Tenax Therapeutics, Inc. Aktie

Good day, and welcome to the Tenax Therapeutics Phase 3 LEVEL Topline Results Conference Call. [Operator Instructions] Please note this event is being recorded. I would now like to turn the conference over to Chris Giordano, President and Chief Executive Officer. Please go ahead.

Good morning, everyone. Thank you, Betsy. Thank you, everyone, for joining us. I'm Chris Giordano, President and Chief Executive Officer of Tenax Therapeutics. This morning, we released topline results from LEVEL, our first Phase 3 trial of oral levosimendan in patients with PH-HFpEF. The primary endpoint did not reach statistical significance. The difference between groups in 6-minute walk distance at week 12 was 3.5 meters with a p-value of 0.63. But the evidence we will share with you today impresses us.

Levosimendan's impact on key objective biological targets directly translates benefit from pulmonary pressure and BNP lowering to functional improvement in the more advanced patients we treated. We believe we have a drug for the many patients who need it, and there are millions of them around the world. Our Phase 2 HELP results found a new target population for this unique drug. LEVEL was always intended to validate the efficacy shown in that study, more precisely measure the treatment effect and establish the right patients who benefit in this very heterogeneous HFpEF population.

Trial did not meet its primary objective, but when it comes to sizing and locating the treatment effect in these patients, the trial has achieved very important goals. We received data only last week. In beginning to dissect it, we see evidence of a very responsive patient population in LEVEL. And we also see the reason their response is obscured in measurement of the primary endpoint. We see clearly where one inclusion criterion let this drug down in this study.

What I will tell you today is this, our therapy works very effectively in a large, common, easily identifiable population of PH-HFpEF patients, and they need it. We are not in a situation where the drug and the placebo groups are indistinguishable in our data or a situation where drug exposure or adherence was inadequate in the trial, at least not in the full analysis set we're looking at. On the contrary, our results define the population of high responders coherently and the adjustment we need to make in our Phase 3 program is crystal clear.

LEVEL was a well-conducted trial. It was executed on time, randomizing 241 patients in about 24 months with a reassuring 2% rate of missingness on the primary endpoint, very high patient retention and therapy adherence and no site-specific problems or 6-minute walk test performance anomalies we're going to point to as a culprit behind the primary miss. We have invaluable information from LEVEL, and we intend to use it. So here's how we will use our time this morning.

Dr. Stuart Rich, our CMO, will take you through the complete topline data set, the primary and secondary endpoints, the safety profile, the biomarker and hemodynamic results that yield important information about the efficacy of levosimendan in a well-defined PH-HFpEF population and then the subgroup analyses, which will guide the direction of our program from here so that the drug's effect is not obscured a second time.

We will then hear from Dr. Sanjiv Shah, Professor of Medicine and Director of the HFpEF program at Northwestern University and LEVEL's principal investigator. I will close by discussing where our Phase 3 program goes from here. Then we will open the line where Stuart, Dr. Shah and I will be joined by Doug Randall, our Chief Business Officer; and Thomas Staab, our Chief Financial Officer. Before we go further, we will be making forward-looking statements on this call, including statements about our clinical data, regulatory plans, our future trial designs and our business operations, all of which are based on management's current expectations.

Actual results may differ materially from those indicated on this call due to inherent risks and uncertainties described on this slide and in the company's SEC filings. Please read them accordingly. Although we may voluntarily do so, we undertake no commitment to update or revise forward-looking statements, except as required by law. Now before Stuart walks through the results, let me tell you how we are reading the evidence we have. So you have a frame for what he's about to show you. Let's start with what this trial confirmed because it is much more than people may assume from the headline. LEVEL started out with several key questions still outstanding.

Is chronic oral levosimendan safe in the population tested? The answer is yes. Do we have a clear and robust set of evidence of a dose that is biologically active with NT-proBNP and pulmonary pressures both responding in the way this mechanism predicts they should? Yes. The Phase 2 efficacy results from HELP were unprecedented in Group 2 patients, but were they reliable? Would we be able to validate the treatment effect we saw in those 36 advanced PH-HFpEF patients? Again, yes. Can the sites and the clinical operations team execute? Yes.

The reason those answers did not convert to a win on the primary is apparent. It actually jumps off the page at us in the first hours of our review of the data. Tenax did not anticipate the impact disease burden would have on the treatment response. In patients whose baseline walk is below the median of 333 meters, the result is not 8 meters or 3.5 meters, the placebo-corrected improvement below the median is 26.3 meters with a 95% confidence interval of 6 to 47 meters and a nominal p-value of 0.0112. Above that line, healthier placebo patients outwalked healthier levosimendan patients by 17.6 meters.

Now it's not hard to find patients with limited exercise function in HFpEF practices in clinical trial sites. A patient's track record on this standard assessment is one of several markers of advancing disease their cardiologists follow closely over time. In the results we have reviewed thus far, these markers of severity align in predicting exercise improvement levels from levosimendan. And we are moving forward knowing the 6-minute walk distance at baseline in particular, highlights patient responsiveness to our mechanism of action.

We know much more clearly the right patients to enroll. LEVEL has taught us how impactful this particular baseline characteristic is on drug response in these patients. We set the ceiling for the baseline walk at 450 meters, which has been the ceiling for all of the successful PAH trials. But capping the walk at 450 allowed less advanced patients to be enrolled. Our median baseline walk came in about 50 meters higher than in HELP and roughly half our population based on that measure of severity and several others associated with it in our prespecified analyses ended up being patients healthy enough that the placebo arm improved on its own.

In this one aspect, the study design permitted the inclusion of patients with moderate disease. The learning lies right there. We did not fail to find a treatment effect in LEVEL. We diluted one. Stuart will show you exactly how. Stuart?

Thank you, Chris, and good morning. LEVEL was the largest randomized controlled trial completed to date in PH-HFpEF. As Chris summarized, this study has already taught us several important things nobody knew a month ago. I'm going to take you through all of it, including the prespecified subgroup analyses that elucidate the route we intend to take to bring levosimendan to the many patients who will benefit. Let me begin with trial design. The LEVEL study was a Phase 3 double-blind, randomized, placebo-controlled trial. 41 sites in the United States and Canada randomized a patient. 241 patients were randomized 1:1.

Dosing was an oral capsule, 1 milligram twice daily for 4 weeks and then 1 milligram 3 times daily through week 12. The primary endpoint was change in 6-minute walk distance at week 12. Patients completing the double-blind period were eligible for an open-label extension of up to 2 years, which is ongoing. Every patient underwent a right heart catheterization and had to meet qualifying hemodynamic criteria, either at rest with passive leg raise or with bicycle exercise. That was our enrichment strategy, and it came directly from the hemodynamic profile of the patients who responded to intravenous levosimendan in HELP.

So while we enriched on hemodynamics, based on that evidence, we had no basis to enrich the minimum or maximum baseline 6-minute walk distance, which I will come back to. Baseline characteristics were broadly balanced. As you see on the slide, mean age 69, 71% female, BMI 33, 72% were on an SGLT2 inhibitor, 28% on a GLP-1 receptor agonist, 60% on an MRA and 87% on diuretics. These are the drugs that have shown benefit in patients with HFpEF and are considered the standard of care. 45% were NYHA Functional Class II and 54% were functional Class III.

This was a contemporary well-treated HFpEF population, which is what we set out to enroll. 60% qualified on provoked hemodynamics rather than at rest. Now as to the baseline 6-minute walk distance, 319.5 meters with a standard deviation of 85. The median is 333 meters. I'm going to come back to the 333 number many times. The primary endpoint, patients on levosimendan improved their 6-minute walk distance by least squares mean of 14 meters at week 12. Patients on placebo improved by 10.4 meters. The treatment difference was 3.5 meters with a standard error of 7.3 and p-value of 0.63.

Using the mean, patients on levosimendan improved by 17.7 meters compared to 9.8 meters for patients on placebo with a treatment difference of 8 meters. The key secondary endpoint, KCCQ Total Symptom Score did not reach statistical significance. Levosimendan improved 6.6 points and placebo 6.5 points with a treatment difference of 0.1 points, standard error of 2.2. NYHA Functional Class improvement was 24.1% on drug and 22.5% on placebo. Adjudicated clinical worsening events were evenly split with 3 in each arm.

Now on to safety. The oral form of levosimendan demonstrated a favorable safety profile in this population. Adverse events occurred in 86% of levosimendan patients and 72% of placebo patients. Treatment-related adverse events were 38% against 17%. Discontinuations due to an adverse event were 8.3% against 1.7% and dose reductions were 15 against 4. The following effects are characteristic in previous studies with oral levosimendan, headache, palpitations and hypotension. They were largely mild to moderate, and they were manageable, and they were handled mostly by reducing the dose rather than stopping the drug.

Serious adverse events, 10.8% against 10.7%. Adjudicated clinical worsening events, 2.5% in each arm. On arrhythmia, among patients with no pre-existing evidence of atrial fibrillation or sustained ventricular tachycardia, there were no new events detected during the randomized phase with repeat Holter monitoring. There were 2 deaths during the double-blind phase, both in the levosimendan arm, both unwitnessed, both determined to be unrelated to the study drug by the patient's physician. To remind you, the annualized mortality rate reported in HFpEF populations of this age and severity is on the order of 15%.

Those are the topline results and allow me to show you exploratory endpoints and prespecified subgroup analysis. These are the findings that give us confidence that there is a clear path forward to a successful Phase 3 program and approval. The biologic thesis behind this program is that levosimendan's potassium ATP channel activation mechanism reduces the chronic constriction of the vessels in the splanchnic circulation. This constriction leads to volume overload and dilating the splanchnic circulation will lower the patient's central and pulmonary venous pressures. This reduces strain on the heart and lowers pressure in the lungs.

Those patients whose pressures are going down would be expected to demonstrate this through improved exercise. New evidence in this trial not only proves that thesis, it demonstrates an impressive and what we expect replicable treatment effect. NT-proBNP is a highly reproducible measure of cardiac wall stress. This is called strain on the heart, I just mentioned. Levels of this protein were markedly elevated at baseline in our overall population as expected. We observed a 49% reduction in the patients treated with levosimendan compared to placebo, which was robust. This biomarker is not a subjective measure.

It correlates with the severity of heart disease and pulmonary hypertension in a multitude of studies and is trusted by physicians for diagnosis and treatment. A treatment effect of this magnitude has been associated with improvement in outcomes and is a reliable indicator of treatment efficacy. A treatment effect of the magnitude of levosimendan in LEVEL is larger than any I have seen in a large HFpEF trial. What about pressures in the lungs, as I just mentioned. We measured with echocardiography, the right ventricular systolic pressure or RVSP, also sometimes reported as PASP, Pulmonary Artery Systolic Pressure.

