United Therapeutics Corp

NASDAQ:UTHR

Earnings Call Transcript 2023-Q1

[Operator]

Good morning, and welcome to the United Therapeutics Corporation First Quarter 2023 Earnings Webcast. My name is Danielle, and I will be your conference operator today. [Operator Instructions] Please note this call is being recorded. I would now like to turn the webcast over to Dewey Steadman, Head of Investor Relations at United Therapeutics.

[Dewey Steadman, Head-Investor Relations]

Thank you, Danielle, and good morning. It's my pleasure to welcome you to the United Therapeutics Corporation First Quarter 2023 Earnings Webcast. Accompanying me on today's call are Dr. Martine Rothblatt, our Chairperson and Chief Executive Officer; Michael Benkowitz, our President and Chief Operating Officer; James Edgemond, our Chief Financial Officer and Treasurer; and then Pat Poisson, our Executive Vice President of Technical Operations; and finally, Dr. Leigh Peterson, our Senior Vice President of Product Development.

Remarks today will include forward-looking statements representing our expectations or beliefs regarding future events. These statements involve risks and uncertainties that may cause actual results to differ materially. Our latest SEC filings, including Forms 10-K and 10-Q contain additional information on these risks and uncertainties, and we assume no obligation to update these forward-looking statements.

Today's remarks also may discuss the progress and results of clinical trials or other developments with respect to our products. These remarks are intended solely to educate investors and are not intended to serve as the basis for medical decision-making or to suggest that any products are safe and effective for any unapproved or investigational uses. Full prescribing information for these products are available on the product's website.

Now I will turn the webcast over to Dr. Rothblatt for an overview of our first quarter 2023 financial results and the business activities of United Therapeutics. Martine?

[Martine Rothblatt, Chairperson and Chief Executive Officer]

Thank you, Dewey. Very excited to welcome everyone to another great quarter at United Therapeutics. We are thrilled to continue on course towards our mid-decade goals of 25,000 patients being treated for pulmonary hypertension and the doubling of our revenue run rate.

This quarter, we moved toward those goals with double-digit revenue growth from first quarter '22 to first quarter '23. And that also includes, by the way, nearly 40% growth in our main growth driver, which is Tyvaso.

I think our double-digit growth rate remains a solid forecast even with the possibility of new FDA approvals of sotatercept or Liquidia. The reason is that sotatercept has not even been tested in our main growth market of Group III pulmonary hypertension.

Indeed, systemic drugs are generally contraindicated there due to them causing VQ or ventilation perfusion mismatch. In the disease Tabarcept was tested in, Group I pulmonary arterial hypertension, we expect it to be complementary to either our Orenitram, Tyvaso or Remodulin products. So we don't forecast a realistic threat from sotatercept, to our growth.

Sales in Liquidia, if approved, also does not challenge our projected double-digit growth is because it is not a generic product, but is instead of a strongly differentiated drug device product requiring 65% more drug to even match Tyvaso's effect based on their own clinical trial data.

Also exciting to report this quarter is the robust progress in our pipeline. We are spot on target to fully enroll our current big Phase III trials by the end of next year, each of which have their own $1 billion potential. In other words, the pipeline now embeds more than double our current total revenues, and then there is the aforementioned organic doubling of our revenues from our existing products already commercialized and now entering the market, such as Tyvaso DPI, Remunity and our new Orenitram dose titration kits.

I'm also very excited to report big news on the use of capital front. We have allocated $0.5 billion to a new Tyvaso DPI manufacturing facility in Search Triangle Park, North Carolina, with 50,000 patient capacity. And by the way, this is in addition to our existing nearly $100 million allocation of capital to our new clinical Xeno transplantation facility in Virginia.

By the way, speaking about transplant, I'd like to thank the dozens of our shareholders and other stakeholders who sent me Amy Silversea's superb story of her heroism in the face of heart transplants and immunosuppressants. In that vein, I wanted to take a moment to update everyone on what we at United Therapeutics are doing to effectuate Amy's Quest.

