Aurinia Pharmaceuticals Inc

NASDAQ:AUPH

Earnings Call Transcript 2024-Q1

[Operator]

Greetings, and welcome to the Aurinia Pharmaceuticals First Quarter 2024 Earnings Call. [Operator Instructions] As a reminder, this conference is being recorded. It's now my pleasure to turn the conference over to Andrea Christopher, Head of Corporate Communications and Investor Relations for Aurinia Pharmaceuticals. Please go ahead, Andrea.

[Andrea Christopher, executive]

Thank you, operator, and thank you to everyone for joining today's call and webcast. Joining me on the call this morning are Peter Greenleaf, Aurinia's Chief Executive Officer; Joe Miller, our Chief Financial Officer; and Dr. Greg Keenan, our Chief Medical Officer.

Today, we will review and discuss Aurinia's 2024 first quarter financial and operational results as communicated in the company's press release issued this morning. The company also filed its quarterly financial statements on Form 10-Q this morning. For more information, please refer to Aurinia's filings with the U.S. Securities and Exchange Commission and applicable Canadian Securities authorities, which are also available on Aurinia's website at auriniapharma.com.

During today's call, Aurinia may make forward-looking statements based on current expectations. These forward-looking statements are subject to a number of significant risks and uncertainties and actual results may differ materially.

For a discussion of factors that could affect Aurinia's future financial results and business, please refer to the disclosures in Aurinia's press release, its quarterly report on Form 10-Q and its annual report on Form 10-K and all of its recent filings with the U.S. Securities and Exchange Commission and Canadian securities authorities.

Please note that all statements made during today's call are current as of today, Thursday, May 2, 2024, unless otherwise noted and are based upon information currently available to us. Except as required by law, Aurinia assumes no obligation to update any such statements. Now let me turn the call over to Aurinia's President and CEO, Peter Greenleaf. Peter?

[Peter Greenleaf, executive]

Thanks, Andrew, and good morning, everyone. I want to thank everybody for joining us on today's call. On this morning's call, we will focus on the company's first quarter performance. I'll then turn the call over to Joe Miller, our CFO, to provide additional details on our financial results. We saw continued strong momentum in the first quarter, reflecting the initiatives that the company is focused on, including demonstrating solid commercial execution, rapidly restructuring the company and reducing our headcount by approximately 25% and accelerating the company's time line towards cash flow positivity.

So now let me dive into the first quarter business performance and how we're executing on these overall initiatives. For the first quarter of 2024, Aurinia achieved $50.3 million in total net revenue, representing growth of approximately 46% year-over-year.

We achieved $48.1 million in net product revenue, representing significant growth of approximately 40%. With this momentum, we remain on track to achieve our net product revenue guidance range of approximately USD 200 million to USD 220 million. In terms of our restructuring efforts, we executed with speed and precision following the announcement on February 15, while maintaining our focus on LUPKYNIS and growth.

While we've ceased development on AUR300, we are currently exploring alternative approaches for AUR200. Taken as a whole, we expect the restructuring will drive the organization to a cash flow positive position excluding share repurchases and over time, will provide meaningful accumulation of cash, increasing tangible value and allowing more flexibility for the company for the future.

As part of our corporate restructuring, we reduced employee headcount by approximately 25% in the first quarter. With this effort, we expect to reduce operating expenses by $50 million to $55 million over the next 12 months and approximately 75% of that will be recognized in this year. The company expects total annualized operating expenses on a go-forward basis to be in the range of $185 million to $195 million, with cash-based operating expenses of approximately $155 million to $165 million.

With these achievements in mind, I'm very pleased to confirm that we expect to be cash flow positive, excluding share repurchases in the second quarter of 2024 ahead of our prior projections. On the commercial front, we are laser-focused on driving LUPKYNIS revenues and have several key commercial metrics driving the brand's trajectory.

In the first quarter, we added 448 patient start forms and approximately 148 new patients who were either restarting LUPKYNIS or receiving it through the hospital pharmacy. Together, these total approximately 596 PSFs in combination with restarts and hospital fills versus 466 PSFs in the prior year first quarter, representing substantial year-over-year growth.