But just realize this is the pulmonary artery pressure that you are used to seeing in pulmonary hypertension trials. We observed that the PA pressure was reduced with levosimendan by 3.6 millimeters of mercury, whereas the placebo patients had an increase of 0.5 millimeters for a treatment difference of 3.5 millimeters of mercury, which was also robust and with a nominal p-value of 0.005. In patients below the 333-meter median at baseline walk, the PA pressure dropped 4.9 millimeters, nominal p-value of 0.009. The pulmonary vasodilators that have been approved for Group 1 PH demonstrate the similar reductions in PA pressure in those patients.

Lowering pulmonary artery pressure is the most important biologic objective in a therapy for pulmonary hypertension. Population studies in patients with pulmonary hypertension have showed a reduction in the pulmonary artery pressure is associated with a survival benefit. A paper published just this week by Zile and Lindenfeld and others demonstrated that a 3-millimeter mercury reduction in the PA systolic pressure delivers a 20% reduction in heart failure hospitalizations. The fact that levosimendan was able to markedly reduce BNP and reduce the pulmonary artery pressure with this drug in this population is a critically important finding.

When we look to have a better understanding of which patients benefited most from levosimendan, we first look at the baseline 6-minute walk distance as a measure of disease burden. The lower the walk distance, the higher the disease burden. Our first step was to look at those patients who walks were above and below the median, which was 333 meters. And those with a 6-minute walk below the median in blue on this slide, the treatment effect was 26.3 meters with a 95% confidence interval and nominal p-value of 0.0112. However, when we looked at the patients with a baseline walk above the median baseline in red, the final 6-minute walk distance in the levosimendan patients showed a treatment difference of negative 17.6 meters.

So here's what's happening. The drug is helping sicker patients more. What we became aware of in this population is that patients who were less sick and on background therapy did not show treatment benefit from 3 milligrams daily of levosimendan, but those with a higher burden of disease were very responsive despite being well treated on the latest recommended medical therapies for HFpEF with a very meaningful clinical response. The 6-minute walk test was reliable in conveying to us the patients with Group 2 PH respond best to this drug.

Look by age in the oldest quartile above 74, the difference was 37.6 meters, 95% confidence interval and nominal p-value of 0.0013. Look at the confidence interval there in the older patients in this trial, in patients at or above the median age of 71, the difference was 27.1 meters, 95% confidence interval, nominal p-value 0.0021. This compared with patients below the median age of 71, the difference was negative 19.2 meters, 95% confidence interval, nominal p-value, 0.0972. This finding about age persists whether we look at median tertiles or quartiles. We also look at natriuretic peptide as a biomarker of disease burden. The higher the BNP, the more severe the patient.

Patients who came in above the median baseline NT-proBNP improved 16.7 meters against placebo. It is the same a gradient again arriving from a completely different direction of a blood test rather than a walk test or a birthday. Thus, these 3 markers of disease burden, exercise capacity, age and natriuretic peptide point us to our responder population. I remind you, these are nominal p-values. They are not adjusted for multiple comparisons and the multivariable work that is still running, but they do provide answers to questions that were specified in advance rather than derived from data review afterward. There is a practical finding sitting inside this that I don't want anyone to miss.

A 6-minute walk distance turns out to be both our endpoint and our best tool for selecting patients. We do not need to go and find a new biomarker to identify who responds. We need to take this measurement at screening and use it to decide who gets into the trial. We relied on change in 6-minute walk as a solid primary endpoint in our studies, and these results confirm its trustworthiness. The biologic measures of improvement parallel the clinical efficacy benefits and the results bearing this out.

So in summary, we believe that levosimendan has now proven itself as a safe and effective therapy in patients with PH-HFpEF who have more disease burden. In those patients who had lower baseline walks, NT-proBNP was higher to start with, and it came down dramatically on therapy. This very impressive clinical treatment effect demonstrated here is of a scale we trust would satisfy regulatory authorities for product approval. There was not enough HFpEF literature to rely on when refining the upper range of this criteria. We also had to rely on PAH literature.

Remember, in any HFpEF study, many of patients have PAH that may not be described. So it's very difficult to tease out in these databases how much the pulmonary hypertension versus the HFpEF is driving walk response. We just don't have a trove of successful Group 2 trials to guide us. On the other hand, in PAH, FDA guidance suggests drug developers use a range of 165 to 450 meters, and that guidance draws on libraries of successful PAH trial databases. So in Group 2 PH, we now have a very clear indication where to set the ceiling.

The Tenax team is exploring now whether an amendment to the ongoing LEVEL study would generate a data package that when submitted to authorities will bring this therapy to patients. Keep in mind that LEVEL 2 was sized based on the safety database requirements and is already powered above 90%, even with the 55 standard deviation and an assumed dropout rate more than 4x what we saw in the shorter trial. LEVEL randomized 241 subjects. LEVEL 2 currently aims to enroll more than double that number.

We are optimistic about our ability to modify this trial once regulators have reviewed our LEVEL results and heard our proposal so that we can generate a successful data package and get this drug to needy patients. And with that, I am very pleased to introduce Dr. Sanjiv Shah. Sanjiv, we would value your thoughts about the meaning of these results.

Thank you, Stuart. It's really a pleasure to be here and discuss my thoughts on the trial result as the academic principal investigator of the trial. I've been taking care of these patients for the past 25 years and in the past 20 years directing the Northwestern HFpEF program. And as you are well aware, this is the dominant form of heart failure now. We think that based on the current data, 60% of patients in the United States alone have a preserved ejection fraction greater than equal to 50% at the time of diagnosis. And of those, we think that 75% to 80% have pulmonary hypertension.

So it's extremely common, and there are no approved therapies for PH-HFpEF. So of course, for the past 2 decades and longer, we've been looking for drugs that can improve this patient population, and it's been littered with neutral trials or even some trials that harm the patient. And it's been a really challenging patient population. We have had successes recently with SGLT2 inhibitors, GLP-1 receptor agonists, nonsteroidal MRAs, and that's been a great advance. And some may say, well, maybe we don't need to do anything more for HFpEF. But clearly, we do.

Even in these trials, even on patients with all of these medications, they're still quite debilitated and they still have high morbidity and mortality. And those who develop pulmonary hypertension and the more severe the pulmonary hypertension is are the ones that really suffer and the ones that need the most help. Now in the past, we have tried with pulmonary vasodilators to see if we could help these patients with PH-HFpEF like we've helped patients with pulmonary arterial hypertension. And it's been a universal no, not an improvement at all. And what's consistent about all of these trials is that NT-proBNP didn't come down.

In fact, it either stayed the same or went slightly up on the treatment. This is the case for drugs like [ BOL ] and relaxin in the recent trial that was published last year, PDE5 inhibitors with endothelin receptor agonists, sGC antagonists and sGC stimulators. And so there's a clear signal there that there is not an improvement of congestion. There's not an improvement of wall stress, and those trials were neutral and didn't improve the patients. Now we look at the recently published CADENCE trial, which was in patients with a pulmonary vascular resistance of greater than 4, which is quite high and is the minority of patients with PH-HFpEF, but we do see those patients that are quite sick.

And the CADENCE trial did reduce PVR and seem to improve other markers, including NT-proBNP came down, but not nearly as much as we see here with levosimendan, which is a much easier to administer oral medication that seems to be better tolerated. So while I felt that 6-minute walk distance, if we could show it with this number of patients in a wide proportion of patients with PH-HFpEF sort of a broadly defined patient population, we would have a major advance. And sometimes we get lucky and it's easy and it's simple. Here, what we saw was what we often see in HFpEF that it's not simple, that it is a heterogeneous patient population.

And what we see here is that sicker patients really are the ones who benefit. And that's the most important finding because those are the ones that we need to treat. If we have a patient who has a 6-minute walk distance of, let's say, 375, 400 meters, 425 meters with PH-HFpEF, they're doing pretty well. And we have treatments for those patients. We have SGLT2 inhibitors. We have GLP-1 receptor agonists, nonsteroidal MRAs. And those are not the patients that are having the events that -- like heart failure hospitalizations and higher mortality.

So the ones that we want to treat are the ones with the lower 6-minute walk distance with the higher NT-proBNPs in the sense that those are the ones that are at highest risk for heart failure hospitalization and death -- those are the ones that are costing the health care system so much and are really the ones where the disease of HFpEF and pulmonary hypertension is driving the patient's journey. And in those patients, in particular, is where we found the benefit in the LEVEL trial, those with the lower 6-minute walk distance, those with the higher NT-proBNP.

And so I think that these findings, while they're not a slam dunk and an easy win for us that will quickly move us forward on the path, I think that what they show is actually better than we would have expected. Based on these data, I feel like we have evidence here that levosimendan will reduce heart failure hospitalizations in PH-HFpEF. And I say that because of the reduction in NT-proBNP. There's sort of a linear relationship across all trials, not just the big large outcomes trials, but all trials that have looked at this.

And that linear relationship suggests that the reduction in NT-proBNP that we see here, which by far is the biggest reduction in NT-proBNP in any PH-HFpEF or HFpEF trial ever done will reduce heart failure events dramatically. And of course, that needs to be proven. We need to do that trial. But to me, that is really compelling. You couple that with the fact that those with a 6-minute walk distance at baseline less than 333 meters did quite well, 26-meter improvement compared to placebo. I think it gives us the whole package there, and it tells us that this drug really has a future. I'm still a big believer in the drug, and I've done many of these trials in HFpEF, and I take care of many of these patients.

We see that in the open-label extension that patients feel well and are doing better. And so I'm still quite positive about the drug and think that we really have a lot of work cut out for us, but I'm very positive and hopeful for our patients based on the results that we've seen here today. Thank you.

Thank you very much, Professor Shah. I know that in a few minutes, we'll have questions, and we'll probably be directing a few of them to you. We appreciate your support, but we are also reminding everyone that there will be data coming out in the future in publications and in presentations, and we're not going to steal too much of your thunder here today. So we're looking forward to hearing more about that linear relationship between BNP and heart failure events, but we'll wait for the late breaker, et cetera. So all right. So with the last few minutes of the call, we want to do 3 things: tell you what we know now, tell you what we are going to do about it and tell you what we cannot answer yet today.

What we know? We have a drug candidate that lowers filling pressures and pulmonary pressures in this disease at a dose we no longer have questions about with a safety profile consistent with over 25 years of clinical use in study. We have an efficacy signal above 26 meters in the patients who aren't walking near the normal range, and we have several ways to identify those patients before they enroll. The question that kicked off the PH-HFpEF program at Tenax in 2018 was what might levosimendan do in a totally new group of heart failure patients without a drug and with high unmet need. Numerous HELP findings led us straight into Phase 3.

