All right. I think we're ready to get started here. Thanks so much for joining us again for our second annual Guggenheim Healthcare Innovation Conference and on day two. Next up in this room, I'm Bob Mulvaney, one of the bio pharma analysts here at Daniel Crozier from the Guggenheim team, up on the stage with me as well. Next in this room, we have the Gossamer team. We have Brian Geraghty, the COO and CFO, and Bob Smith, the CEO. Thank you both so much for joining, and especially with some of the travel issues we were just talking about. Appreciate you guys sticking with it and making it to Boston to join us.
Thank you for having us. Despite the travel, we would not miss your conference at all, Bob.
Yeah, yeah. Thanks so much. Maybe just to kick things off here, we were just saying how it's an exciting time getting close to a key data readout for Gossamer, but just for people maybe less familiar with the story, just an overview on the company, the history, and kind of how we got to where we are now. Then we'll talk about the.
Yeah, absolutely. Gossamer was founded in 2018, personally by our Chairman and CEO, Faheem Hasnain, coming off of a successful company build and exit from Receptos that was acquired by Celgene, which is now part of Bristol Myers Squibb, as folks may remember. We started life with a series of assets. In what I call the drug development deli slicer, we had a successful phase two with seralutinib, which was really one of the two foundational assets that we started the company around in early 2018. Seralutinib was invented by now employee of Gossamer, Dr. Laurence Zisman, when he was an academic cardiologist at the University of Albany, which was building upon the idea that the use of TKIs, or tyrosine kinase inhibitors, for the treatment of PAH could be very profound.
Part of that was underwritten by the clinical success that Novartis had seen by using imatinib in a PAH population about 15, 16 years ago. The side effect profile did not allow that drug to go forward. Larry, through a variety of mechanisms, invented seralutinib, which is a new chemical entity, much more potent and selective than what imatinib was, as well as designed to be an inhaled therapy, which we believe allows us to have a very benign side effect profile when it comes to some of the things that we're seeing with imatinib, which we think will give us long-term significant differentiation in the PAH and PH-ILD landscape.
Where we are today, to your point, Bob, we expect to have top-line results from the Prosera study, which is a multinational phase three registrational study in 31 countries, 191 sites, that we expect that top-line data to be in February of next year. We're anticipating last patient, last visit here by the end of this month, and spend time cleaning data and hopefully being in a position, as we said, to disclose that in February of this year. Our expectation, through a variety of ways and means of getting the right patient population, which was something we weren't able to do with our phase two Tori study because we were executing that during the COVID-19 pandemic, our hope is that we will have positive phase three data in February. We're guiding the investment community to a roughly 20-25 meter increase in six-minute walk distance.
On that success, that will begin a regulatory process in the U.S., as well as outside the U.S. with our partners, Chiesi, where we hope to have an approval and a launch in the, I would say, late second quarter of 2027, which we think, and certainly Bob can speak to, we think will be a fantastic setup for seralutinib to launch into a marketplace that will allow us to, we think, have significant market leadership.
Okay, great. Building on some of those comments, you mentioned your phase two Tori data. You shared some baseline characteristics from the Prosera trial earlier this year. Just give us kind of what we saw and what you see in those background characteristics and how it gives you confidence for Prosera.
We have to take a step back. Again, as I had said, Tori was executed during the height of the pandemic. It was the least sick patient population ever studied in a phase two clinical study in pulmonary hypertension. We put in a number of entry criteria for the Prosera study to make sure that we got a patient demographic that performed the best in the Tori study. You'll recall, in the Tori study, the primary endpoint was reduction in pulmonary vascular resistance. The secondary endpoint, although not powered, was six-minute walk distance. Those who had a REVEAL score of six or greater or were functional class three were not only statistically significant on PVR in the mid-20s, if you will, but those functional class three patients had an increase statistically significant of six-minute walk distance, about 37 meters.
We wanted to get a patient population that looked like that. In fact, we did. In our Prosera study, as opposed to Tori, which had roughly folks walking six-minute walk distance, about 408, 409, in Prosera, it is about 370, so meaningfully less. Our NT-proBNP, which, as you know, is a biomarker of right heart health, the Prosera studies were about, I think, 900 versus 600 in Tori. Importantly, the Tori study had about only one-third of the patients being functional class three. We are about 70% in the Prosera study. That patient population that performed the best, we have nearly three-quarters of the study with that patient population. Also very important is that Tori, because of COVID, was roughly 70%, almost 80% enrolled in the United States.