There were approximately 2,178 patients on LUPKYNIS therapy as of March 31, 2024, in comparison to approximately 1,731 patients as of March 31, 2023, an increase of approximately 26%. And this was driven by overall improvements in all key commercial metrics. Net realizable revenue per patient for LUPKYNIS remains higher than our initial guidance of $65,000 per patient on an annualized basis.

As persistency adherence and pricing has evolved over time, we now believe that net realizable revenue per patient will be in the range of $70,000 to $75,000 on an annualized basis. From the start of the year through April 28, 2024, the company has added approximately 582 PSFs and approximately 170 new patients from restarts in the hospital channel.

We continue to sustain high conversion rates with approximately 85% of PSFs converting to patients on therapy. We also sustained a rapid conversion time with approximately 60% of patients starting therapy within 20 days. Our overall adherence rates remained high at 87% through the first quarter and persistency grew year-over-year from approximately 51% of patients remaining on therapy at 12 months to approximately 56% remaining on therapy at 12 months.

Additionally, in the first quarter, 50% and 46% of patients remained on therapy at 15 and 18 months, respectively. Based on all of the above, we are reiterating our full year guidance. Our metrics demonstrate continued growth that is driving the upward trajectory of LUPKYNIS. We are heading towards cash flow positivity and increasing the company's financial strength and flexibility for the future.

Along with this strong financial performance, we also recently achieved several key milestones, reflecting the importance of LUPKYNIS as a best-in-class drug with a strong clinical portfolio that aligns with the most current treatment guidelines. As announced earlier this week, the FDA has approved a label update for LUPKYNIS.

The label no longer includes language indicating that the safety and efficacy of LUPKYNIS has not been established beyond 1 year. The label now includes long-term data from a post-hoc analysis of the AURORA 2 extension study. The data showed that patients receiving LUPKYNIS achieved sustained complete renal response at every time point assessed throughout the 3 years when compared to MMF and low-dose glucocorticosteroids alone.

Shifting to our marketing efforts, we recently launched the Know the Signs campaign and innovated a new campaign designed to increase awareness among rheumatologists about the severity of lupus nephritis and the urgent need to prioritize kidney health for people with lupus as well as encouraging them to increase screening for lupus nephritis among lupus patients.

With an underdiagnosed and underserved population, we continue to believe there is still significant untapped potential in the LN market. Current screening and treatment guidelines are not actually being followed. We know that a high percentage of lupus and lupus nephritis patients are not being given regular urine screens at every visit and may still only receive steroids when proteinuria levels indicate additional treatment is necessary.

Yet, our clinical trials have shown that lupkinis reduced proteinuria roughly 3x faster than MMF and steroids alone. This is why we're heavily focused on improving physicians understanding of the seriousness of lupus nephritis. We want rheumatologists to understand the necessity of more aggressively treating and diagnosing LN patients by treating to target protein levels and keeping them on therapy for a minimum of 3 to 5 years, all of which closely aligns with current treatment guidelines.

Regarding commercial activities outside the U.S., we're seeing continued revenue from Otsuka's launch activities in Europe, and we're also working diligently to expand access to LUPKYNIS to another key market with our pending regulatory approval in Japan. As previously noted, we expect to receive a response from the Japanese regulatory authorities in the second half of this year regarding the JNDA that Otsuka filed in November of 2023 for the approval of LUPKYNIS to treat adults with active lupus nephritis.

Upon approval, we expect to receive a milestone of $10 million and from their low double-digit royalties on net sales once launched. So in summary, we believe our first quarter accomplishments reflect solid execution against our previously announced business priorities.

I also want to recognize that May is lupus awareness month. At Aurinia, we take great pride in the work we do every day to improve the lives of people living with lupus nephritis. We are committed to making a difference for this patient community, and we never lose sight of that.

I'd now like to turn the call over to Joe for a more detailed review of the financial results, but I'll return at the end of the call for a quick recap and then open the line to any questions that you might have. Joe?

