Vanda Pharmaceuticals (VNDA 1.25%)
Q4 2019 Earnings Call
Feb 25, 2020, 4:30 p.m. ET
Contents:
- Prepared Remarks
- Questions and Answers
- Call Participants
Prepared Remarks:
Operator
Ladies and gentlemen, thank you for standing by, and welcome to the Vanda Pharmaceuticals fourth-quarter 2019 earnings conference call. [Operator instructions] Please be advised that today's conference is being recorded. [Operator instructions] I'd now like to hand the conference over to your speaker today, Mr. Kevin Moran, vice president and controller.
Please go ahead, sir.
AJ Jones -- Chief Corporate Affairs Officer
Good afternoon. This isn't Kevin. This is AJ Jones, chief corporate affairs officer. But thank you so much, Liz, for that setup.
I do appreciate it. Good afternoon, everyone, and thank you for joining us to discuss Vanda Pharmaceuticals fourth-quarter and full-year 2019 performance. Our fourth-quarter and full-year 2019 results were released this afternoon and are available on SEC's EDGAR system and on our website, vandapharmaceuticals.com. In addition, we are providing live and archived versions of this conference call on our website.
Joining me today for this call is Dr. Mihael Polymeropoulos, our president and CEO; Kevin Moran, our controller and also incoming acting chief financial officer; Tim Williams, our general counsel; Gunther Birznieks, our chief business development officer and member of our R&D committee; and Jim Kelly, our outgoing executive vice president and chief financial officer. Following my introductory remarks, Mihales will give an update on our ongoing activities, and Kevin will review our financial results for the fourth-quarter and full-year 2019. I will then comment on our plans for 2020 before opening the lines for your questions.
Before I proceed, I would like to remind everyone that various statements that were made on this call will be forward-looking statements within the meaning of federal securities laws. Our forward-looking statements are based on current expectations that involve risks, changes in circumstances, assumptions and uncertainties. These risks are described in our Risk Factors and Management Discussion and Analysis of Financial Conditions and Results of Operations section in our annual report on Form 10-K for fiscal year ended December 31, 2018, and quarterly report on Form 10-Q for the quarter ended in September 30, 2019, which are available on the SEC's EDGAR system and on our website. Additional factors may be set forth in those sections of our annual report on Form 10-K for the fiscal year ended December 31, 2019, to be filed with the SEC in the first quarter of 2020.
We encourage all investors to read these reports and our SEC filings. The information we provide on this call is provided only as of today, and we will undertake no obligations to update or revise publicly any forward-leaning statements. We may also make on this call on account of new information, future events or otherwise, except by required by law. With that being said, I would now like to turn the call over to our CEO, Dr.
Mihaeles Polymeropoulos. Mihales?
Mihael Polymeropoulos
Thank you very much, AJ. Good afternoon, everyone, and thank you for joining us. 2019 was a transformative year for Vanda. We continue to drive strong growth and position the company for long-term success.
As we move in 2020, we are confident in our ability to build on great strides in our efforts to innovate for the benefit of all of our stakeholders, our patients, our employees, our shareholders and the broader communities that we serve. Before I go into our updates, I want to take a moment to highlight some of our key accomplishments in the last year. Looking first to our commercial products. I'm encouraged by the continued growth we see for HETLIOZ and Fanapt, in particular, our ability to achieve double-digit year-over-year product sales growth for HETLIOZ, six years now into launch, speaks volumes to the talent and dedication of our experienced sales team as well as the value both blind and sighted patients with Non-24 see in the treatment.
For Fanapt, we are pleased with the U.S. Supreme Court decision to deny the petition for a writ of certiorari that was filed by West Ward Pharmaceuticals, a subsidiary of Hikma, relating to our '610 Patent for Fanapt. This ensures the protection of the '610 Patent will remain through November 2, 2027. Additionally, we have made excellent progress around the launch of our direct-to-consumer marketing campaign for Fanapt, which is on pace to roll out in the first half of 2020.
Turning to our robust product pipeline and our ongoing efforts to propel innovation in clinical development. It is really an exciting time for Vanda with several late-stage indications and a number of critical milestones that are expected over the next 12 to 24 months. That said, I would like to start with tradipitant, our neurokinin-1 receptor antagonist, and provide an update on our ongoing programs. We reported a few minutes ago results of the EPIONE study of tradipitant in the treatment of pruritus in atopic dermatitis.
The EPIONE study did not meet its primary endpoint in the reduction of pruritus across the overall study population. However, the antipruritic effect of tradipitant was robust in the mild AD study population. Mild AD represents over 60% of the total atopic dermatitis population in the United States. The EPIONE study continued to demonstrate that tradipitant is safe and well-tolerated.