In LEVEL, a question so many of you asked was whether oral levosimendan at the 3-milligram daily dose would transfer those benefits. That question is now retired. What is left is a trial design problem and a new challenge our team will overcome to deliver this drug to patients. Trial design is the kind of problem we know we can solve, and our aim will remain shortening the time patients have to wait. I want to be clear about that 26-meter signal because I worry it will get lost beneath the headline. 26 meters is not a rounding error we are trying to talk our way into. It showed up in the patients who have the most to gain.

It moved with 2 independent biological markers that dramatically improved in this population, and it is about the same magnitude HELP produced in about the same kind of patients. In the patient with highest indications of disease burden and LEVEL, we saw effects in the 30- to 40-meter range. The RVSP and BNP improvements are profound. Those improvements are evident across all quartiles of levosimendan patients we studied, and they are undetectable in the placebo patients. We have pressure tested these observations already with the data we have so far, and I can tell you our pathway is very clear.

So what are our next steps here? Tenax will request a Type C meeting with FDA to present these findings and our recommendations. We are seeking in parallel scientific consultation from EMA. We will go into these meetings with a complete data set, including the multivariable analysis we don't yet have and with our Scientific Advisory Board and regulatory advisers aligned behind the recommendation. Our specific experts are working on the right strategy to construct criteria for an impressive LEVEL 2 based on several disease severity factors they and the medical team are analyzing now.

Their goal is to create a correlated set of factors, preserving as much of the population as possible on the way to a positive result. They will avoid overfitting by using modeling techniques that repeatedly test our rich new LEVEL data set through these filters. Tenax's statistics leaders inform us we have strong evidence undergirded by impact on BNP that is clearly translating to exercise improvement for designing a successful next trial. The predefined analysis reveals demonstrable levosimendan effects in those with higher disease burden at the start of the study. The prespecified analyses consistently show this positive effect.

This is not exploratory. I should pause for a second here to thank the incredible data management team at Medpace and the biostatistics team at Lucent who've worked tirelessly to get us where we are this morning. Dr. Shah plans to present the LEVEL results at ESC, where the community will next learn quite a bit more about LEVEL, and then he and the steering committee intend to continue presenting and publishing their findings. But one thing I will commit to this morning, something that doesn't require a validated stat output or a regulator's input, we are not intending to enroll another patient into this program whose baseline 6-minute walk distance fits in the range that diluted LEVEL.

In the COPD, heart failure and PAH literature, there is an association between a walk of less than 350 meters and increased mortality. In ATTR cardiac amyloidosis, a walk less than 350 carries a 2.2-fold higher mortality risk. There is plenty to support lowering our ceiling to something in this range. So we're finalizing the exact threshold quickly based on our new LEVEL data. And when that number is fixed in the coming days, the steering committee will communicate it to every active LEVEL 2 site.

Now what can I not tell you today? We have yet to decide whether the right vehicle is simply an amendment to LEVEL 2, which is enrolling now or an amendment and the addition of another trial built from the ground up for this population. Several options are under consideration. We may limit the walk ceiling or we may create a combined disease severity score to avoid enrolling patients who are a few years ahead of the point in disease progression where levosimendan is going to help them.

Amending LEVEL 2 preserves what we have already built, initiated sites around the globe, a highly functioning group of national lead investigators are running supply chain, delivering IP, training, ethics and site approvals and randomizations. A continually building footprint is active across 4 regions. A trial population built on the findings of LEVEL could enroll at a reasonable rate, and we would not be starting from scratch on site activation. These are key decisions that we're going to make with the FDA rather than ahead of them and not on today's call, a few days after we were unblinded.

We believe the agency will see that oral levosimendan does what we said it would do at a dose we know is driving big improvements in patients who heart failure physicians clearly recognize in their practices and who our sites will now identify before they ever enroll and with an effect size larger than the one we powered LEVEL to detect. The FDA wants therapies for the millions of Americans suffering from PH-HFpEF. The data we have shown you this morning tells us what needs to get done.

We intend to develop and ultimately deliver an authorized oral levosimendan to these patients because this drug has proven itself to us in our data. To everyone at Tenax, thank you and keep going. To the investigators and the coordinators, thank you. We are very grateful to the patients making this research possible. So thank you for listening. And Betsy, we will take questions now.

[Operator Instructions] The first question today comes from Olivia [ Saunders ] with Cantor.

What is your best explanation for why those higher baseline patients, a the third and fourth quartile on walk score are seeing such a pronounced worsening effect versus placebo? And is that something that you also saw on KCCQ scores? Or is that just a 6-minute walk distance phenomenon? And then I also wanted to ask about how each arm did in that lower disease burden patient population and whether those patients on TNX-103 actually saw a decline versus baseline 6-minute walk or whether the placebo patients maybe just improved disproportionately or maybe it was some combination of both?

That's a great question, Olivia. I'm going to hand over to a great set of questions. I'll hand over to Stuart. Let me just mention to everyone a couple of things. The Tenax team was unblinded by our SA team last week. So we have been pretty much heads down through today with our effort to get the data where you saw it so that it's in front of you and everything is clear. So there are going to be detailed questions we can't answer.

There are also going to be a really important conceptual conversation topic like the one you just brought up that fit in that category. But if we can't be certain here today that we can quickly lay our hands on accurate data, we may punt on a few of those things. Second, again, please remember that sort of analysis is a great is a great question for the SAB to answer in upcoming presentations and published topics. So it's an open one. I'll hand it off to Stuart here and then maybe if Sanjiv has comments on those topics. So it's KCCQ, it's the patients with the highest walk at baseline who seem to go the wrong direction.

Thanks, Chris. So Olivia, that's a lot of questions. Let me kind of go through one at a time, and I may have to ask you to repeat some of them. You have to imagine the one thing that I focused on right from the get-go was why the ones who were less sick and received levosimendan did so poorly because we have convincing data that they were taking the drug, and we have convincing data the drug had a biologic effect on their BNP.

In this population, where these patients have congestion, we talk about the preload effect on the heart and lungs, which means the blood volume coming to the heart and lungs in these patients. And as you know, we talked about our mechanism being to reduce that blood volume. There is some literature suggesting that in these patients, if you reduce the blood volume too much, they actually develop worsening symptoms. And it's a term preload insufficiency, which is relatively new and being talked about a lot in the literature.

But to come up with something that makes sense, and I'm not saying this is actually going to pan out, is that the drug worked too well in these patients. It dropped their preload to a point that they didn't have enough filling. And again, if you don't have enough filling, that will limit your ability to walk. So that fits the drug's mechanism. It fits the disease and may turn out to be the answer to the question. But as we've already alluded to, our drug would not then be the ideal treatment for these patients at this time. If they get worse over time, then it's a different story. Okay. Next question, Olivia.

Very helpful. Yes. And then the other question was just around KCCQ scores, whether you saw maybe more pronounced benefit on KCCQ scores in those patients that do have the higher baseline 6-minute walk or higher disease burden, however you all are categorizing it?

But here's what we'll tell you about KCCQ at this point along the lines of the topic you just raised. One of the things that we can do in looking at the patients in each group on each treatment over time and their responses, which right there, you know you're talking about a multivariable analysis, right, is also look at their KCCQ and see it in those patients that Stuart just described, who we may discover here were not preload dependent et cetera, that their KCCQ expresses what their walk expresses. We know that the patients in that group who walk high at baseline. Well, you know what, let me ask Sanjiv. Sanjiv, what do you -- are you still there? And do you have a theory on this?

Yes. I mean -- so first of all, they are great questions, and we still have a lot of work to do to analyze all of this. But I would say a few things. So first of all, I think what Stuart said is very possible. The patients who walk far at baseline and have lower filling pressures, they are a different type of patients, and they may sort of depend a bit on the sort of blank vasoconstriction during exercise to help them get to that walk distance and you remove that or you lessen that and they can't do that.

So that's something physiologic that we'll have to figure out and take a look at. But also, the -- when you look at the quartiles, the 95% confidence interval at the higher end of walk distance, levosimendan versus placebo, I think, crosses unity and so like we're not as confident at that higher range as we are at the lower range, where it is very much the confidence intervals don't pass and you see a very statistically significant improvement. And I think the last point that you made is sort of like is the issue that these patients are really worsening? Or is the issue that the placebo is getting better?

And from my analysis of the data, that last is seemingly what's going on, where the -- that it's not that levosimendan is harming these patients in some way. I mean it's just that these placebo patients, when they're already doing quite well, they kind of did a little bit better over time. And is that a fluke or something? I don't know. But in the ones with the lower 6-minute walk distance, those are the ones that where it really does seem like there's a clear improvement on levosimendan. So I think there's still a lot that we have to unpack here. And I'm hoping that by the end of the month, when I present it at ESC, we'll have a lot more of these answers.

The next question comes from David Risinger with Leerink Partners.

Regarding Slide 13, do we need to wait for ESC to understand the absolute figures behind the calculation so that we can assess to what degree the above median and below median performance was driven by the placebo responses? That's my first question. And then I have another one, please.

So we'll try to go to 13. So I think people will remember it's the blue and the red walk bar graph. Dr. Shah can address it in a second. Let me address it in one way, Dave, it's a great question. Let me just share a little bit of the observed data over time that sits behind this bar graph, right? What we're looking at is 12-week data. Let me give you the walk distance in observed data. This is raw data, not statistically adjusted, et cetera, but these are just the numbers that we have at 4 weeks, 8 weeks and 12 weeks.

In the Levo patients below the median baseline at entry into the study, the improvements are 19, 21 and 27 meters, right? They went up to -- they're on 2 milligrams, they walk 19 further. They go up to 3, they go to 21 and 27. Do they stay there? Do they go up? Do they go down after week 12? Your guess is as good as mine. We, of course, have the OLE data. What about the placebo patients who walked less than the baseline? Their walks are negative 1, 4.8 and negative 3, a tight clustering of unimpressive numbers.

The same trends are available in different analyses, and that's part of the data that we're looking at initially here that points to the same conclusion that, that's our the buyer. So Professor Shah, we're not showing all the data behind this now because we're still getting through it. But what would you expect one will see, I think.

Yes. I mean I think that's right. It's not that the patients who benefited -- like let's look at the lowest quartile of baseline 6-minute walk distance. I think the question that we just heard is, is it that the levosimendan patients are truly doing better? Or is it that the placebo patients in that group are just doing a lot worse and we're preventing worsening. It looks like the levosimendan-treated patients are actually doing better, which is really kind of amazing to see because a lot of times when we have really sick patient populations like ATTR cardiomyopathy, we're just sort of preventing are slowing, worsening.

But here, I think we're seeing an improvement. And again, we've got to really dive into those data and tease it out. But that's what Chris had just mentioned. That's what we're seeing. Placebo remains flat and the levosimendan group improves over those 12 weeks.

And then just a follow-up. So with respect to LEVEL 2, -- how many patients have been dosed in LEVEL 2 to date? And what do you anticipate FDA and EMA's receptivity will be to a protocol amendment? And Stuart, could you remind us about FDA's historical advice on a required p-value to file with a single successful trial?