[Joseph Miller, executive]

Thank you, Peter, and good morning, everyone. Let's take a few minutes and go into detail regarding our financial results for the first quarter of 2024. Total net revenue was $50.3 million and $34.4 million for the 3 months ended March 31, 2024, and March 31, 2023, respectively.

Net product revenue over the same period was $48.1 million and $34.3 million, representing growth of approximately 46% and 40%, respectively. The increase is primarily due to an increase in LUPKYNIS sales from our 2 main specialty pharmacies, driven predominantly by further penetration of the LN market.

Total cost of sales and operating expenses inclusive of onetime restructuring charge in Q1 2024 were $63.6 million for the quarter ended March 31, 2024, and $64 million for the quarter ended March 31, 2023. It is important to note that the first quarter was fairly burdened from an operating expense standpoint as the restructuring charge was not fully implemented until late in the first quarter of 2024.

Let me now give you a further breakdown of operating expenses, drivers and fluctuations. Cost of sales was $7.8 million for the quarter ended March 31, 2024, and $421,000 for the quarter ended March 31, 2023. The increase is primarily due to increased sales of LUPKYNIS, coupled with the amortization of the mono plant finance right-of-use asset, which was placed into service in late June 2023.

Gross margins for the quarter ended March 31, 2024, and March 31, 2023, was approximately 85% and 99%. Selling, general and administrative expenses, inclusive of share-based compensation were $47.7 million and $50.1 million for the 3 months ended March 31, 2024, and March 31, 2023, respectively.

The primary drivers for the decrease were lower corporate costs, employee-related costs due to the reduction in headcount, which occurred late in the first quarter of 2024 and lower spend for travel. The decrease in SG&A operating expenses reflects the early impact of our restructuring efforts though this balance does not include the onetime restructuring charge.

The onetime restructuring charge is reflected as a stand-alone line item in the profit and loss statement and will be discussed separately in a moment. Noncash SG&A share-based compensation expense was $7.5 million for the first quarter of 2024 and $7.6 million for the prior year period.

Research and development expenses, inclusive of share-based compensation expense was $5.6 million for the quarter ended March 31, 2024, and $13.2 million for the quarter ended March 31, 2023. The decrease is primarily related to exiting our pipeline programs as previously announced, but does not include the impact of the onetime restructuring charge, as previously mentioned, the onetime restructuring charge is reflected as a stand-alone line item.

Noncash share-based compensation expense included within R&D expense was a credit of $2.2 million and an expense of $1.6 million for the quarters ended March 31, 2024, and March 31, 2023. The primary driver for the decrease in share-based compensation is related to the reduction in headcount, which occurred late in the first quarter of 2024.

Restructuring expenses for the quarter amounted to $6.7 million in the prior year period to 0. The balance is primarily made up of employee severance and onetime benefit payments and contract termination costs. The company has recognized most of its planned restructuring costs in the first quarter.

Other income was $4.1 million and interest expense was $1.3 million for the quarter ended March 31, 2024, compared to other expense of $290,000 and no interest expense for the prior year period. The changes for both other income and interest expense related to our mono plant finance right-of-use asset, which is denominated in Swiss francs and was placed into service in late June 2023.

Interest income was $4.5 million for the quarter ended March 31, 2024, and $3.8 million for the prior year period. The increase is due to higher yields on our investments as a result of increased interest rates. Aurinia recorded a net loss of $10.7 million or $0.07 net loss per common share for the quarter ended March 31, 2024, as compared to a net loss of $26.2 million or $0.18 net loss per common share for the quarter ended March 31, 2023.

As of March 31, 2024, Aurinia had cash, cash equivalents and restricted cash and investments of $320.1 million compared to $350.7 million at December 31, 2023. The decrease is primarily related to continued investment in commercialization activities and post-approval commitments of our approved drug, LUPKYNIS, mono plant payments, share repurchases and restructuring-related payments, partially offset by an increase in cash received from sales of LUPKYNIS.

The company remains debt free at March 31, 2024. With that, I would like to hand the call back over to Peter for some closing remarks. Peter?