Although we are disappointed that EPIONE did not meet its primary endpoint, the profile of efficacy demonstrated in this study potentially addresses a highly unmet need for treating intractable pruritus for a large portion of AD patients. Due to their potent immunosuppressive effects, current systemic therapies for AD are typically only used in moderate to severe AD. The safe profile of tradipitant, coupled with a significant and immediate onset of itch reduction by the first full day of treatment may provide much-needed therapy for the majority of AD patients that experience mild AD lesion severity but still suffer from significant and severe pruritus. EPIONE was a randomized placebo-controlled Phase 3 study with 341 patients in the intent-to-treat population with severe pruritus with a range of disease severity presentation from mild, 23% of them; to moderate, 64%; and severe, 13% of patients, as determined by the Investigator's Global Assessment scale or IGA.
Patients were randomized 1:1 to receive either tradipitant or placebo for a treatment period of eight weeks. Patients were assessed at baseline and post-randomization with a number of symptomatic and disease severity scales performed at regular intervals. The EPIONE study examined the hypothesis that tradipitant dosed at 85 milligrams twice a day offers improvement of the disease symptoms and signs of AD over the evaluation period. At week eight, tradipitant and placebo patients demonstrated a significant and meaningful improvement in pruritus as measured by the Worst Itch Numeric Rating Scale, WI-NRS, but while the tradipitant margin of improvement was greater than that of a placebo, the difference between treatment groups was not statistically significant.
A significant interaction was observed between baseline disease severity, IGA one through four, and treatment, and that was significant with a p-value of 0.0004. This suggests the study participants with different baseline disease severity experienced different treatment outcomes. When accounted for that baseline disease severity and treatment interaction, a significantly larger improvement in WI-NRS was seen with tradipitant at the prespecified endpoint of week eight in the full trial population, and that was significant with a p-value of 0.0217. Similar effects were seen throughout the treatment periods at all post-randomization visits comprising weeks two, four, six, eight, and these data are summarized in Table 1 of the press release that you can see on our website.
Given the observed significant interaction between baseline disease severity and treatment, a subgroup analysis showed that patients with mild disease severity, 23% of the population with IGA scores of one and two, experienced the largest improvement over placebo. Specifically, in the mild AD group, tradipitant significantly improved WI-NRS over placebo at every visit. And this, again, can be reviewed in Table 1 of the press release and the associated Figure 1. The categorical WI-NRS responder analysis where patients are responding by four points or more showed that 72.5% of tradipitant patients had a clinically meaningful response, as compared to 33.3% of placebo patients, and that difference was significant as seen again in Table 1 with a p-value of 0.0007, highly significant.
These results suggest a large and significant antipruritic effect of tradipitant in mild AD and were confirmed with patient daily diary entries. For mild AD patients, the time course of response also showed that the antipruritic effect was seen immediately after the first full day of tradipitant dosing, suggesting a large and immediate therapeutic effect. Similar improvement was observed for nighttime sleep, often disrupted in patients with severe pruritus. Results from the EPIONE study, as shown in Figure 2 of the press release and the scientific literature, suggest that mild and severe AD types appear to be distinct endotypes with different sets of causative factors and course.
The American Academy of Dermatology atopic dermatitis guidelines list pruritus as an essential feature of atopic dermatitis. The significant pruritus associated with a mild type of AD and the worsening of lesions through scratching, along with sleep disruption, continue to represent a significant unmet medical need. The results of the EPIONE study suggest that tradipitant can produce a large and rapid antipruritic effect in mild AD. Currently, American Academy of Dermatology treatment guidelines indicate and recommend immunomodulatory medications only after topical regimens and phototherapy are found not to adequately control the disease.
A well-tolerated systemic antipruritic agent with rapid onset of action, like tradipitant, could add significant value to patients and take a primary place in the treatment algorithm of atopic dermatitis patients. The results of the EPIONE study will need to be confirmed in a follow-up study. Vanda is currently conducting EPIONE 2, and we plan to reassess the design of this study as we continue to analyze the results of EPIONE and determine the next steps. Briefly, I would like to touch upon our other pipeline projects before I turn over the call to Kevin.
On gastroparesis, our study of tradipitant in that indication, that's a Phase 3 study, continues to enroll and randomize patients who suffer from both idiopathic and diabetic gastroparesis. To remind you, following the completion of a Phase 2 study in our motion sickness program with tradipitant as well, last year, we have now begun to recruit for a large Phase 3 study of patients with motion sickness. We expect to complete this program in motion sickness and file a new drug application with the FDA, hopefully, by the end of the year. In the new year, we also continue to aggressively drive forward other exciting indications.