We only have about 17% of the patients coming from the U.S., which is really important because if you were to look at our friends at Merck in their stellar phase three study, the vast majority of those patients were coming from outside the United States as well. If you actually look at their data, the best performing region was Latin America. We have actually more patients coming from those same geographies and same sites. We do think that we have gone to the places where precedent studies have shown the greatest amount of efficacy, as well as having an entry criteria that is ensuring that we have patients who we believe will really show an improvement based upon, again, background disease at week 24.
Okay. You mentioned sotatercept and how that sort of comes in here and sort of impacts the market. Can you just remind us, how do you handle sotatercept use in the phase?
Yeah, it was actually quite interesting for us because once sotatercept was approved, we amended our protocol to enable people on background sotatercept to come into the Prosera study. Our expectations were that we'd have roughly about 10% or we enrolled 390 patients, so somewhere between 35-40 patients in Prosera would have been on background sotatercept. One of the entry criteria was you had to be on a stable dose of any background therapy for six months. We were quite surprised, actually, on how few patients we were able to enroll on background sotatercept. We only enrolled roughly nine patients. We had roughly 70 patients that were put into screening for the Prosera study. But Of those 70 patients, roughly 60 were not yet on a stable dose.
We saw not only meaningful dose reductions, but significant drug holidays because of the significant adverse event and liabilities that sotatercept had. While it was disappointing for us because we do have preclinical data that shows synergy with sotatercept, the liabilities of sotatercept precluded those patients from being able to come into the study. That being said, it did certainly give us some encouraging perspective into what the commercial reality will be when we are launched because, again, the burden that sotatercept has on providers and patients for monitoring the adverse events versus seralutinib, which, again, has some cough, has some headache, we think with our route of administration just lends itself to be an easier therapy for patients.
Ultimately, it's a good news, bad news thing in that we wanted more clinical experience, but the realities of the challenges of sotatercept were front and center for us.
Yeah. Okay. You mentioned, again, top-line data obviously coming in February, 20-25 meters six-minute walk distance, what you're hoping to see here. Can you just level set? What should we expect in the top-line release? What sort of data points will you be giving?
Certainly will be primary endpoint and hopefully, depending on just the flow of data, some of the key secondaries. We will have later in the year, probably more into the second quarter, I think, which will be a very critical piece of data, which will be our imaging data using the Fluidia CT technology that shows, as we showed in phase two. We only had 18 scans in phase two. Again, part of COVID, we have disclosed we expect to have over 120 in the Prosera study. That will come later, but on the heels of primary endpoint and key secondaries, the ability for us to show that revascularization of the lung. No other sponsor has done that. We think that, again, we like to say a picture's worth a thousand words.
If our team and Bob's sales team can be showing the clinical community that revascularization of the lung, that's going to be a competitive advantage that no other company in PAH.
Okay. All right. So let me turn it over to Daniel to kind of talk more about the commercial opportunity, assuming positive data.
Yeah, great. Thank you. Yeah, assuming a successful trial, how do you view the overall commercial positioning of this drug, both in the U.S., but also outside the U.S.?
Yeah. We have had numerous discussions with the experts in the community. As we have come along with the clinical community and we have seen the phase two open label data, we start laying out a target product profile for phase three. Plus, what we are seeing now with sotatercept with some of the serious adverse events that are being published in the FDA FAERS database, there is a little more hesitancy. It is still kind of the new kid on the block. There is nothing else. There are still a lot of patients that will benefit from it. Based on our efficacy profile, what we are seeing from a safety and tolerability standpoint, not only from phase two, but what we are seeing in blinded data in phase three is no new safety signals, no new tolerability signals.
With that, we expect for the majority of the patients to be started as that first third-line agent following standard of care of PDE5 and ERA.
Okay, great. Yeah. I know a lot of our discussions with investors, they bring up the idea of maybe some payer reluctancy around utilizing multiple high-priced therapies in combination. Maybe if you can kind of talk about discussions you've had with them and the path forward there, then they think it's possible.