[Peter Greenleaf, executive]

Thanks, Joe. Obviously, we're looking forward to continued strong performance in 2024 and beyond. I want to thank you all for your time today. We will now open up the lines for any questions you might have. Operator?

[Operator]

[Operator Instructions]

Our first question today is coming from Maurice Raycroft Recro from Jefferies.

[Farzin Haque, analyst]

This is Farzin on for Maury. I wanted to ask on the implications of the updated label. Your conversion rate for the PSF has been in the mid-80s. Do you expect that to further or do we expect primary to influence prescribers perception of the drug?

[Peter Greenleaf, executive]

So thank you for the question. Listen, I think the label update is a recognition of -- by the agency of data that we provided in addition to the original AURORA pivotal study. I think it's going to be helpful to not be concluded in the indication language that anything beyond 1 year has not been studied.

To have that taken out and to have the 3-year data incorporated in the label is going to help us, I think, on multiple fronts. Probably not on the conversion side of the equation, but we'll see. We're looking at it more on the -- probably the persistency side and ensuring that the drug gets utilized as both the ULR and KDIGO guidelines outlined 3 to 5 years of therapy approximately. So we see it more as persistency and length of therapy and additive to the already published data that's out there.

[Farzin Haque, analyst]

Okay. Makes sense. And then last month, you had like 156 that accounted, the total PSS and restarts. So this is trending a bit lower than the average 1Q monthly numbers. Is that the lumpiness or were there any factors driving the slowness in April?

[Peter Greenleaf, executive]

Well, the exact number, I think, in combination plus the restarts and hospitals was closer to 170. So probably just you were quick doing the math, I think it was 170. If you look at that on a per week basis versus where we were in the first 13 weeks of the year, it's pretty consistent, maybe slightly lower, but pretty consistent with what we did in the first quarter of the year.

If you look at April '23, it's almost directly on target with where we were in April of '23, but that was just a PSF number last year. So if you look at PSF's sort of on April '23 versus PSFs alone in April '24, the numbers were very consistent. The big driver of the change in about 25% improvement year-over-year in the month of April was driven by both restarts and hospital patients.

[Operator]

Next question today is coming from Stacy Ku from TD Cowen.

[Stacy Ku, analyst]

Sorry if I repeat a question because I got kicked off momentarily. We did have a few. First is a follow-up to what I believe was the first question. Just can you talk about big picture? What's your evolving thoughts around patient start forms and the current case additions as we look forward? And then how important is formulary purchases in the hospital channel for your long-term growth? That's the first kind of question. I have a few follow-ups.

[Peter Greenleaf, executive]

I think it's a great question. Obviously, PSFs we see as important. But I think as you've seen -- because I think it's the best indicator of new patient volume. And since 85% of those convert, new patient starts and kind of are equivalent of an NRx, right? But this emergence over the last, let's call it, 6 to 12 months of the importance of restarts and albeit smaller, but emerging hospital business show new lines of growth.

So the way we talk about it, Stacy, internally is more how does our new patient on therapy numbers look within the quarter. And I think that's an important one. And that's a combination of all the [indiscernible] I'm not trying in any way to discount the importance of PSFs.

We think all our marketing and selling initiatives that we have out there, primary driver is identifying new patients and getting new patients on drug. But for the last, let's call it, 6 months plus, a lot of our growth has come from both these restarts, which I think points to the importance of the AURORA 2 extension study, this label change and the work we've been doing over the last 12 months.

But it doesn't, in any way, in my mind, discount the need to focus on new patient growth. And while the hospital patients are indeed new patients, the PSFs are still a major indicator for that.

[Stacy Ku, analyst]

Okay. Understood. And then around your '24 revenue guidance, you want to just walk through, remind us about the seasonality, quarterly cadence expectations? And how you feel about kind of your revenue guidance for the high and low end this year?

[Peter Greenleaf, executive]

Well, as you know, we don't give any numeric or sort of pillars to the high and the low, but sort of qualitatively speaking, I think the low end of the guidance with the quarter we just produced would have to see a significant decline or some challenge in the summertime and then back to growth in the fourth quarter and the high end of the range, this is very generally how we think of it and getting above that range is going to be driven by how well we perform in the summer.