On HETLIOZ, Vanda submitted an application for the Smith-Magenis Syndrome, along with a liquid formulation to be accepted by the FDA for review in 2020. For the treatment of Jet Lag Disorder, we continue our engagement with the FDA to resolve the issues that preclude approval, and we remain confident that our supplemental NDA for Jet Lag Disorder demonstrates the significant and clinically meaningful effects of HETLIOZ in the core features of Jet Lag Disorder that are required to demonstrate substantial evidence for approval in that indication. An observational study of delayed sleep phase disorder, DSPD, is ongoing, and we expect to initiate a Phase 3 intervention study in DSPD in 2020. Briefly, to touch upon Fanapt, our atypical antipsychotic in schizophrenia, a Phase 3 study in bipolar disorder has been initiated as well as the pharmacokinetic study of long-acting injectable formulation on Fanapt is ongoing.
I'll stop here with this update and turn the call over to Kevin. And welcome, Kevin.
Kevin Moran -- Vice President and Controller
Great. Thank you, Mihales. So I'll begin by summarizing our exceptional full-year 2019 financial results before turning to discuss the fourth quarter of 2019. Total revenues for the full-year 2019 were $227.2 million, an 18% increase, compared to $193.1 million for 2018.
HETLIOZ product sales of $143 million were the primary contributor and driver of our 2019 revenues and saw a 23% growth compared to 2018. Fanapt product sales of $84.2 million reflects 9% growth compared to 2018. For the full-year 2019, Vanda reported a net income of $115.6 million, compared to a net income of $25.2 million for 2018. The income tax benefit of $86.5 million reflected in the financial results for the full-year 2019 includes the favorable impact of the release of Vanda's deferred tax asset valuation allowance, which occurred in the third quarter of 2019.
This onetime tax benefit is a noncash item and, therefore, does not have an immediate impact on Vanda's cash balance. Vanda's cash, cash equivalents, and marketable securities, referred to as cash, as of December 31, 2019, were $312.1 million, representing an increase of $54.8 million to cash during 2019. Turning now to our quarterly results, total revenues for the fourth quarter of 2019 were $60.9 million, a 15% increase, compared to $53 million in the fourth quarter of 2018. HETLIOZ net product sales were $38.6 million in the fourth quarter of 2019, a 19% increase, compared to $32.4 million in the fourth quarter of 2018.
The HETLIOZ patients on therapy number grew in the fourth quarter as compared to the third quarter of 2019. During 2019, we saw a downward and favorable Medicaid payer mix trend that resulted in higher net revenue per unit. As of December 31, 2019, the specialty pharmacy channel held less than two weeks of inventory as calculated based on trailing demand. Specialty pharmacy's inventory on hand at the end of the fourth quarter of 2019 was higher when compared to the third quarter of 2019.
The value of this inventory change was approximately $300,000. Fanapt net product sales of $22.3 million in the fourth quarter of 2019 reflect an 8% increase, compared to $20.6 million in the fourth quarter of 2018. As of December 31, 2019, wholesalers have increased inventory on hand when compared to the third quarter of 2019. The value of this inventory change was approximately $100,000.
Fanapt prescriptions, as reported by IQVIA Xponent, decreased by approximately 3% in the fourth quarter compared to the fourth quarter of 2018. In the fourth quarter of 2019, Vanda reported a net income of $4.2 million, compared to a net income of $10.4 million for the fourth quarter of 2018. Operating expenses in the fourth quarter of 2019 were $56.7 million, compared to operating expenses of $43.9 million in the fourth quarter of 2018. The $12.8 million increase was a combination of higher Non-24 awareness, corporate and legal costs.
Vanda expects to achieve the following financial objectives in 2020. Net product sales from both HETLIOZ and Fanapt of between $240 million and $260 million, HETLIOZ net product sales of between $155 million and $165 million, Fanapt net product sales of between $85 million and $95 million, year-end 2020 cash of greater than $320 million. Of note, our HETLIOZ net product sales guidance is based on our currently approved FDA indication for Non-24. We expect first quarter 2020 HETLIOZ revenue to be impacted by the seasonal Medicare manufacturer contribution and the annual payer disruption linked to new plan years, plan changes and reauthorizations, which we witnessed in prior years.
We expect both R&D and SG&A operating expenses to rise in 2020 as compared to 2019 spending levels. The primary contributions to the 2020 growth in spend include commercial DTC programs on Fanapt and HETLIOZ and an increase in R&D activities related to our late-stage clinical programs for tradipitant, Fanapt, and HETLIOZ. That said, we expect to continue our trend of adding to our year-end 2020 cash balance while advancing our portfolio of investments in support of patients. I'll now turn the call back to AJ Jones to discuss Vanda's 2020 plans.