So as in the past -- great question, David, and we'll answer 2 of the 3. As in the past, we've not disclosed information like where we are with enrollment. As far as the -- what do I anticipate the FDA's susceptibility is to our arguments. One is wise not to do that. We believe that when they see our data, we'll be in good shape. So Stuart, why don't you take on the last question there about the previous discussions on p-value.

So David, the guidance that we have an agreement with FDA for LEVEL for the program was they would agree to a single trial with a p 0.01 endpoint or 2 trials at p 0.05. As you know, we sought the latter for several reasons for our program. And a lot of it had to do with the resources because, as you know, when we had a big raise, we just started the second trial right away. So I think the question on mind is what the FDA will now say regarding our program, and it's too early for us to comment. We've been talking internally about it. We have some very prestigious FDA advisers on this. And so we're confident that we will come to them with a very compelling program.

I'll give you one more piece of information that came from stat on the weekend. Just looking at -- based on the new data we have, looking at the powering calculations of LEVEL 2, with the dropout rate being higher than we anticipate it will be with the standard deviation of even 55 and a treatment effect like 25, we're well above 95% power with the size of that trial. All right.

The next question comes from Yasmeen Rahimi with Piper Sandler.

Do you know if the baseline 6-minute walk test correlated whether patients were enrolled via exercise or are qualified via rest?

Okay. We'll go one by one that way. Here's what we'll tell you. We have started looking at this issue that has been discussed a lot in the last couple of months of whether the position of the patient that qualifies them for the trial might have biased us, et cetera. What we have seen so far tells us that our criteria are fine. So we've got a lot more digging there to do, but it's a good question.

And then second one, I think Dr. Sanjiv you've noted, right, like when we look across the subgroups that levosimendan had a profound improvement and the improvements were not due to placebo, but just drug effect when you broke down the 6-minute walk test based on quartiles. I guess that raises the question, would you have on hand what the nonplacebo-adjusted 6-minute walk distance benefits were in that post-hoc subgroup analysis that you broke down among quartiles?

No, we're not sharing that at this time yet. I think we just need more time for that. A good question.

And then maybe the last one is team. I know you're working diligently to figure out what the new cutoff is going to be for the 6-minute walk test. But have you had a chance to look at LEVEL 2 where you are in regards to total number enrolled and what their median looks like? And if you did pick 333, what percentage of the patients would be in that? I don't know if you've done that exercise yet or not.

I think your question is a lot like Dr. Risinger, right? Like where are you going to do the cut to get the impact you want, et cetera. The data is there. We will not have a problem with quantity of reliable data, but we will also not rush into it. I'll remind you guys that in LEVEL, early in the trial, we decided we would amend the protocol to require at least 90 days on therapy with GLP-1s or SGLT2s. We implemented that through an immediate action so that it stopped happening, and it worked.

And months later, sites continued enrolling and they basically stuck to the new requirement in the protocol. So we can do the same thing here on the walk distance. In other words, it can be a very rapidly implemented change that will show up in the future amendment, but the investigators listen to the steering committee on a topic like that. So we're in good shape.

The next question comes from Seamus Fernandez with Guggenheim Securities.

I was hoping you could give us a little bit more color on what you hope to show at ESC in particular, not in terms of the data, but the subset analysis. It seems to me like we'll need to know a lot more information with regard to the prespecified analysis above and below in terms of the baseline drug characteristics and the patients that were on the different potential drugs that could impact performance. Obviously, we got a little bit more information in terms of the placebo performance as it relates to the below 333. I guess the question is, did the patients on placebo improve in the upper bound group? I'm sure everybody is very interested in all of that.

But it seems like baseline characteristics in terms of the patients on drug or perhaps even mid-trial, although only 12 weeks drop in could also play a role here. And then just also wondering when you sort of run the statistics, against multiple comparisons, things like that. I know that, that's challenging given the fact that these were not statistically significant results, but it seems like it's necessary to add in statistical evaluations of multiple comparisons here just because there are factors that come into play. So when we see that p-value of 0.01, how statistically valid is that prespecified analysis?

Okay. Good. Thanks, Seamus. I'll hand to Sanjiv in a second. I'll say just very quickly though, there's sort of 2 things you do when you get your topline results. We've got the full analysis set and you immediately start asking for the ad hoc data you want next. So you think and you wait. A lot of the things you've asked about are in the topline data set. What we've really shown here today are prespecified analyses. So there's a lot there already, but you still have to think about it, right? And so 2 weeks between now and ESC is quick. So Sanjiv, can you respond to some of those topics and at least give folks an idea of what they might see at that time based on what you and your co-authors want to do in that presentation?

Yes. Well, I just want to temper expectations. I think we get like 8 minutes in total for the entire presentation. So a lot of it is going to be what you see here today. We just don't have enough time to go through everything, but the papers will have it. And we are well underway of writing papers on the primary results and NT-proBNP. And I suspect that we will do a deep dive in the baseline 6-minute walk distance categories. So I think in the next few months, hopefully, you'll see -- start seeing those publications come out. We're too -- we got the results too close to the meeting to do a simultaneous publication.

But I think given the interest that journals will be picking this up to publish it. I think that the multiple comparisons question is fair. And that's the reason why we prespecified the number of subgroup analyses we are doing for the primary endpoint, which is in the statistical analysis plan. And so we can go ahead and control those subgroup analyses for multiple comparisons. And if we do that, just based on what we've seen so far in terms of the interaction p-value for that baseline 6-minute walk distance, I think it will stand up to that. But that's something that we and the statisticians have to calculate still.

Thank you so much, Professor Shah. Is there another question? Operator, have you got any other questions? I'm not hearing from Betsy. Are you there? It looks like we've lost our operator, and that may make it hard for us to hear questions. So just give us a moment here to try to keep connected. It looks like an IT issue is being worked through at the conference center. So it may just take another few seconds. We know we'll also be talking with 2 or 3 of you later today.

Can answer questions there. All right, folks, it's a Monday just after 9:00 a.m. I know how busy you are. Our operators aren't able to get on. So I think we've lost the ability to talk with you here. Sanjiv, thank you so much for your being available this morning. I know you're heading out to an academic meeting. So we will look forward to talking to you folks in the future, and thank you very much for joining the call today.

Thank you.

Good afternoon, and welcome to the Tenax Therapeutics Virtual KOL Call. [Operator Instructions] Please note, today's call is being recorded. I'd now like to turn the call over to Chris Giordano, President and CEO of Tenax Therapeutics. Please go ahead.

Thank you, Betsy, and welcome, everyone, to an in-depth discussion of the science behind Tenax's ongoing development program in PH-HFpEF. We're developing TNX-103, an oral formulation of levosimendan, which we believe has the potential to be a first-in-class treatment for PH-HFpEF. TNX-103 is currently in late-stage development in the Phase III level study with top line data expected in the second half of 2026 and also LEVEL-2, a global Phase III study on track to initiate this year.

Tenax is not alone in focusing on patients with the most common form of PH for which no drug is approved. And it's great to see more and more investigational strategies being evaluated in these patients, considering the grave unmet need that patients with PH-HFpEF face. At Tenax, we get a lot of questions about the differences between our PH-HFpEF program and work done in the space by other researchers. For example, we focus on a different physiologic target than other drugs in development. We have a unique mechanism of action and aspects of our trial design designs are really different to other PH-HFpEF trials, et cetera.

So we thought we'd spend an hour today. We thought it'd be good to dig into these differences and explain that these differences are intentional. Demonstrate they're grounded in established science and a deep understanding of the disease and of this patient and hopefully build your understanding of why these differences could be important. Also, we thought it would be good to provide you a viewpoint on these differences from experts outside the company.

So before I introduce our speakers today, I'd like to remind everyone that we'll be making forward-looking statements during the event, and please review our disclaimer shown on the slides. Today's discussion will be led by Dr. Stuart Rich, Chief Medical Officer of Tenax. Stuart is joined by Dr. Barry Borlaug, Professor of Medicine and Cardiology at Mayo Clinic; and Dr. Sanjiv Shah, Director of the HFpEF program at Northwestern University's Feinberg School of Medicine. So Stuart will present viewpoints on these key issues that we face when addressing the PH-HFpEF and then moderate discussions among these experts before we open the lines at the end of the call for live Q&A.

So I'll now hand over to you, Stuart, to begin the panel discussion. And thanks again, everyone, for joining us.

Thank you, Chris. So I'm going to start with the topic of volume overload. The question that we often get is, isn't it accepted that excessive blood volume in the heart and lungs of patients is a cause of PH-HFpEF. So the title of this slide is the title of a paper that was published by Milton Packer, one of the most renowned KOLs in heart failure history. And it's entitled Impaired Systemic Venous Capacitance, the neglected mechanism in patients with heart failure and a preserved ejection fraction. This was published in 2020 right after we had published the results of our Phase II HELP study and the assessment of the mechanism of action of levosimendan.

And as Dr. Packer points out, it's not something new. It's something that's been neglected. And in the paper, when he discussed the dominant phenotypes of patients with this disease, the hypertensive phenotype and the obese phenotype, he acknowledges that venous blood volume is increased in both of the phenotypes. If you're not familiar with what we mean when we talk about excessive blood volume in the venous circulation, take a look at this lady's neck vein. It's markedly distended and it's filled with blood. It's almost like a monometer telling you that the pressure in that vein is quite high. The blood volume is so high that it's not only distending her vein, it's overloading the right side of her heart, her lungs and the left side of her heart at the same time. This is a fundamental problem in HFpEF and in PH-HFpEF.

So to try to explain to you the physiology, if you look on the left side of this slide of a healthy person, you will see at the top, there are lungs, then there is the heart and then there's a splanchnic reservoir. Splanchnic refers to the abdominal organs, which consist of the liver, the spleen, and the small and large intestine. It has a very large blood supply and actually holds about 30% of all of the blood in your body. It's a reservoir because it's there for when you need it, just like gas in the gas tank of your car.

And so when you are sleeping at night, your physiology kind of looks like this. The reservoir is filled. The lungs, not so much because you don't need a lot of blood in your lungs to take up oxygen while you're sleeping. If you're one of these people who jogs in the morning, when you get up, you need the extra blood volume so that you can run, you get a signal from your sympathetic nervous system to constrict the blood vessels in the splanchnic reservoir, kind of like squeezing a sponge and getting more water out, that blood will go into your heart and then into your lungs and then into your body with more oxygen.

The arrow drawn next to it going in two directions tells you that all day long, this is going on in you. But depending on what you're doing, there are times when you're resting and the blood volume is in your abdomen and times when you're running and the blood volume shifts into your heart and lungs. On the right side, however, is an illustration of what happens in patients with PH-HFpEF. And here, if you look at the lungs, the lungs are totally full and totally full all the time.