In our own line of company, we reprogrammed differentiated cells from patients back to stem cells called IPSCs or inducible pluripotent stem cells. By the end of this year, we'll be creating IPSCs from two patient donors every single month. In our own labs, we differentiate cells into different types of cells need for cellularizing different organs, such as lung, including stromal cells and epithelial cells and different types of alveolar cells.

In our own labs, we grow differentiated cells in 3D changes into the billions of cells needed to cover each organ and in our own labs over the past three years we have produced about two trillion cells every year.

Also in our own labs, we cellularize our organ scaffolds with the cells that we have expanded. Indeed, last month, we achieved a kind of level of proof of concept for one of our own cellularized lungs, provided a pig model with the level of ox considered acceptable for human lung transplants.

Again, in our own labs, we produce this time under GMP conditions about 500 lung scaffolds every year and are now working on 3D printing kidney and liver scaffolds in partnership with 3D Systems. In short, Amy's vision of an immunosuppressant free organ transplant is realistic for this decade, the 2020s.

Here at United Therapeutics, we expect to have patient-derived stem cell differentiated autologous lungs, kidneys and livers in the clinic within five years. Parts could also be done, though immunosuppressants would be needed because the transplanted organs will have the same DNA as a patient.

So it is really the best of times here at United Therapeutics with record revenues, another $0.5 billion quarter; record pipeline potential, $2 billion-plus opportunities; and record deployment of capital and business expansion.

At UT, our mantra is go big or go home. We are going big on pulmonary hypertension. We are going big on pulmonary fibrosis. And we are going big on creating an unlimited supply of transplantable, tolerable organs. Michael Benkowitz, our President and Chief Operating Officer, will now give you a deeper dive into the business. Mike?

[Michael Benkowitz, President and Chief Operating Officer]

Thanks, Martin, and good morning, everyone. We're pleased to report yet another quarter of meaningful growth for our treprostinil business. And as Martine said, we're really excited to have quarterly revenues of more than $500 million for the second time in our company's history.

As usual, I'm going to provide some color around what we're seeing with respect to each of our treprostinil products, Tyvaso, Remodulin and Orenitram. For Tyvaso and Tyvaso DPI, underlying physician and patient demand for Tyvaso remained exceptionally strong in the first quarter as we continue to grow our Tyvaso active patients at a clip consistent with the patient growth trends for the prior three quarters.

We saw a record number of referrals, which is what we call prescriptions and new patient starts during the first quarter. We also continue to increase the breadth and depth of the Tyvaso prescriber base. Since the PH-ILD launch in 2021, we have now doubled the number of Tyvaso prescribers. That's our breadth metric. And in terms of prescribing depth, I've mentioned on prior calls that our key metric here is the number of prescribers with three or more Tyvaso patients.

I'm really happy to report that we've also doubled the number of prescribers in this category. The 3-plus Tyvaso prescribers now represent about 40% of all prescribers, which means we still have an opportunity to expand depth, which should pave the way to further accelerate Tyvaso growth over time.

The first quarter performance for Tyvaso saw the usual early year seasonality with respect to patient discontinuations due to insurance changes and also as usual, discontinuations returned to normal levels in February, March and in April. Importantly, discontinuations for Tyvaso DPI continue to run well below that of nebulized Tyvaso, reflecting patient satisfaction with Tyvaso DPI.

So overall, we believe the underlying strength of the Tyvaso business is great. Looking at first quarter revenue, as I said in the past, due to the nature of our business, we regularly encourage investors to look at longer-term revenue trends compared to quarterly revenue fluctuations. With that said, there were three main factors that impacted Tyvaso revenue in the first quarter, given that we're essentially in the middle of two product launches within the Tyvaso franchise, PH-ILD and then Tyvaso DPI.

First, and as we discussed last quarter, our specialty pharmacies are still rightsizing orders for the correct DPI and nebulized mix. In the third quarter of last year, specialty pharmacies made significant orders of nebulized Tyvaso in anticipation of increased PH-ILD demand without fully appreciating the potential for Tyvaso DPI demand.