AJ Jones -- Chief Corporate Affairs Officer
Thank you, Kevin, and welcome again. In 2020 for HETLIOZ, we will continue to advance the commercialization of HETLIOZ for Non-24 in the U.S. and also in Germany and further execute our commercial plans in new EU markets. For Fanapt, we will continue to expand commercial support for Fanapt for schizophrenia in the U.S.
As relates to R&D, we will continue our clinical and commercial activities in support of tradipitant. We will also advance the life cycle management of HETLIOZ, both in R&D and also commercial activities, including SMS, which was mentioned earlier. We will also advance Fanapt's life cycle, as well as continued R&D and also commercial activities. For our early stage, both VQW051, VTR-297 and also CFTR, we will continue to move those along the clinical paths and programs that have been announced.
Additionally, we will also have other business objectives related to our IP and our additional IP and portfolio support all of our products. We will also invest heavily as well in terms of hiring, in terms of human capital to ensure the advancement of our scientific innovation and also to develop core competencies toward our long-term growth as our company. With that being said, I will now turn the call over back to Mihales. Mihales?
Mihael Polymeropoulos
Thank you very much, AJ and Kevin. At this time, we'll be happy to answer any questions you may have.
Questions & Answers:
Operator
[Operator instructions] Our first question comes from the line of Chris Howerton with Jefferies. Your line is now open.
Chris Howerton -- Jefferies -- Analyst
Great. Thanks so much for taking the questions and congrats on the great commercial year last year. So for, I guess, top of mind, given that atopic dermatitis results were released today, and that it appears to have a beneficial effect in the mild patients. What would be the realistic outcome here, do you think that you could change the second Phase 3 trial to focus more on the mild patients and that would be the regulatory path forward or what are some other options that we can think of in terms of consideration of moving forward to that program?
Mihael Polymeropoulos
Certainly. So first of all, the summary of the results is that the hypothesis that tradipitant is an antipruritic agent across the spectrum of severity of AD has not been confirmed. However, for people with a mild type of AD it appears that tradipitant has a strong antipruritic effect and does so early in the clinical meaningful way. The way we think about these results, Chris, is that there are two signs to ignore, meaning that while the headline, of course, is unfortunate and disappointing.
So the EPIONE study did not confirm that blocking the actions of substance speed through NK1 receptors will be of significant therapeutic effect to all AD patients. Nonetheless, the effect is large as it appears in the study. The results of the study would need to be confirmed to be certain that both the result is reproducible and second, that the magnitude is reproduced as well. If so, we certainly understand from discussions with experts in the field that this could fit a significant unmet medical need in an area that the atopic dermatitis field is not concentrating today.
New treatments are concentrating to treat primarily the lesions seen in moderate and severe patients. But certainly, there is no other effort for a systemic, safe antipruritic treatment for patients with mild disease. So what does that mean for Vanda's program? The EPIONE 2 study is in early phases, which means it can be efficiently reassessed and adapted to be shifted toward the population that we think the drug likely has the larger effect, and that is the mild population. Another consideration that our experts are urging us to look at is whether the drug would have an effect in the population of 12- to 18-year olds, a population that primarily has the mild type of AD associated with severe pruritus.
And for which, there are no approved, safe, systemic treatments. We all know that mild treatment is treated with good skin hygiene, emollients and also local creams, including calcineurin inhibitors and crisaborole. So in that population, a systemic safe antipruritic treatment can play a significant role. So Vanda's plan is to continue to analyze the EPIONE wealth of data, quickly reassess how we can best utilize the ongoing EPIONE 2 study, which can be streamlined.
And by that, I mean that with the results of the markings we see, fewer patients will be needed to evaluate whether or not the results in EPIONE is confirmed. And to be certain that we also answer the regulatory question, what does it mean if you succeeded to confirm this result. I would say it depends. Typically, the regulatory agencies would require two confirmatory studies.
But of course, it depends on the magnitude of results upon confirmation. So I will leave it there, and I'm sure we'll have more to say about that in the coming quarters.
Chris Howerton -- Jefferies -- Analyst
OK. OK. That makes sense absolutely. OK.
And then it was, at least in my mind, conspicuously not mentioned, but there was obviously interaction with the FDA with respect to the long-term toxicology requirement for a nine-month dog study. And clearly, there was a court decision recently with respect to that. So has there been any additional interactions between Vanda and the FDA on this program? And what updates can you provide to us with respect to strategy?