Splanchnic reservoir, however, is constricted and not entirely filled. And this is why you see that lady's neck vein being so distended because so much blood is coming out of the reservoir into her neck, into her heart and her lungs. And we've drawn this large arrow to show you that it's kind of one way, which means that this is continuous happening all the time during the day. And thus, our goal is to try to change this abnormal physiology of PH-HFpEF and restore it back towards a healthy physiology. So let me stop here and ask our experts what their thoughts are about this mechanism. Sanjiv, why don't you start?

Thank you, Stuart. Yes, I think that this is something that's been around in our sort of history of physiology since the 1960s and '70s is sort of this excessive splanchnic blood volume. And it's something that I think was forgotten for a long time until it was resurrected about 10, 15 years ago and people started getting interested in again because we started noticing with implantable pulmonary artery monitoring like CardioMEMS and others like it that you'd see a phenomenon that was different than what we thought typical.

So I think in doctors' minds, we think, okay, heart failure patient, they have a high -- maybe they're eating a lot of salty food. They're eating too much fluid. They're not taking their medications and all of a sudden, over weeks and days, they slowly have a buildup of volume and then they get hospitalized for heart failure. But once we had these implantable hemodynamic monitors, what we saw was that it actually happened a lot more abruptly than that in many cases. So it wasn't this gradual increase in body weight or something like that or pressures. It was an acute rise in pressure, let's say, in the pulmonary artery in the case of CardioMEMS. And it was that acute volume load that led someone to a hospitalization.

So it was the shift of blood volume from the splanchnic to the chest and to the heart and lungs that were stiff that seem to be causing it. And so there's sort of two things. I would agree with you that this can cause, I would say, an exacerbation or worsening. I mean the primary thing that's going on is you have a congested or you have a remodeled heart. You have a stiff heart muscle, you have maybe elevated sort of remodeling and elevated resistance in your pulmonary artery. So there's disease there. That -- but the disease people can live with. It's the fact that then the body has this excessive splanchnic vasoconstriction, excessive blood volume that's going to the chest that it can't handle. And that's what causes the symptoms. That's what causes the heart failure hospitalizations. That's what causes the exercise intolerance. And so by reducing the load on the heart and the lungs, patients can feel a whole lot better.

Barry, do you want to add to that?

Yes. I mean, obviously, this system exists, it's evolutionarily selected for. This has a teleological use. So in the example here, on the left, that's at rest. We have this going to the right that instead of being PH-HFpEF, the bottom part at least could be like a normal human like in the setting of stress. So when you jump up and try to run away from a tiger that's chasing you, your autonomic nervous system is activated and you get venoconstriction in all the veins in the splanchnic reservoir. So it goes from being on the left to the right. I mean that's what we need in order to enhance blood return to the heart so that the heart can then rapidly pump that blood out to the body. So this is a good thing.

But the problem in chronic heart failure is chronic heart failure, including PH-HFpEF, is associated with pathologic chronic elevation of that autonomic activation. So those veins are just constantly constricted. That's because our bodies aren't -- we didn't evolve to live through heart failure. These mechanisms are there to help us in fight or flight stress systems. But when you activate these pathways chronically, you get this excessive venoconstriction and then you're squeezing all this blood into a heart that, as Sanjiv points out, is stiff, cannot accommodate that increase in blood. So you're just making it much worse. So essentially, the body's so-called adaptation or what I think it's doing as an adaptation is making the disease much worse. And we think that, that's an important therapeutic target.

Thank you, Barry. So going on to the next question regarding proof of concept. Is there data that shows reducing the blood volume in the heart and lungs of patients with PHFpEF will result in hemodynamic improvement. So I'm going to show you some proof-of-concept slides of things that were done. The first one was a mechanical approach to pre-load reducing devices. Pre-load and volume load should be considered the same thing. And what they did is they took catheters with balloons on the end. The one on the left is an SVC balloon that stands for superior vena cava and partially occludes the major vein coming into the heart from the upper body. The experiment on the right used the IBC, inferior vena cava and inflated a balloon into the major vein going in the heart, receiving blood from the lower part of the body.

But what they showed with the SVC balloon experiment, which was to inflate the balloon and let the patient lie there for hours to see what would happen is a dramatic reduction in the pulmonary wedge pressure shown in blue and the right atrial pressure shown in red over time. On the right side, they wanted to look at the effect on rest and exercise. And so they kept the balloon up while the patients were exercising and then noted also that during exercise, there was a fall in that right atrial pressure, pulmonary pressure, but no change in the cardiac output that is necessary to be able to perform the exercise.

Building on to that, the Duke University Faculty said that if, in fact, this is the sympathetic nervous system triggering this, can we block the ganglion that controls splanchnic circulation and maybe treat it that way. And so the illustration on the left shows that they take a spinal needle and put it into patients and inject lidocaine, which will paralyze that nerve for about 6 hours. And the hemodynamic results are shown on the right. This is data from rest and exercise right heart cath. So if you look at the right atrial pressure screen, you're seeing baseline data in blue, nerve block data in red, and the conditions that they are measured is lying down with their legs flat, their legs up, exercising and then stopping exercise.

So what you see is the right atrial pressure, which is normally about 5, markedly elevated before coming down dramatically at rest and exercise. Similarly, if you move to the wedge pressure, normal should be about 10, you're seeing a dramatic elevation in wedge pressure before coming down substantially with the nerve block. But important to point out, the ability for the heart to pump normal amount of blood, the cardiac index was not negatively impacted. So this is the science behind our development of levosimendan, a drug that has site-specific venodilatation properties on the splanchnic circulation.

And so in our Phase II HELP study, we had two parts, the first of which was based on mechanism of action. Patients came in for a rest and exercise heart cath, we hospitalized so they could receive an intravenous infusion of levosimendan for 24 hours and then came back to the lab the following day so that we could see what kind of changes existed in the filling pressures of the central venous pressure and pulmonary wedge pressure. Same format, you see the baseline pressures in blue and the treatment pressures in red, legs down, legs up and biking. And you can see dramatic falls in all three conditions in these patients.

Interestingly, all of the patients that were in this study, we targeted the peak increase in wedge pressure as the primary endpoint and 85% of the patients enrolled in that trial responded to a reduction in the exercise wedge pressure, the first time that has ever been demonstrated. Then we took the data from this with the volumetric data obtained with simultaneous echocardiography and Dan Burkhoff in his laboratory was able to compute the blood volume changes. And what you're seeing, levosimendan on the left and splanchnic nerve block data on the right, that it was a reduction in that blood volume that was accountable for the hemodynamic changes we saw. Barry, what do you think about this data?

Yes. I mean I think that this is a good model, which explains what we saw in the trial. And we didn't see a lot of other effects in terms of contractility and that could -- or diastolic function that could account for the observed hemodynamic benefit. So this really does point to more of a venodilator effect, which we think is key for all the reasons that we articulated in the earlier slides.

Sanjiv, your thoughts?

Yes. Well, we've learned a lot from studies in HFpEF. And I want to contrast what we saw in the reduced LAP-HF2 atrial shunt trial, and that's where we're actually increasing load to the right side. And then the sort of the Axon rebalance trial where we're doing the splanchnic nerve block and level and what we see there. And so what's interesting is that if you just block the splanchnic nerve or you give a pure venodilator like nitrates. And of course, nitrates have a lot of other properties that may not be good in HFpEF.

But let's just say the splanchnic nerve block when you do that, you're reducing pre-load, you're reducing the very thing we're talking about. But it didn't -- in the trial, we did rebalance, it actually seemed to not work very well in patients with pulmonary hypertension. And the reason I think is because the -- you're just dropping the nerve and you're not doing anything else. We know that levosimendan has other properties. And I think it was supporting the right ventricle.

Normally, if you reduce blood volume with exercise, your cardiac output can go down. Now the right atrial pressure in our patients in the HELP trial was very high. And so you often don't see that. But we can't argue with the nerve block results. On the other hand, with the shunt, when you increase blood to the right side, the ejection fraction goes up. And so I think that my personal opinion is levosimendan doing two things. It's sort of relaxing the blood vessels in the splanchnic, but also supporting the right ventricle, so it doesn't respond poorly to that, especially during exercise.

So I would have expected that we might have seen a slight reduction in cardiac output with what -- if it was just venodilating the splanchnic vasculature, but the fact that the cardiac output maintained and was constant, I think, is a sign that this is really the best of both worlds. And I think that's why it works so well in this patient population.

I think another point that's specific to patients with pulmonary hypertension, and this is a little bit more complicated and not really shown in these slides. But they have the right heart and the left side of the heart compete for space. And in these patients, a lot of times, the right heart is very dilated and it squishes down on the left heart. So the pressure in the left ventricle, which is what causes fluid to build up in the lungs is high, but the left heart itself is small and underfilled. So a little bit of reduction in blood coming back to the right heart can paradoxically improve the left heart filling, and that can offset any potential reductions that you might see from this.

I think the other key difference between this strategy and the splanchnic nerve block is that -- I mean, you're killing the nerve. It's only one nerve, but it's gone. Whereas this is just kind of taking the top off. Splanchnic nerves can still fire with like a drug that causes venodilation. So it might be a little bit better tolerated, too. That's another alternative explanation. This is all -- what we're saying here is speculative. We don't know at this point, but this is what we believe.

Great. Thank you for that comment. All right. Now we are often asked how has the Phase III level study been derisked to assure a positive outcome. So there's three points I'd like to make. The first one is that the Phase II HELP study that we did confirmed that levosimendan produces a reduction in wedge pressure with exercise in these patients. The illustration for those unfamiliar shows a patient lying on a cath table with a mounted bike. And when we talk about rest and exercise right heart cath, that's kind of what it looks like.

The hemodynamics on the right side of this slide actually come from Dr. Borlaug in a paper that he published. And what he elegantly demonstrated is that patients without HFpEF and normal wedge pressures at rest have very little increase in the wedge pressure when they exercise. But those patients with HFpEF shown in red, have a dramatic increase in their wedge pressure with exercise because they are unable to handle that increased volume loading at the time. If we are doing a clinical trial where our primary endpoint is going to be a measurement of exercise capacity, we felt it was essential to know what the hemodynamic changes would be when our patients exercise. To my knowledge, no other study in PH-HFpEF has ever provided supporting exercise hemodynamic data the way we have.

Secondly, we've enriched our Phase III trial based on the hemodynamic profile of the patients in the Phase II HELP study that responded to the drug. And so we're kind of assuring ourselves that the patients we're enrolling are ones that have the best opportunity to have a favorable response to the drug. The hemodynamics are shown on this slide. At rest, they must have a wedge pressure of 18 or higher, a mean pulmonary artery pressure of 30 or higher that goes to 20 and 32 with leg raise and 25 and 35 with exercise. These are very high pressures. It's a sick population with intention.