Moving to the fourth quarter of last year and the first quarter of this year, we saw unexpectedly strong demand for Tyvaso DPI relative to nebulized Tyvaso. And the specialty pharmacies needed to reduce its nebulized inventory, which reduced Tyvaso revenue well under patient -- well under actual patient demand in the fourth quarter of 2022 and the first quarter of this year.

Second, we're seeing a higher level of PAP utilization for Tyvaso DPI than we expected. We believe this is a short-term phenomenon and will subside to a large degree when the Medicare changes that are part of the inflation reduction at go into effect starting next year.

Finally, due to the incredible demand for DPI and the fact that we launched immediately upon approval without building inventory, we have not been able to allow specialty pharmacies to up to their contractual minimum inventories each month. Based on our DPI demand trends and forecast, this is something that could persist for the balance of the year. Having said that, we are taking steps to increase DPI production capacity in both the short and medium term.

First, our partner, MannKind, is activating a second production line and additional kitting capacity from which we expect to see increased DPI supply as soon as this quarter. Second, and in parallel, MannKind is also on track to significantly expand manufacturing capacity in the first half of next year to support up to 25,000 Tyvaso DPI patients a year.

And finally, as Martine mentioned, we have initiated a construction project to build a new UT owned and operated Tyvaso DPI manufacturing facility. That facility is intended to provide enough capacity to support an additional 50,000 DPI patients per year and with expansion capacity for up to 75,000 DPI patients.

Turning to Remodulin. This business continues to be incredibly resilient, even though it's faced a generic competitor for almost four years now. We saw the second highest number of referrals for Remodulin in the first quarter. And after a small dip in active patients following the generic launch of a subcutaneous version of Remodulin, our active patients are back to pre-generic levels. Remunity continues to gain traction in the market as it is the only subcutaneous pump widely available for new Remodulin patient starts, with Remunity representing over half of our monthly subcu Remodulin shipments during the quarter.

Finally, Orenitram had a very solid quarter, achieving a record number of patients on therapy and record revenues. We launched a 90-day titration kit during the first quarter, which simplifies dosing and titration for new patients. While still early, physician and patient feedback has been very positive around the convenience of these new kits.

There continues to be a lot of buzz in the physician community around the expedite data we top-lined last October, demonstrating that prostacyclin induction with Remodulin can lead to double the average Orenitram dose when patients shift to oral therapy and in a shorter period of time as compared to patients who do not have a Remodulin induction. We expect to publish a peer-reviewed manuscript detailing the study in the coming months.

To wrap up, we're very pleased with the overall Treprostinil business, led by the incredible demand for Tyvaso DPI, and we believe we're on our way to hitting our goal of a $4 billion revenue run rate. With that, I'll turn the call back over to Martine to start the Q&A session.

[Martine Rothblatt, Chairperson and Chief Executive Officer]

Thank you so much, Mike. Those were terrific insights into every one of the products. We take that call that you shared with everyone.

Operator, could you please open the phones, and I will sort the questions to the person most appropriate for answering them.

[Operator]

[Operator Instructions] The first question comes from Joseph Thome of TD Cowen.

[Joseph Thome, TD Cowen and Company]

Mike, I know you mentioned that the Tyvaso DPI discontinuations are a little bit lower than what you were seeing with the nebulized Tyvaso. Maybe what are the expectations for the Tyvaso DPI average time on therapy versus what you were seeing with the nebulizer? And as we see sotatercept potentially launching maybe next year, do you expect the Tyvaso time on therapy could actually increase as these patients kind of continue to do maybe better than they did without sotatercept? Or would they intend maybe ramp down their use? How do you expect that to kind of play out?

[Martine Rothblatt, Chairperson and Chief Executive Officer]

Looks like direct this question to you.

[Michael Benkowitz, President and Chief Operating Officer]

Sure. So I think overall, we're really encouraged by the lower level of discontinuation rates with Tyvaso DPI. And we do think that, that augurs well for increased time on therapy. To put a number on that, I think it's still a little early to kind of say definitively what that's going to be. But certainly, a patient satisfaction has been really high with Tyvaso DPI.

