to approval in islet cell. Of course, xenotransplantation, we recently announced that a third kidney xenotransplantation had been done at MGH. We expect more xenotransplantations to be done, as well as a number of other ISDs that we have kicking off. We'll have a lot more data coming over the next 12 months. It's a particularly exciting time and one that could see us moving soon into one or multiple phase IIIs.
Excellent. I want to thank you both for participating in our fireside chat. Always nice seeing you, and looking forward to the phase II data in a couple of, I guess, months.
Thanks. Good to see you.
Likewise.
Thank you, D.A.
Thanks, Pete.