Since for 3 seasons now, we've had a little bit of a dip during the summertime or flattening in the summertime. If we can power through that, we think we have the ability to be in the upper end of that range. Lastly, I think 2Q performance will be a key driver to look at guidance in general and see where we are for the year.

And with that outperforms, then we'll come back to the table and talk about where we see the year coming out. But the biggest swing on that $200 million to $220 million range is going to be the summer months of the year.

[Stacy Ku, analyst]

Okay. Understood. And then last question is just a follow-up on your comments around exploring alternative approaches for your pipeline product, 200. But just help us understand what does that mean? Can you go into a little bit more detail for us?

[Peter Greenleaf, executive]

Yes. I think the short answer is the difference between AUR200 and 300 in our pipeline was own AUR200. Yes, we have follow-on commitments to those that we purchased it from very minimal, but we do have commitments. So we will either seek to develop the drug through someone else or to efficiently move the drug forward on our own if, in fact, conversations with others don't produce the type of value that we would see for the asset and the type of speed we would want for the asset.

So in other words, we don't want to just shelve it and not get the value of this April BAF inhibitor, which obviously more and more data emerges every day on the April bat space as it pertains to IgAN in particular. But we think more broadly, there's going to be a place for April BAF inhibitors in the B-cell pathway and much more immunology disorders moving forward. So we want to keep this thing moving forward, whether it's in our own hands or someone else's.

[Operator]

[Operator Instructions] Our next question is coming from Joseph Schwartz from Leerink Partners.

[Joseph Schwartz, analyst]

Congrats on a strong quarter. I wanted to ask first about your initiatives around screening and diagnosis. Where is the community now on that front? How much screening is being done? And how much have you been able to move that needle? And how is progress there contributing to new patient starts relative to the other initiatives you have ongoing?

[Peter Greenleaf, executive]

Thanks for the question, Joe. I think we have one series of sort of physician-reported AAU that's been done. And at least at the rheumatologist level, what we can tell you is that we're seeing some improvement in treatment. We're seeing some improvement in awareness of need to diagnose lupus patients and do urine screens. We haven't seen that, Joe, pull through yet to actual claims data.

And there's no direct. It's not one to one, and it's kind of even our interpretation of claims state is kind of you have to take some liberties around what's submitted through the claim to try to get under that. What I can tell you is these numbers have been like grossly low historically at least as reported by a large patient record audit that was done by Optum a few years back, looking at lupus patients, a couple of hundred thousand lupus patients over several years.

And you're looking at numbers like less than 50% of these patients even get a urine screen. This is lupus patients. guidelines say they should get it every time they come in the office. And when they do have a positive proteinuria or a proteinuria level that the guidelines would indicate indeed is a lupus nephritis diagnosis. Only 30% of them even get treated. And you say, well, geez, why?

I think one is just general awareness and I think hematologists will treat proteinuria and lupus nephritis differently. I think they see lupus nephritis as several grams of proteinuria and -- or protein in the urine, and they see low proteinuria as not indeed being nephritis.

Now it's a little bit of a liberty from some of the research work we've done, but the awareness we need to build is that even low levels are indicative of poor outcomes for the patient moving forward, and you're never going to find it unless you're doing the urine screens. So I think we're making impact there, more to come as we continue the campaign forward.

[Joseph Schwartz, analyst]

Yes, it seems like a great area for our white space. I was wondering also regarding the updated label, I think that happened a fair amount ahead of expectations, given we were expecting an update in the second half.

So can you talk about why that turned around so fast? How does the updated label fit within your expectations? And is there any potential to limit the REMS in the future with any additional label updates going forward?

[Peter Greenleaf, executive]

Well, we don't have a REMS in a technical sense. So maybe I'll answer the question and maybe as you're thinking about it, Joe, come back to me with what you mean by the REMS. As we previously communicated, we let the agency know that we were going to do the extension study and that we were also going to do a biopsy substudy as part of the pivotal.