I think it's led to better adherence, better compliance and that leads to patients doing better, and then that will ultimately lead to patients staying on therapy longer. So I think your premise, your hypothesis that time on therapy will increase with DPI over time is absolutely right. And that's something we're certainly expecting.

Similarly, I think sotatercept probably helps in that regard as well. If you look at the underlying data and the sotatercept study, 70% of the patients in that study were on a background prostacyclin. So as Martine said in her opening comments, we think there's a lot of complementary effects between prostacyclin and sotatercept.

And so we would expect that when sotatercept is launched into the market, that will continue and patients will experience a nice benefit between the two products as well as the other products on background therapy and should continue to lead to increased time on therapy.

[Martine Rothblatt, Chairperson and Chief Executive Officer]

Thanks, Mike. Operator, next question please.

[Operator]

Next question comes from Hartaj Singh of Oppenheimer.

[Hartaj Singh, Oppenheimer & Co.]

Nice update everybody. Just had a question on OrCam in the EXPEDITE study. I know at ERS last year in Barcelona really big updates there and educating the patient/physician community. It seems like at ATS this year, again, you will kind of delve into that. If you can just talk to us a little bit about what the patient flow is. Are patients mostly starting in Remodulin, and then going over to Orenitram? Or are they still starting Orenitram and what's the breakdown?

And then how can we expect sort of that to benefit Orenitram going forward? I know it already is, but could that add even more going forward?

[Martine Rothblatt, Chairperson and Chief Executive Officer]

Great question, Hartaj. Mike, I think you'd be, again, be the best person to address that question.

[Michael Benkowitz, President and Chief Operating Officer]

Sure. Thanks, Hartaj, for the question. So in terms of kind of the mix of patients between starting de novo and Orenitram transition from Remodulin, I think it's roughly, call it, 65 -- two-thirds roughly, two-thirds of patients are starting Orenitram right now.

And as I mentioned in my comments, I think the fact that we've got that titration -- new titration kit, I think that's going to continue to help patients titrate up on Orenitram starting de novo, and then the balance are transitions from Remodulin.

I still believe that there will be there will be patients that will start de novo or Orenitram over time once we really fully, I think, take advantage of the EXPEDITE data. But I also think it's true that Tyvaso DPI is proving to be so convenient for patients, and it's almost sort of your gateway drug to prostacyclin. So I think over time, you're going to see a higher number -- higher percentage of patients initiate prostacyclin therapy on DPI even over the orals, both Orenitram and selexipag.

And so the thing that we really like about the EXPEDITE data and then the ARTISAN study, which we've talked about on prior calls is it's an opportunity to take these maybe functional Class III patients or even IV patients in the case of Artisan, start them on Remodulin, get their hemodynamic hemodynamics down to closer to normal levels. And then you can flip them over to Orenitram and really use Orenitram as their maintenance drug, and continue to titrate up as you need.

And if they continue -- over time, they decline, you can obviously switch them back to Remodulin. But we really see that as sort of a key position for Orenitram as we move forward over the next several years. And in some, it really just kind of speaks to the flexibility of treprostinil and the fact that we've got these different delivery options. And so it really just, I think, allows us to kind of meet the patient and the physician where the patient is in their disease progression.

[Martine Rothblatt, Chairperson and Chief Executive Officer]

Great. Thanks so much, Mike. That was really beautiful the way you're able to describe that with ARTISAN and EXPEDITE and the whole rapid transition to oral. We're able to get patients into a stable equilibria, if you will, with the pulmonary artery pressures down around, I would say, below 40 millimeters of mercury. And there's like an increasing volume of data out there.

Well over a dozen scientific paper that have shown that patients with pulmonary hypertension who are managed in this kind of potential well between 30 and 40 millimeters of mercury are able to achieve very long-term survival, 10, 20 years out to the limit of the papers -- of the data that the papers had access to. And those are papers by independent physicians, not from us.