Finally, I want to point out that all of the level data that preceded the trial came from the use of intravenous levosimendan. The patients in the HELP study got an infusion of levosimendan once a week, knowing that the drug would wear off as the week went on. The active drug is this metabolite 1896. And when we did our 6-minute walk assessment after 6 weeks, it was done towards the end of the week when the level of 1896 was low, and we received a 29-meter treatment effect, which was considered remarkable, in fact, the only positive study in this group of patients.

We then are going to an oral formulation, as you probably know, in our Phase III program. We have legacy studies with oral levosimendan administered chronically for over 6 months in patients with heart failure and 12 months in patients with ALS, and that has provided us with a great amount of data on the optimal daily dosing, the efficacy and safety of the trial. So one would assume that if the patients now are taking daily drug, with a therapeutic level of drug, they would respond better to the oral rather than the IV.

We did a transition study of the patients who were in the open-label extension of the HELP trial on IV therapy for up to 2 years, who all wanted to take oral levosimendan in its place. And as we had anticipated, they would feel better, walk farther and have better cardiac output and the results of that transition study showed 6 of 7 positive improvement in symptom domains of the KCCQ and additional improvement in the 6-minute walk of another 7 meters and a measure of the natriuretic peptide down 23% over the level from the IV therapy. Sanjiv, what do you think of this?

I think the graph show it all. I mean I think that it really seemed to dramatically reduce and improve hemodynamics. It also improved exercise capacity and did what we thought it was going to do. I think if you're not doing the studies and you're not in the room when this is happening in these multicenter studies, exercise invasive hemodynamics is really kind of messy. I mean it's like the patient is moving around, the catheter is whipping all over the place, and it's really hard to show a benefit.

And so the fact that we saw these reductions in the hemodynamics, especially when we were thinking about when was this repeat right heart cath done, it was like a trough level of when the levosimendan IV was getting infused. And then on top of that, we see that the patients transitioning to oral did even better, I think, is really quite fascinating. I mean I didn't -- I have to say like I was worried that you go from IV to oral and what we saw in the patients was really remarkable.

And so I do think that it's active, and we're hitting what we typically don't. I mean, it's very difficult to improve 6-minute walk distance on -- in HFpEF. I mean GLP-1 receptor agonists have done it. We had one trial with an SGLT-2 inhibitor that did it. It was called PRESERVED, the rest of it didn't. But these are like 20-meter increases. I mean we had more than that here in a sicker population, which I thought was remarkable.

And sometimes you'll see like a fluke, these are small studies, even though it was randomized, you might see a fluke, maybe there was an outlier here or there. But I mean, we had -- it wasn't just that there was like a random 6-minute walk distance improvement. There was real hemodynamic improvement, and it was more pronounced in the stress blood volume and it was more pronounced at low levels of exercise, which is what -- where patients live. So I think it's a small randomized trial, but it really set the scene for where we are now with LEVEL-1 and LEVEL-2.

Barry, you're one of the highest enrollers in HELP and one of the highest enrollers in LEVEL. So what's your sense from the patients that you've enrolled in these trials?

Well, I think patients love it. I don't think. I know they do. I think it's really telling that for the IV formulation, I mean, patients had to get -- they had to have a PICC line, like a permanent IV line placed, which is associated with infection and clots and things like that, and they had to get an infusion once a week, real pain in the butt. And as Sanjiv points out, the levels would decade just until as the days elapse and you get closer to your next dose, it would kind of wear off. And despite all that, they were just dying to remain on the medicine because it was really helping them to feel substantially better.

So the fact that we now can do this with a pill is incredible. And as this Slide 15 shows that even above and beyond the IV, the pill was not only maintaining the benefits that we saw in the acute trial, but actually improving upon that. And in the LEVEL study, there is an open-label extension. So even the patients that received placebo initially have an opportunity to get the real drug, and it's really been life altering for many people. And I've participated like Dr. Shah, we've both been involved in a lot of different clinical trials over the last 20 years in HFpEF. But I would say that the effects that we're seeing here that the patients are telling us are really, really impressive.

So now I want to discuss pulmonary vascular resistance or PVR. We are asked, is the change in PVR an appropriate hemodynamic endpoint to measure drug efficacy in PH-HFpEF because we do not use PVR as a meaningful hemodynamic measure of efficacy. So for those unfamiliar, the pulmonary vascular resistance cannot be measured directly in people. And so as a surrogate, this equation was developed back in the 1950s, which is derived from the mean pulmonary artery pressure minus the mean pulmonary capillary wedge pressure divided by the cardiac output. And so the PVR is considered lower is better.

And so you can lower the number overall if the cardiac output goes up, and/or if the pressures come down. So this slide kind of is meant to show you why the PVR can go in the opposite direction that you would consider it to be a useful representative. It has been used in the Group 1 PAH trials, and it seems to be helpful. However, I want to remind everyone that the wedge pressure is normal in those patients and doesn't change. So if you look at the example on the right, I've chosen numbers that are kind of really realistic numbers that we see in patients, a baseline PA pressure of 40, a wedge pressure of 25, and a cardiac output of 5, that computes to 3 wood units.

If you want to make your endpoint lowering PVR after treatment with a typical pulmonary arterial vasodilator for Group 1, what you will see is a drop in the mean PA pressure and an increase in the cardiac output. The wedge pressure may stay the same or may even be higher. And in this example, you see a typical hemodynamic effect with the wedge pressure from 3:1 going down 60%, and this is an adverse response in this disease.

Look to the example on the left. This is an example to represent what we've seen with levosimendan, same baseline hemodynamic numbers, 3 wood units. After treatments, we dropped the wedge pressure from 25 to 15 upper limit of normal, maintain the cardiac output and lower the PA pressure. Now the PVR computes to 4 wood units, you would say, hey, you increase your pulmonary resistance by 30%. Is that bad? And we would say no, it's actually a very good treatment response. Barry, what do you think about this?

Sorry, I had trouble getting off mute there. Yes, I think that this is -- for this very reason, this can be misleading here. A high wedge, we think a high -- the wedge pressure, of course, is a surrogate measure of the left atrial pressure, and that's the proximate cause that leads to the lung congestion, water accumulation in the lungs. And if that goes up, that's exactly the opposite that we want to achieve in patients with heart failure and preserved ejection fraction. So I think this example is illustrative in that way.

Sanjiv, do you have some thoughts?

Yes. I mean I think that it boggles my mind because we -- of course, I work on all these trials with all these companies. And two things just drive me crazy. One is this hyper focus on the pulmonary vascular resistance, and I've told them all that because the right ventricle compared -- I mean, what it cares about either at rest or exercise is, I think, the total load. Like what's the total load it's seeing when it's trying to contract? And what is that total after load? And it doesn't care if it's the PVR or it's -- what part is coming from the left atrium pulmonary veins. It's all the -- it's sort of the total load.

And so separating out the PVR makes sense, like you said, when you have a very low wedge pressure in pulmonary arterial hypertension, but doesn't make sense at all when you have pulmonary venous hypertension or a combined post and precapillary. So there's so much more that's important that we don't focus on. And I think in the patients, what we see is, obviously, what we really care about is do they improve their exercise. I mean, their ability to do things and their 6-minute walk distance, their excise capacity. And what that usually translates to is that they have -- they're decongesting and lowering the PVR doesn't necessarily mean that.

So I just -- I think that there are better ways. And the other thing is it really boggles my mind that we don't do exercise more. We're not like trying to see what -- I mean, these patients are really symptomatic with exertion. So if we don't do exercise or some sort of maneuver to see what happens when you're stressing the system, then you're going to totally miss out. I mean the splanchnic vasoconstriction, that typically happens when the patient is under stress and either they're exerting themselves or some other stressor. And so if they're just lying there, you're doing your study at total rest, you just won't see it. So those are the two innovations, I think we see here in the LEVEL trial that makes it different than every other pulmonary hypertension development going on.

Go ahead, Barry.

Yes. I mean I think just to expand on that, I mean, this is the concern with using isolated pulmonary vasodilators in patients with HFpEF because you're basically unlocking the screws to let more blood go through the lungs, and it's going to go to a left atrium that already can't accommodate that. So if you're not treating the high left atrial pressure at the same time, and Stuart is, I think, going to show some of the examples of pulmonary vasodilator trials in HFpEF. I think we really need something that's going to lower that left atrial pressure. And that's really shown nicely on this Slide 18, the difference between the good and the bad scenario.

Okay. So by the way, you're setting me up pretty well, Barry, for the next question here. We are going to just quickly give you our views about other clinical trials in PH-HFpEF, as Chris acknowledged from the start, there are other companies actively pursuing treatments, and we applaud that. The question that we're asked is about data showing that pulmonary vasodilators or relaxing analogs in PH-HFpEF will result in hemodynamic or clinical improvement.

So currently, there are three trials ongoing that are including patients with PH-HFpEF. That one is the CADENCE trial with sotatercept, which is an FDA-approved pulmonary arterial vasodilator. One is a relaxin analog being developed by Tectonic called the APEX trial, and one is a relaxin analog being developed by AstraZeneca called the Re-PHIRE trial. All three studies enroll patients based on a standard definition of PH-HFpEF without enrichment, meaning that all they need is a mean PA pressure above 20 and a wedge pressure above 15.

My concern here is just that this sets themselves up for misclassification of some of the patients because the definition of PAH would be a wedge pressure of 15 or less and Group-2 PH, a wedge pressure of 16. And the fidelity in many cath labs with the fluid field catheters may not be able to discriminate correctly those two separate groups. In addition, as we just reviewed, all three of these studies have designated a reduction in PVR at rest as the primary endpoint. All three drugs also have as a mechanism of action, a pulmonary arterial vasodilator. There have been now six randomized clinical trials in the approved pulmonary vasodilators for HFpEF and all of them have failed.

So I want to kind of go a little deeper into this as Barry kind of set me up as to what is going on as why they're getting a bad result. So this drawing, I did to show what has been called protective pulmonary arterial hypertension, something that was clarified way back at the time we had mitral stenosis as a cause of pulmonary hypertension. So I'm going to talk you through the drawing. You see RV stands for the right ventricle. P is the pulmonary artery. That pulmonary artery goes into the capillary next to the alveolus. We call that the alveolar capillary interface. And this is where oxygen, the O2 is -- this is where oxygen is exchanged from the lungs into the capillary bed. That blood flow then goes into the pulmonary venous side, which is the capital letter P and then the left ventricle.

And so patients with PH-HFpEF have an enlargement in their left atrium because of the very high pressures in the left atrium. Those pressures will move backwards and start to injure that very precious interface, we call the alveolar capillary interface. And the net result is oxygenation is difficult. That is a threatening biologic signal to the survival of the person. And so the body does its best to try to come up with an adaptive response to protect against that injury. And the adaptive response is number three, constriction of the pulmonary arterial bed. The constriction of that bed limits the blood going from the right ventricle and pulmonary artery into the pulmonary vein and does its best to prevent that elevation in the wedge pressure, especially with exercise, which goes ahead and injures that interface again.