The agency said great, we'd love to see that data, but it wasn't packaged as your classic supplemental NDA, right? So when we fed this data to the U.S. FDA. Obviously, we were glad they would take it, but understood that it wasn't -- it could potentially fall outside of the technical supplemental new drug application process.

The agency luckily treated it much like a supplemental. And they performed within the 9 to 12 months category of what a normal supplemental is. And we were more conservative probably in our estimate because this technically was, in our view, a supplemental NDA package. So it came earlier than maybe the way we guided externally, which is a positive.

And I think in terms of our expectations, this hit pretty much on everything we had expected. We wanted the language removed from the indication statement now that there's more than 1 year data, and we wanted the data incorporated. I will say that the biopsy substudy data was not incorporated, but we don't think that's limiting. We think that data can still be made available through publication and through medical drug and information request forms.

[Joseph Schwartz, analyst]

That makes sense. That answers my question. And then what about your recently announced buyback? Have you made any progress buying any shares back yet?

[Peter Greenleaf, executive]

Short answer is yes. While within the quarter, we actually up until -- I believe this is up until the end of April. We purchased about $18.4 million worth of stock with an average cost of $5.37, which equates to about 3.4 million total shares.

On -- just for future because I'm sure that's kind of the follow-on question. We would look to fund any future purchases through -- discretionary repurchases through cash flows and not through what's the cash on hand, and it's at the Board's discretion. So we'll report out more as we go here, but 18.4% through the end of April.

[Operator]

Your next question is coming from Ed Arce from H.C. Wainright.

[Antonio Arce, analyst]

Just a couple here. I wanted to follow up again really on the bigger picture here in particular, with the updated label. I gather you've got the main aspects of that you got into this new label. In particular, I wanted to have you speak a little bit further, Peter, if you could, on your view of that, the impact of that label, particularly longer-term persistent and doctors eventually treating this as a long-term treatment. along with the now the signs campaign, which in particular targets to rheumatologists, which have been the lower prescribing group of the 2. Just broad thoughts on the longer-term perspective and impacts of those.

[Peter Greenleaf, executive]

Well, I'm sure it wasn't missed on anybody, but over the last couple of quarters, we've actually seen improvement in terms of our persistency. And at least from my history of doing this for a little while and multiple drugs, persistency is a really hard thing to move.

In the biologics category when we launched anti-TNF, remember those numbers staying fairly consistent for a very long time no matter how much money we throw at it. And I think here, we were sort of right below 50%. We hedged up to 50% at 1 year. Now we're at 56%. So on a macro level, I think having this data out there that shows that at least this C&I can be used, this next-generation C&I can be used for longer periods of time is incredibly helpful.

I think alongside of that, the guidelines are now very vocal about aggressive diagnosis, earlier treatment. They've always been fairly consistent about levels and needing treatment, but now they're very clear. And you actually have companies and investment going into educating and making sure that people start to actually put these guidelines into play.

So for the longer term, the bigger picture question, we need to see more aggressive diagnosis in the rheumatologist office. We need to see target levels of proteinuria treated by rheumatologists when there are signs. And this is not just Aurinia's goal. This is the goal of the treatment guidelines. And then those treatment guidelines estimate the patient should be on an estimated 3 to 5 years.

So all of those things have significant level of improvement that can happen. And I think that's what's going to move this whole category to a much larger opportunity for the industry. And I also think it's going to take the burden of disease for the patients we're trying to care for here and take it down dramatically. So that's kind of the big picture view at least as we see it, Ed.

[Antonio Arce, analyst]

Great. That's helpful. A couple more, if I may. Just one question on AUR200. You mentioned that remains a very interesting target, the April BAF inhibitor. Just wondering if you have any particular development time lines or anything you can share in terms of news flow near term with that?

And then last question, I wanted to ask about the comment about the newer higher expectations for the kinase pricing, 70% to 75% versus the 65% previously. What is it that you think has persisted and changed your view from prior expectations?