So we really believe that our initial mission of the company of being able to keep patients with pulmonary hypertension living with pulmonary hypertension instead of dying from pulmonary hypertension has been very largely achieved with the combination of parenteral prostacyclin to rapidly get their pressures down and then oral prostacyclin, Orenitram to be able to keep them stable in the long term. Operator, next question.

[Operator]

The next question comes from Jessica Fye of JPMorgan.

[Jessica Fye, JPMorgan]

On the plans to increase capacity for Tyvaso DPI, that sounds pretty bullish with respect to the anticipated demand trends there. And it sounds like you're seeing nice net patient adds as well. But can you just confirm whether there's any capacity constraint on DPI right now that's at all limiting to patient adds? Or is it that you're keeping up with patient demand and then in the near term, the capacity is maybe just keeping the specialty pharmacies from reaching target inventory levels?

And just related to that, I think you said Tyvaso net patient adds were in line with the past three quarters. Can you just remind me what that run rate was that you're tracking in-line with.

[Martine Rothblatt, Chairperson and Chief Executive Officer]

Okay. Thanks so much for the questions, Jess, and good to hear your voice this morning. There were several questions there. So let me start with the production expansion questions. And then, Mike, if you could queue up your responses to the rest of the questions that Jess asked there.

So Jess, we are pretty bullish on our forecast for Tyvaso DPI and the maximum capacity of the MannKind facility up in Danbury, Connecticut, will be by the beginning of next year, will be for 25,000 DPI patients. So we'll be entering '24 with a capacity for 25,000 patients.

Now as I mentioned in my introductory remarks, our company's goals for the middle of the decade are 25 -- being able to treat 25,000 pulmonary hypertension patients. So if a large proportion of those 25,000 patients are on Tyvaso DPI, which is, I think, reasonable, then it would be like, well, where is the production capacity for the go big on pulmonary fibrosis, whereas the production capacity for what we think the pulmonary fibrosis market will be.

Well, best as we can tell, we expect the pulmonary fibrosis market to actually be for Tyvaso DPI even larger than the pulmonary hypertension market. So we would need more than an additional 25,000 patient capacity for the pulmonary fibrosis market and indeed, the market research and the disease-modifying hypotheses that we have for Tyvaso DPI in pulmonary fibrosis is such that we could easily expect to have 50,000 pulmonary fibrosis patients being treated in addition to the 25,000 mid-decade pulmonary hypertension patients. So that's the reason why we need to start now deploying a substantial amount of capital to build this brand-new Tyvaso DPI production facility in Research Clinical Park, North Carolina.

As Mike mentioned, even that facility, even though its launch capacity will be 50,000 patients, it will have a surge capacity to go up to 75,000 patients. So we think between the 25,000 at MannKind, the 50,000 in North Carolina, the surge to 75,000 in North Carolina, as we enter the 2026 time frame, we then have a capacity to support 75,000 to 100,000 DPI patients which would cover our needs for both Group I pulmonary hypertension, Group III pulmonary hypertension, idiopathic pulmonary fibrosis and additional forms of pulmonary fibrosis that go under the rubric of proliferative -- progressive pulmonary fibrosis, which in fact, we are embarking on the other additional Phase III trial for. So Mike, with those comments in terms of the production capacity, can you answer the other questions that Jess had?

[Michael Benkowitz, President and Chief Operating Officer]

Absolutely. So Jess, I think your question around your first -- first part of your question was around sort of patient demand versus SP demand to build up their inventory. So it's -- we're definitely in the category of the latter. So we're not having to delay patient starts on DPI. We're making enough to meet the patient demand.

I think the issue that I was referencing in my opening comments is typically, specialty pharmacy, they have an algorithm for figuring out how much -- how they order every month. They typically try to order up to have, call it, roughly two months of inventory on hand and then over the course of the month, they'll get down to about 30 days. So they generally like to keep at least -- always be in a position where they have at a minimum 30 days of inventory on hand.