Yeah. Generally, payers, I mean, this is a rare disease. Payers do not generally manage this area that closely. Most of the management comes around the use of a generic. For example, you have a generic ambrisentan versus still a branded macitentan. They are going to push for the generic in those situations. Again, it has not been managed. We are seeing with sotatercept very few issues from payers in getting reimbursement. Pretty wide open. There are always the exceptions out there, some small plan, but by and large, they are not seeing, we are not going to expect to see really many issues in our discussions that we have had with payers thus far. The other thing to keep in mind, speaking of generics, by the time we launch in 2027, you will have macitentan, Opsumit, selexipag, and Uptravi, which are the two largest therapies in the market, will both be generic.
Rather than that combination being a $400,000-plus patient, that'll drop 80-90%. At that point, you'll have Winrevair, you'll have seralutinib, and you'll have Tyvaso, and then maybe like a macitentan, 75, or the combination Opsumit product on the market. A lot of that money will be taken out of.
Yeah. I think, Daniel, where the reimbursement conversation is often ignored is what's going on outside the U.S. I think that's where the profile of seralutinib is quite advantageous. While Merck or MSD in Europe has been able to achieve relatively good pricing in some European countries, if you look at, for example, their current negotiations in the U.K. with NICE, and we're starting to hear this more in Europe, the pricing of the drug has to also take into account the cost of helping physicians deal with the AEs, right? You're going to get X price, but the overall cost burden for us is actually higher than just the drug price because we have to have a sidecar of money to be able to deal with the AEs that are coming. We certainly won't have that issue.
We believe we will have a similar construct as the ERAs when it comes to liver monitoring because TKIs do have a liver signal. The fact that in the U.K., they're pressing Merck for how much do we need to benchmark for hospitalization, how much do we need to benchmark for managing bleeds and the rest, that's not a conversation that our partners at Chiesi are going to have to have with European reimbursement agencies. Okay. Yeah, understood. Maybe you can just give like a broad overview of the steps you guys have already taken towards like the near-term plans on commercial readiness leading into this potential launch, the sales force size, and then kind of discuss it, but potential pricing of a drug like this.
Yeah. We are building out the commercial organization right now. We have a Head of Marketing, Head of Market Access, and a few other critical people that we need right now, kind of that timing being 18 months out to do a lot of the work, build the brand, build the brand plan, start preparing for the patient services, start preparing for the reimbursement. All of that is currently going on right now, right? We are going to gate some of that work to top-line readout, right? That is going on. The work with the payers has already started. From a sales force standpoint, when you have a single product that is kind of positioned third line after standard of care, you are looking at roughly 60 sales reps in the market. That is what Merck launched with, I think, 58 or 59. So kind of be 60, give or take.
I think we'll be able to penetrate out in the community a little bit more. Our target audience might be a little bit larger. We'll assess that. I think at launch, the focus will be on the major centers where you have these big bolus of patients that will have three years post-sotatercept. The whole prevalent population that would have tried sotatercept would have already tried it, right? You're going to have some on sotatercept, some refractory to sotatercept. That market will reset and we'll have no competition at the time, any new competition. We'll be able to gather all of those prevalent patients that are out in the market. You know, a pricing, we'll do most of that work next year.
You can probably expect if you look at the pricing of Tyvaso and you look at the pricing of Winrevair, that's probably decent analogs to think about. A lot will depend on what our phase three data ultimately looks like. That's a good guide that we're thinking through. We'll do a lot of that specific work in 2026.
Okay. All right. Maybe let me jump back in here. This is all great on PH-ILD. What we get in February, you've now started another phase 3 trial. Maybe we just talk about the decision to move into PH-ILD and what we should be kind of thinking about in terms of the patient population that you're enrolling this trial in and maybe broadly speaking the commercial landscape in PH-ILD versus PAH.
Yeah. So why don't I start there? The commercial landscape is dramatically different in PH-ILD than it is in PAH. Only one approved therapy in the US. I do think our friends at Liquidia will get a label if they haven't already. I know most of their sales were probably in PH-ILD. But inhaled prostacyclins are really the only prostacyclin-approved therapy in PH-ILD in the US, not yet approved in the European Union, approved in Japan. You have got one therapy versus now four approved pathways in PAH. You have got twice the patient population. The median survival time is about half in PH-ILD than what it is in PAH. It is about five years plus minus in PAH, it is about two, two and a half years in PH-ILD after the time of diagnosis. You have got effectively twice the number of patients, but with very, very, very little competition.