[Peter Greenleaf, executive]

Yes, I'll take the first one, and then I'll let Joe kind of give his two cents on the 70% to 75% average net. Listen, I think just to give the most updated information that we have on AUR200, the IND was approved by the U.S. FDA. So we are ready to start SAD/MAD studies. And we'll as I said on the call, our goal is to keep this thing moving forward.

So when we actually do have a path, whether it's internally or externally forward, we understand that getting clear about how long those SAD MAD studies will take when you're going to have your first in-human clinical studies and when you should expect to see Phase II data, Phase III data, et cetera, and in what indications soon.

So I would earmark that one for a future call, but know that the IND has been approved by the U.S. FDA, and we're moving into animal tox and in SAD/MAD studies this year, either through Aurinia or through an external party. So the pricing question, let me kick that to Joe.

[Joseph Miller, executive]

Ed, yes, to follow up on your pricing question, it's kind of 2 factors. One is, obviously, Peter already touched on it, which was the persistency itself that has evolved kind of considerably over time. I think if you look back, Q1 of '23, it was about 51% at 12 months. It's now moved to 56% at 12 months. So that's probably our largest driver for the evolution of the net revenue per patient estimate. Also, couplement of that is some small price increases over time that have kind of inched up that number on average.

[Operator]

Our next question is coming from David Martin from Bloomberg.

[David Martin, analyst]

Yes. First off, also going back to the updated LUPKYNIS label. Is there any part of that could give rise to new patent claims do you think? Or is everything related to the change already in your existing patents?

[Peter Greenleaf, executive]

Well, as we've mentioned previously, David, we have patents on file with the U.S. FDA that have not -- or the U.S. Patent tradeoff that have not publicly been disclosed and won't be until we actually get some action, whether it's an acceptance of the patents or not. I can tell you that regardless of the U.S. label change and the U.S. label can be helpful to those patents in terms of Orange Book listing.

We started looking at that back when we on -- our extension study in general. And I would just leave you with now that it follows sort of that line of possibility in terms of those patents that are on file with the U.S. FDA. So the short answer is yes, but we haven't had a readout from the U.S. PTO yet.

[David Martin, analyst]

Got it. Second question, with restarts becoming more important and trending up, do you have a read on what percent of patients have the proteinuria rebound after coming off LUPKYNIS? And how long does it typically take for that rebound to occur?

[Peter Greenleaf, executive]

The short answer is -- and I would look to Greg if he's got a clinical answer to this. I think the data is emerging on this in terms of what we know internally in terms of seeing the percent of the patients come back. I'm not sure that we have a quantitative read as to how long that takes and what those proteinuria levels are.

What we do know is unfortunately the disease, and this isn't a LUPKYNIS issue. This is an MMF issue. This is a LUPKYNIS issue. It's any drug that comes after us until we get more alignment to treatment guidelines that it's treated episodically. And that when patients -- and some of this might be due to the fact that historical drugs had a lot of toxicity alongside of them that they used to treat the disease.

So trying to intermittently treat was a pattern that was just derived from trying to manage these potentially toxic drugs that were being put on the patients. But the short answer is we see this as continuing to be an opportunity as we shift the market more aligned to guidelines. Greg, what would you add?

[Gregory Keenan, executive]

At the end of our AURORA program, we monitored patients for subsequent 4 weeks. And there was stability with regard to the patient's response in terms of proteinuria for that subsequent 4 weeks. Thereafter, I certainly agree with you, Peter, that different individuals will have recurrence at different points.

And I'll just emphasize one thing. The opinion leaders in this area indicate like you are implying this is a chronic disease, not an episodic disease, irrespective about how clinicians treat it and hence, the recommendations to maintain treatment once they secure response is important.

[Operator]

Thank you. We reach the end of our question-and-answer session. I'd like to turn the floor back over to management for any further or closing comments.

[Peter Greenleaf, executive]

I want to thank everybody for their time today. Look forward to updating you as we move into the second quarter. Have a great day.

[Operator]

Thank you. That does conclude today's teleconference and webcast. You may disconnect your lines at this time, and have a wonderful day. We thank you for your participation today.