So due to the demand, we're not able to kind of meet that need on the part of the specialty pharmacy. Like I said, we have some additional production capacity coming online as soon as this quarter. That will start to open things up a little bit. But I think really between -- as we're continuing to grow over the balance of the year, we're probably going to be in this situation where they're not going to be able to order up to the levels they're accustomed to ordering up to until, as Martine said, we get that the significant expansion next year to get up to 25,000 patients.

Second part of your question was just sort of the average, I guess, the run rate in terms of patient adds. So if you look back over the last -- this quarter and the prior three quarters, it's kind of averaged up to around 500 patient adds per quarter on Tyvaso, and that's between both DPI and nebulized.

[Martine Rothblatt, Chairperson and Chief Executive Officer]

Perfect, Mike. Thanks so much. Operator, we're ready for your next question. .

[Operator]

The next question comes from Eun Yang from Jefferies.

[Eun Yang, Jefferies]

I have a question on TETON trial. So we are expecting data in 2025. So based on the Phase III increase trial, a subgroup of patients with underlying IPF, we saw benefits on FVC up to 16 weeks. So TETON trial is a 52-week time point. So do you expect benefits on FVC to continue to increase to 52 weeks? And then can you comment on powering assumptions for the TETON trial.

[Martine Rothblatt, Chairperson and Chief Executive Officer]

Thanks. Good morning, Eun. Nice to hear your questions. I think it will be best to have Dr. Peterson. She is in charge of running TETON trial answer your questions.

[Leigh Peterson, Senior Vice President of Product Development]

Yes. Thank you for your question. Yes, so in fact, the INCREASE study, indeed, the main study, the placebo-controlled study, was 16 weeks, as you mentioned. However, we do have an open-label extension study of the increased data where we've looked to see how the patients do over the longer period of time, including the 52-week time period.

And we still see benefits of patients on Tyvaso in the increased population. So we feel confident that, that will translate to the longer period in the TETON studies. And as far as the TETON studies, they are definitely powered, I mean, we have 90% power to detect the difference that we've seen in the increased studies with regard to absolute FVC. So we have sufficient power to see the difference over the 52-week period. So again, we feel confident on that.

[Martine Rothblatt, Chairperson and Chief Executive Officer]

It's very awesome. Thank you so much, Leigh. Operator, we are ready for your next question.

[Operator]

The next question comes from Andreas Argyrides of Wedbush Securities.

[Andreas Argyrides, Wedbush Securities]

Congrats on the quarter. When thinking -- so quickly, first, what's the status of the organ manufacturing programs? And when can we expect first clinical trial? And then how should we think about spend when it comes to organ manufacturing? And I have one follow-up.

[Martine Rothblatt, Chairperson and Chief Executive Officer]

Okay. We won't be able to take your follow-up, and Andreas congrats on the quarter. Your line broke up a little bit, but I think the gist of the question was to get an overview of the organ manufacturing situation and when we expect results of the organ manufacturing to enter into clinical trials.

And I think you asked something about the capital associated with other spending. So the organ manufacturing program is a broad, multifaceted, multiple shots on Gold programs. So it won't be really realistic to give an overview of everything beyond the really exciting things I mentioned this morning that in response to any silver teams passionate arguments that part of our organ manufacturing program is strongly focused on organs that would not require immunosuppressants.

In other words, autologous organs that are manufactured with the cells downstream from a patient's own donated cells. And we -- within different laboratories at United Therapeutics, we currently produce iPSC cells. In other words, we reprogram PBMCs and another differentiated cells from patients back into stem cells. We then used techniques proprietary to the company to then differentiate those stem cells into the different types of cells that we would cellularize organs with.

Other programs at other laboratories within United Therapeutics are based on allogeneic cell lines that we are able to MHC segment. So patients could expect a much lighter immunosuppressant load than if they were just taking kind of an average donor organ.

And then let me get to your question about the clinical trial. So the organs we have closest to clinical trials are our Xeno hearts and Xeno kidneys. These are hearts and kidneys from donor animals that have been grown under the equivalent of good manufacturing practices conditions, whether called pathogen-free conditions.

And they have 10 genetic modifications that we believe will allow them to surmount hyperacute and acute rejection with no more than the normal commercially available immunosuppressants today, and be able to continue on to a long-term duration in the recipients body with the management of chronic rejection as is done today with allografts.