If your drug treatment is targeting #3 to dilate the pulmonary arterials, as Barry alluded to, more blood will start going into the left atrium that wedge pressure gets higher and the injury gets worse. So these are the results of two trials that were presented this year that were unsuccessful in HFpEF. It just so happens our KOLs were the PIs in the trial. The macitentan trial is known as SERENADE and the volenrelaxin trial is known as HFpEF. What I've demonstrated are the outcomes curves that were published in those manuscripts, and I'm going to let the authors of these papers talk to you about them themselves. So Sanjiv, what can you tell us about the SERENADE trial?

Yes. Well, we thought we were clever, and I have to say I thought it was a valiant effort. We know that endothelin receptor antagonist do cause fluid retention. We also know endothelin is a major player in heart failure and pulmonary hypertension. So we wanted to try to design a smart trial that maybe would take advantage of this. And what we based that on was the fact that it seemed like in early trials of endothelin receptor antagonist and heart failure reduced CF, if patients did not have congestion at rest and they had more of -- they weren't fluid overload and they didn't have increased fluid in response to endothelin receptor antagonist that they could do better.

So we designed the trial with a run-in period for 4 weeks on placebo, then 5 weeks on macitentan, everyone got it. And if they developed fluid overload or were unstable, they were out. And then we randomized them. And as you can imagine, it was a very hard to enroll trial. And yet, as you can see, I mean, it wasn't statistically significant, but the signal is certainly there. Macitentan, despite all that, was still ineffective and in fact, worse. It still caused the fluid overload despite everything we did. So that really was the nail on the coffin for me. And when I'm thinking about it, and we'll see what Barry has to say about volenrelaxin and I'll let him talk about that one.

But what I think happens with a lot of these medications is that there's a neurohormonal response. So there's -- it could be a direct drug effect. It could be the fact that the body is responding to that hemodynamic signal with trying to retain fluid, probably a little bit of both of that. I think the problem with endothelin receptor antagonist is that they cause increased capillary leak, but also a lot of fluid retention at the level of the kidney. And we know that endothelin blockade itself basically goes to the cardiomyocyte natriuretic peptide, NPPB and NPPA promoter region and shuts off natriuretic peptide. So if you block the endothelin receptor, your body is going to think that it needs to lower natriuretic peptide gene expression. So that's not good. So there's many reasons. And I think that's why that doesn't work. And I think any drug that's a pulmonary vasodilator, you have to really kind of look at what other ill effects it might be having.

Barry, can you shed some light on the volenrelaxin trial for us?

Yes. So relaxin is a peptide hormone that's made by the placenta, and it's a vasodilator and it's responsible for a lot of the adaptations that happen in women when they're pregnant to support the fetal circulation. And there were trials years ago of IV relaxin in acute heart failure, and it showed a lot of evidence of positive benefits, including hemodynamic benefits with decreases in PVR and decreases in left atrial pressure and pulmonary artery pressure. But it's IV, so it can only be given for a couple of days. That led many different companies, including Eli Lilly, who made volenrelaxin, but others, as Stuart pointed out, with active compounds to try to engineer a longer-acting formulation of relaxin.

So that's what we tested in patients with HFpEF, and we're very hopeful based on the acute responses that had been previously shown with IV relaxin that we'd see a benefit. But unfortunately, as you can see here, we did not. This is just an exploratory safety analysis here, but this is showing a 2.6-fold non-significant increased risk in heart failure hospitalization in patients who were with HFpEF were treated with volenrelaxin as compared to placebo. And it wasn't just this. We saw the signal through multiple other metrics. We saw decreases in hematocrit indicating dilution of the blood from water overload and worsening congestion.

We saw an increase in NT-proBNP level, which is a biomarker that's reflective of fluid status. Patients were less likely to have an improvement in functional class, it was really a consistent bad message across the board. So again, it's the same point that Sanjiv was just making. A lot of times, some of these drugs that dilate can have other untoward effects that promote volume retention and you end up shooting yourself in the foot. So I think that's been a big concern for these and other studies that have looked at other drugs like PDE5 inhibitors have also shown evidence for either neutral or for harm that is a different kind of pulmonary vasodilator. So I think we need to be clever, and I think we are being clever with levosimendan through its distinct mechanism of action.

So I do want to thank both of you for shedding your brilliance over these topics. I'm going to now shift back to the operator for an open question-and-answer session. Thank you so much, guys.

[Operator Instructions] The first question today comes from Dave Risinger with Leerink Partners.

I apologize about the background noise. So thank you very much for the very detailed presentation and for sharing all of your perspectives and insights. I have two questions, please. So I'm going to go out to a little bit higher level. First, could you talk about the requirements for FDA filing and whether an accelerated filing might be possible after you collect additional safety data in 2027 before the LEVEL 2 trial reads out later in the decade. It would seem to me that, that might be possible, obviously, depending upon the magnitude of benefit, but considering the unmet need.

And then second, could you talk a little bit about the method of use patent protection, which appears to me to be very solid, but I think it would be helpful for you to characterize why you think it will be fully blocking and the duration of that protection.

Okay. So regarding accelerated approval, it seems very attractive. And one might argue, given the fact that this is a serious, potentially fatal disease with no treatment, it would depend on the effect size of the LEVEL trial. A very robust improvement would be a powerful stimulus to -- for the agency to consider this, but you also need to remember about the requirements for a safety database. And even though this drug has been used in 20 countries for 25 years and has an excellent safety record, the use has been short-term IV for heart failure.

So I can't speak for the agency, but my sense is they really want a robust safety database because there are so many patients who may end up taking this drug due to the fact that it will be oral and effective. So David, I can't really -- I don't really have a sense at this time. I think we'll wait for the level trial readout and then we can have some discussions and get a better sense to that. But at the present time, at least from the company side, we're anticipating going through both trials and then submitting at that time.

Now regarding the patent status, we have four patents. The patents are method of use patents. They essentially patent the label. So they're indicated for HFpEF, PH-HFpEF, they're indicated for any formulation, IV, oral, subcu, et cetera. They run into 2040 and with a patent extension would give us another few years on top of that. We have been told from experts who've looked at that those patents seem to be very solid. So I think our patent estate is pretty strong here.

And then just a follow-up, could you just articulate briefly why the patent estate is so solid for method of use patents?

Well, it covers not only levosimendan, but levosimendan with other drugs. So if someone were to get an indication of HFpEF or PH-HFpEF, it's extended over both, that would be a violation of the patent. So that would limit competitors only to development of a drug for PH-HFrEF, if you wish, or HFrEF by itself. And that I think is what -- is where we're focusing. We are not even trying to say that we're going to look at any other features of this heart failure community other than HFpEF and PH-HFpEF. And as I say, because of the multiple patents, which covers routes and doses and combinations, we think it's very strong.

The next question comes from Yasmeen Rahimi with Piper Sandler.

Thank you so much for the detailed discussion from Dr. Borlaug and Dr. Shah. Wonderful to hear your voices on the call. A few questions. I think the first question was how patients are feeling really well when they were part of the HELP study. So I just want to get a view on, as Dr. Shah and Dr. Borlaug, you're involved in the LEVEL-1 study, you're seeing the same phenomenon on patients feeling and functioning better or expressing that. Obviously, you don't know who's on the therapy. But if you could maybe voice over your commentary that you're seeing so far, that could be really helpful. That's sort of question one.

Question two is we often get is given that there is -- we went from an IV dose to an oral dose in the LEVEL study, a lot of investors try to understand the switch between these formulation if it could introduce any variability or any -- I guess, help us understand sort of like the translation and feeling confident that the change still predicts a high probability of success. And then the third question is to Dr. Borlaug. Do you have a good grasp on whether the difference or relaxin, as you know, Lilly has one that they discontinued, Astra has one, and Tectonic. How do these constructs differ? And is it more about patient selection? Is it the biology? Appreciate any color there.

Okay. So let me -- let the first one go to Dr. Shah because Dr. Shah also was an enroller in HELP and has been a very active enroller in LEVEL. So Sanjiv, do you want to share your feelings about what the patients are telling you?

Yes. I mean it's kind of phenomenal. I mean -- so you're right, we are blinded for the first 12 weeks, but then the patients undergo a few weeks where they go a washout and then they go into the open-label extension. So in the LEVEL trial, we now have a lot of experience of patients being on the open-label drug. And we always have to remind ourselves that there's potentially a placebo effect and they're unblinded. We are all unblinded when they go on open label. But we see things we never see in trials unless they're like positive in a positive way. Like -- so sure, when you unblind, you do see a bump up in patients who feel better now that I'm on the real thing. But what we've seen, which is really interesting is we saw patients who felt better during the randomized phase and then they go -- they wash out for 2 weeks and they feel worse again, and then they start feeling better again.

So I think that this is kind of what we saw when we did the IV to oral transition in the previous HELP trial. So it's very promising. I mean I'm not going to pretend that there's -- that this is definitive by any means. But I have to say, I mean, it's rare in patients with HFpEF, especially PH-HFpEF, where they're really debilitated, that anything makes them feel better. So that is -- it's quite different than other medications we've seen in this patient population.

So regarding the transition to oral, we have a lot of legacy data, including a MAD study that identifies what the level of the 1896 is associated with the oral dosing. And an early MAD study suggested somewhere between 1 and 4 milligrams a day would be the ideal. We then have a lot of chronic data on the metabolite from the two long-term oral studies, knowing at what level we would kind of want to target in the patients that were in the health trial.

When we did the oral transition, we up-titrated from 1 to 2 to 3 milligrams a day over 2-week intervals and measure those metabolite levels as well. And so seeing comparable levels of metabolite at the levels that we would anticipate to be therapeutic is giving us the confidence that we have the right dose. There is no problem from the metabolite because the levosimendan itself is highly well absorbed. And the metabolite is predictably produced in these patients reaching steady state over 2 weeks.

So we really feel from the PD/PK standpoint that we have hit the ideal dose. The dose also is a little higher than was used in chronic heart failure studies before because the patients weigh more. And remember, IV is weight-based where oral is standardized. And so we wanted to cover that potential gap as well. And Barry, do you want to answer her question about relaxant?

Yes. I mean, first, just to expand on some of the earlier, we -- some of the stories are just really outrageous. I mean people that have been like converted to becoming totally sedentary, men are out there in the fields, shooting dear and dragging the buck carcass all the way back to their truck and stuff like that. And women just telling me these stories that they're just life and day, just really life altering, that word is used.