We think the economic opportunity, we think that seralutinib globally could be a $2 billion-$2.5 billion revenue opportunity in PAH. We think that PH-ILD could be a multiple of that. We have to look at the analog of inhaled Tyvaso before the entrance of Yutrepia, where they were doing about $400 million in PAH. Now I think they're on a $2.5 billion run rate because of PH-ILD. We activated our first site about a week and a half ago. We expect to enroll our first patient here before the end of the year. The patient demographic here is also, again, very different than in PAH. We're talking about a very, very sick patient population and a high unmet medical need.
About 60% of our Prosera sites, probably just plus minus 50% of our Prosera investigators will be in what we're calling the Seronata PH-ILD study. Part of the reason why we're so aggressive in setting up the study was keeping those sites very much engaged. There is obviously going to be competition with another phase three that our friends at Insmed will be up and running. Being able to go to places where we did not have to reinvent the wheel from an infrastructure perspective was very important. Our expectation, excuse me, it'll take probably 18-20 months to enroll the study. We expect it to be heavily enrolled in Europe because, again, the absence of approved therapies really has a very desperate patient population. We'll also go to geographies where the PH-ILD diagnostic infrastructure is very well characterized.
For example, in Japan, the relationship between pulmonologists and cardiologists is quite good. In Prosera, we had roughly seven sites in Japan. We could have north of 25 in Japan because they have really cracked the code well there. Mechanistically, we did also present some data at the European Respiratory Society that suggests that seralutinib also has real anti-fibrotic effect, which we think could also be very helpful in PH-ILD because you do have significantly more patients with lung fibrosis than you would in PAH.
Okay. Last couple of minutes here, a couple of other topics we want to touch on. You did an interesting transaction earlier bringing in another asset for PRN use.
Yes.
PH and PH-ILD. Maybe just talk about that opportunity and how it sort of fits in with the broader portfolio.
Yeah, absolutely. I think that, again, there's a company called Respira. They had an inhaled version of vardenafil known as Levitra, which is a very fast-acting PDE5. Not ideally suited for chronic use in PAH, but certainly ideally used for patients. We know that PAH patients have, especially as you're a sicker functional class two or functional class three patients, incidence of breathlessness, acute exercise incapacity. The idea of a PRN use of an inhaled therapy to give a patient a little bit of a boost or a reduction of breathlessness, it's really important to their quality of life. The transaction came about very simply. Respira was owned by one investor, Samsara Capital, which was our seventh largest investor.
They wanted to do an interesting deal based upon really our execution capability and what they thought, especially with the commercial organization that Bob's building, that we could make this a $500 million-$750 million product in the US alone. We're helping them with a CMC. It was an option deal. We're helping them with a CMC campaign. If that is successful, we will exercise the option to acquire the company. We issued 2,500,000 shares upfront. After the option exercise, it'll be 1,500,000 shares. A very capital-efficient way for us to expand the pipeline. Importantly, and I think this is the part that is not really appreciated, it was a very important sign to the PAH community that Gossamer is really going to be their long-term partner for the patients.
More importantly, coming with a novel delivery of a novel drug, not novel from an NC perspective, but the use being PRN. The enthusiasm from the clinical community has been overwhelming because yet again, here is Gossamer doing something very different to help their patients and distinguishing, I think, ourselves as a long-term partner for PAH patients. We do think this will have applicability in PH-ILD as well.
Okay. Maybe last minute, just cash position and sort of obviously the big readout in February, but just what's your cash runway get you?
We have cash until May of 2027. We have a convertible debt obligation that's due then, roughly $200 million. Giving guidance beyond that doesn't make a lot of sense, but plenty of capital to not only achieve the readout with Prosera, but to get the PHLD study well up and running.
Okay. All right. Great. Thanks again so much for joining us. Exciting times ahead. We will be watching closely. Good luck.
Thank you for having me.
Thank you.