So those organs are currently in what's called by the FDA a pivotal preclinical program. That means it's the last preclinical program before going into a human study. And that program is -- hopefully, we will be able to complete that program by the end of '24 and be able to then enter into the first clinical trials in '25.

So that would be kind of a bottom line answer to your question at the first manufactured kidneys and hearts hopefully. Knock on wood, should be able to enter into clinical trials in '25. Operator, we've got time for one last question.

[Operator]

The next question comes from Ash Verma of UBS.

[Ashwani Verma, UBS]

I had one on sotatercept impact. So the feedback that we've heard for physicians indicates that Merck's product positioning and payer reception can have an important bearing on what part of your portfolio may get impacted. In your view, does that matter? And like what is the assumptions that you have on competitors' pricing in line of therapy positioning?

[Martine Rothblatt, Chairperson and Chief Executive Officer]

Okay. Thanks for the questions, Ash. Like a frontline question that Mike an answer, and Mike will give you more of a definitive answer. But as I noted in our introductory remarks, we don't see sotatercept having any effect whatsoever on the growth guidance that we've provided for our company.

And the reason for that is a lot of people are not completely clear that there are two different diseases that are treated with drugs such as ours that sound very similar and it's easy to get them confused. So the disease that sotatercept was tested in and the disease that all of our drugs are approved for all of our non-cancer drugs are approved for is called Group I pulmonary arterial hypertension, and the acronym is PAH.

A different disease is called Group III pulmonary hypertension or just Group II PH. Sotatercept has never been tested, at least anything published that we're aware of, in Group III pulmonary hypertension. The only drug approved for Group III pulmonary hypertension is Tyvaso, including Tyvaso DPI.

And as Mike described very well, most of our growth in the coming years, we expect to come from Group III pulmonary hypertension. So by definition, sotatercept cannot have any effect on that growth trajectory whatsoever.

In addition to that, within the group I pulmonary arterial hypertension, where we do continue to have growth across our franchise, I think Mike mentioned we had our highest quarterly sales of Orenitram ever, we expect sotatercept to be complementary.

And Mike, would you like to expand on that?

[Michael Benkowitz, President and Chief Operating Officer]

Sure. I'll just kind of pick up right there, which is, I think I said in response to an earlier question around this, we definitely look at sotatercept as complementary to our drug and the other drugs that are currently on the market to treat Group I PAH. It's another pathway to now we have a drug to treat four different pathways, associated with pulmonary arterial hypertension. If you look at the -- as I said, if you look at the data in the sotatercept trial, 70, 7-0, 70% of those patients were on prostacyclin therapy.

So clearly, there appears to be a complementary or synergistic effects between prostacyclin and sotatercept. So we think that all of the drugs will continue to be used. I think some physicians that we've talked to have talked about, this sort of Four Corners approach of treating PAH, so you have a drug to treat each of the four pathways. How that gets sequenced and -- in the grand scheme of things doesn't really matter because I think it's still a progressive disease. There was nothing in the sotatercept data really to suggest that it's a cure or even a disease-modifying agent.

I know there was some speculation that, that might be the case, but I don't think that's borne out in the data. So clearly, patients are benefiting from it, but I think it's a combination with the other drugs. And so we think over time, it's another drug that physicians can add to their treatment on rematarium, but it doesn't appear to be something that's going to replace or displace our products.

[Martine Rothblatt, Chairperson and Chief Executive Officer]

Thanks so much, Mike. And thank you, operator, and everybody, for joining our first quarter conference call. The great work of Dewey Steadman. We'll be presenting at various and sundry health care conferences during the balance of the year, and we look forward to seeing you there and providing additional insights and color on United Therapeutics business. Operator, you can disconnect the call.

[Operator]

Thank you for participating in today's United Therapeutics Corporation earnings webcast. A rebroadcast of this webcast will be available for replay for one week by visiting the Events and Presentations section of the United Therapeutics Investor Relations website @ir.unither.com