And as Sanjiv says, I mean, we're unblinded in the open-label extension, but I mean, I can't tell you how many times people have said, I'm feeling a little worse because in the open-label extension, you go back down to b.i.d. dosing, twice daily dosing before you go up to 3x a day. And they'll say, I'm feeling a little worse than I was a couple of weeks ago, but I'm still better than the start of the trial, and then they get back up to 3x a day and they're feeling better. So it really -- again, it's -- you've got to always take it with a grain of salt when it's unblinded and the placebo effect is real. But really, I mean, it's quite convincing to me.

In terms of relaxin, there are different formulations. They have different pharmacokinetic properties. They're attached to different molecules that allow for the longer half-life, basically, so that you can give it once a week. But fundamentally, this is all human relaxin. Every one of these different molecules is human relaxin. It's not like some kind of close receptor agonist. It's just relaxin that's attached to like in the Eli Lilly compound, a formulation of albumin. So I just don't -- I don't think it's going to be that much different.

Now some of the companies, I think, are using different dosages. It's possible that could be different. We'll see. And the patient population in the volenrelaxin trial, we enrolled patients with a recently decompensated state. We did that because we thought that would have the best chance of success. Relaxin also improves renal blood flow and we thought GFR, and there was a signal for that in the trial. And we know that patients with recent hospitalization, that's a really sodium avid state, meaning those patients are very congested. They're really holding on to sodium. So we wanted something that would improve kidney function and reduce that sodium avidity or that proclivity to sodium retention. So we thought that, that was the right choice.

In the end, it might have allowed us to see a signal a little easier by selecting that patient population. But I think if the drug is worsening congestion in anybody with HFpEF, yes, if you take somebody who is ambulatory, far away from the hospital, they're going to have more reserve to handle any sort of volume accumulation that you would get from a relaxin, assuming that's what is doing, but it's still not going to be a good thing. And eventually, I would imagine that it would promote volume retention. But we'll see. We have to look at the totality of the evidence. There'll be more data coming soon. I'm really [Technical Difficulty]

I think we lost Barry.

Are you still on?

I'm still here. I just finished -- I don't know if you heard what -- I kind of ended on and I'm excited to see the other data when it comes. We'll see.

[Operator Instructions] The next question comes from Matt Phipps with William Blair.

Thanks for the very comprehensive walk through PH-HFpEF. Dr. Borlaug and Shah, just curious, what do you -- what would be your expectations for a patient on placebo, not treated with anything for like a 6-minute walk decline over a 12-week period? And then similarly, like what would be a level of 6-minute walk benefit that would get you excited? I mean there's obviously plenty of anecdotes, I guess, to get you excited, but just on that point specifically, maybe.

I think a decline -- I mean, there's always going to be a little bit of noise, especially with small sample sizes and individual patients are like five patients, you may see some people that just decline and it's just sort of noise. That's why we have to do larger trials. So we kind of eliminate that noise and we can see the signal. I think -- what level gets me more excited? I think like a 20-meter improvement would be really phenomenal. That would be something that I would consider to be very, very significant. If it's more than that, then the enthusiasm just continues to grow. But I'd say at least 15 to 20 probably would be what I would be looking for.

Yes. I think we have to think about it differently than pulmonary arterial hypertension, where the standard has been 30 meters because like even GLP-1 receptor agonist which caused a tremendous amount of weight and did a lot to help these patients in both the STEP-HFpEF and SUMMIT trials, it was only about 20 meters. And so here, we're not -- the patients aren't losing a ton of body weight, which plays into 6-minute walk distance a lot. And so 20 meters, I think, 15 to 20 meters would be really remarkable. And that's the kind of improvement that we see and patients are like -- they really feel it and they tell you about it.

I think that interesting thing happens, I think in most HFpEF trials and heart failure trials, there's a bit of a placebo effect and patients just being better when they're in trials. So their 6-minute walk distance, their KCCQ, the lower it starts out, the more it kind of improves during their -- even if they're in the placebo group and stuff like that, we see that -- but in PH-HFpEF is the most severe form of HFpEF. And you do see in severe disease, you see progression and you see progression of RV failure over time in HFpEF.

So it's conceivable that there are patients who, like in transthyretin cardiomyopathy, they're actually worsening. They're in the part of the disease state where they're actually -- no matter what you do, they're worsening. So you sometimes get very sick patients like that. But I think the majority of worsening even on a placebo is what Barry was saying, like you get these patients, they might come in one day and they're depressed or something, their spouse passed away or something. And these are real things that happen. So I think that's why we always push for adequately powered larger trials to make sure that what we're seeing is real.

That's really helpful. And kind of on that front of the PH-HFpEF versus HFpEF, I get some questions from investors when they're looking at this space of the SGLT2 class or recent approval for none. I mean, obviously for HFpEF and I guess, some different definitions there. But do you see those playing a role in this patient population? Would this be something you'd use on combination with levosimendan? Just curious if there would be any overlap.

Yes, I think definitely. Sorry, Sanjiv, go ahead.

No, I think we're going to say the same thing. You'd use this on top of those. I mean they're totally compatible and those are sort of standard of care and finerenone is really, I think the data is best for like -- in terms of it being better than spironolactone or eplerenone is in lower GFR as lot of these patients have cardiorenal syndrome. So yes, we'd use it on top of those.

The next question comes from Seamus Fernandez with Guggenheim.

This is Colleen on for Seamus. Maybe first, I was wondering if you could talk a little bit more about any learnings from the REBALANCE trial that might relate to LEVEL. Are there any differences in the patient population or trial design we should all should be thinking about? And any concerns with hypotension? And then secondly, can you talk through how or why over-indexing on the HELP study not achieving stat sig on the primary endpoint is likely flawed and the difficulty of that endpoint?

Yes. I mean I can take the first one. The Axon trial, when we were designing it, it was like I mean it was a totally revolutionary like going in there and ablating the splanchnic nerve. We really didn't know who it was going to help. I mean there were reasons why we thought it might help people at the earlier end of the spectrum of HFpEF, the so-called exercise-induced left atrial hypertension, where the pressures are normal at rest and go way up with exercise.

And then there were reasons why we thought it would help patients like those we enrolled in help with very high right atrial pressures, PH-HFpEF, maybe CpcPH because they also have very high RA pressures. And so you're reducing the -- we thought we might be reducing the resting sort of splanchnic vasomotor tone and things. And I think -- so if you want to think about differences, it was that the HELP patient population was a subset, same with LEVEL, it's a subset of a more broad population that we enrolled in the REBALANCE trial with AXON.

And what we saw there is something that is really, I think, to me, apparent now that I've done all these trials and I think about it when I see the patients in clinic. There are some patients who are pre-load insufficient. So those patients are -- they -- and COVID can do this autonomic dysfunction, diabetic neuropathy, Parkinson's. It's basically like they're the patients who -- they've got this syndrome, but they can't get out of bed without feeling lightheaded and dizzy. Their right atrial pressure is normal usually. They're not the HELP, they're not the LEVEL patients. They're not the ones that we want.

Then there's patients who are preload dependent, meaning that if you don't do anything else and you just drop their preload, they're going to feel like crap. They still might have a less number of hospitalizations for heart failure, but they're going to feel like crap because they depend on their preload to augment cardiac output to fill a very stiff ventricle and you're not doing anything else for them. And then there's the final group, which is a large group. I mean it's what I call the preload overload. And that's what we were studying in help.

And that's the kind of patient who has a very high right atrial pressure and they're kind of -- they've got way too much preload and reducing it with levosimendan helps. But even if they were sort of edging into that preload dependent state where they're like got a sicker right ventricle, that's what I was talking about earlier. I think that levosimendan is doing other things to improve right ventricular function and in that way, has some advantages over things like splanchnic nerve ablation.

So I'll address the question about the endpoint issue in the health trial. So for those not familiar, we identified the drop in pulmonary wedge pressure during peak exercise as the primary hemodynamic endpoint for the health trial. So we were faced with several challenges. The first one is that intravenous levosimendan had never been given to anyone outside of an intensive care unit. And here, we were giving it at home to patients with a home infusion pump and a permanent IV line. It would require the patient to be homebound for a day.

We knew that the half-life of the active metabolite was about 4 days, but we didn't know what kind of carryover effect we might be able to anticipate by giving it once a week versus twice a week. Going back and forth, we thought twice a week would be difficult for the patients to adhere to, even once a week asking that to doing was tough. And so we had -- and we did not have any access to oral. So we planned it thinking that if successful, we would go with IV into the Phase III trial. Agency would want to see trough levels from the IV to see about efficacy. And so the design was to give it once a week IV and measure their hemodynamics and 6-minute walk at the end of the week.

Now what you've heard from both Dr. Shah and Dr. Borlaug is that many of these patients were very sensitive to the dose that they were getting in that when they were on the 2-milligram dose, they were less robust, a little more shorter breath, which improved at the 3-milligram dose. So I think it's no surprise that at the end of the week when we did the 6-minute walk, and the hemodynamics that even though the wedge pressure at rest and with legs up, which is a stress, had the same effect, it diminished itself when it went with peak exercise.

And I attribute that to the fact that they didn't have enough drug on board. So we don't look at that as a failure of the drug. We look at it as part of the design of the trial that allowed that to emerge. We also did a mixed model assessment of the wedge pressure at 6 weeks with rest and exercise, and it was highly significant there. But the data is the data, and we don't hide from it. I think what the data just educated us to is that we needed a drug that had longer-acting efficacy and the oral was the solution.

Yes. I'd add on that the data quality can be a little worse during exercise. Patients are -- they're breathing heavy and heart rate is fast. They're breathing rapidly. It makes it a little bit more difficult. So just the signal is maybe a little bit clearer at rest when they're totally relaxed and then feed up, they're still relaxed. They're still breathing normally. So that also might have contributed to the inability to see the effect. But I think that's a lesser effect than the fact that the drug was at trough levels, like Stuart mentioned.

Although it was interesting, Barry, that the central venous pressure was the same at exercise. It had the same treatment effect. So it kind of tells you, I think, that it's the left-sided wedge pressure that's the hardest target to treat, which we thought going in.

This concludes our question-and-answer session. I would like to turn the conference back over to Chris for any closing remarks.

Thank you, Betsy. Thanks, everyone, for joining us today, especially Dr. Shah and Dr. Borlaug, who took time out of your extremely busy schedules. And thanks to all of the questioners. We really appreciate the thought that you guys have given this. So the goal today was to address some of the most frequent questions we get on our program and on levosimendan, and you guys have really illuminated some of the key areas of inquiry. So thank you.

It's an exciting time for Tenax to be at the forefront of an evolving field where there is so much unmet need. And we talked a lot about different strategies today. The trials over time will inform us if there is a single new solution, if there are two solutions, maybe complementary solutions. So -- we're looking forward to the time and the trials answering these questions. So thank you again to everyone, and we look forward to speaking to you in the future.

The conference has now concluded. Thank you for attending today's presentation. You may now disconnect.