Mihael Polymeropoulos
Yes. So to recap and summarize for all our audience, Vanda has disputed the necessity of an additional nine-month dog study as a preclinical additional toxicology study on top of all the toxicology studies that have been done without any significant safety signals that could inform human studies. Of course, the FDA disagreed with that. Our dispute went to court.
The court decision recently agreed with the FDA that while they have not provided evidence that this study should be required and how is it predictive for human safety, the court nonetheless agreed with the FDA that they have the authority to decide whether to require such study or not. We continued discussions with the FDA, we evaluate a number of options that include regulatory paths but also even additional paths. So I'm not going to specifically address today. So our view is that we have a number of options in front of us.
And we remain optimistic that we will identify a suitable solution.
Chris Howerton -- Jefferies -- Analyst
OK. And I certainly respect that you are not prepared to discuss those strategic options right now. But when can we expect more color or information on that strategy? Just, I guess, as discussions progress with the FDA? Or is there something internally that needs to happen to kind of be able to put that forward?
Mihael Polymeropoulos
Well, I will say, we'll give the update when we have the update.
Chris Howerton -- Jefferies -- Analyst
OK.
Mihael Polymeropoulos
But certainly, there are a lot of things in the process, specifically with the FDA that we hope we can make some strides.
Chris Howerton -- Jefferies -- Analyst
OK. And then maybe just one last question from me, also regulatory, maybe you could just describe again what the package is for SMS? And what has been your interactions with the FDA with respect to that package?
Mihael Polymeropoulos
So the packages we discussed before, the core part of that package is the single Phase 3 study. That was a study that we discussed, a crossover design. The results of this study have been discussed with the FDA in a pre-NDA meeting, and we agreed on what we will submit. We have submitted and we're waiting for this package to be filed.
And it has two components. One is the Phase 3 clinical data but also a separate sNDA on a liquid formulation. I remind you that that study was conducted in both adults and children, and it included both the current capsule formulation and the proposed liquid formulation.
Chris Howerton -- Jefferies -- Analyst
OK. OK. Great. Well, thank you so much, Mihales, for taking the questions, and I'll hop back in the queue.
Mihael Polymeropoulos
Thanks, Chris.
Operator
Our next question comes from the line of Jason Butler with JMP Securities. Your line is now open.
Unknown speaker
Hi. It's Roy in for Jason. Thanks for taking our questions. I had a few on EPIONE, I guess.
Can you tell us what the baseline Worst Itch scores were for the mild versus the moderate and severe patients for treatment groups? And then, I guess, is it possible that any concomitant medications or other treatments confounded the results in moderate to severe patients?
Mihael Polymeropoulos
So I will answer the last one. We do not believe that any concomitant medications have confounded. So we truly believe that the severity type is actually true and not confounded finding within that population. I would refer you for the first one to the Figure 2 in the press release, and that would be in Box B, you will see some baseline parameters broken by IGA one, two, and IGA three, four.
And your question, Worst Itch-NRS, is that at baseline, all patients were required to have an average Worst Itch score of seven in a grading 0 to 10 scale. And you can see here that the average was 7.2 in the IGA one, two group and 8.3 in the three, four.
Unknown speaker
OK. Great. And then as far as 2020 guidance for HETLIOZ, it kind of suggests slowing growth. Can you describe what the main driver or drivers of that is? Thanks.
Mihael Polymeropoulos
Well, it is true that if you calculate backward and back out the price, which you've done already that although we guided at the upper end on a double-digit growth like we had a double-digit growth this year, certainly those numbers are smaller. It is the first quarter. There are many things to know. We are six years into the launch.
And as you know, it is very, very unlikely that products are in a rare orphan disorder will continue to grow like we've seen HETLIOZ. However, while we still forecast growth in the Non-24 business the initiatives that we have ongoing and hopefully, we'll expand in the coming quarters, we believe that they can add to that growth. Specifically, I would like to speak toward one of them. As we have discussed in the past, Non-24 disorder that can be co-morbid not only with psychiatric disorders that we've spoken about in the last couple of years but also in patients with traumatic brain injury.
And traumatic brain injury is a large number of patients with mild to severe concussions that have a remaining sleep-wake disorder, many types of the Non-24 type. That association with TBI is well-known and described in the Diagnostic and Statistical Manual 5 of Psychiatric Disorders. What we're doing toward that is we're exploring with neurologists their understanding, interest, and awareness around the presence of Non-24 in TBI patients. This is a very early project, but you should expect us that our sales force and marketing will make a significant effort to identify and treat these patients.
So that's one example of initiatives. And of course, we are very keen to see Smith-Magenis syndrome indication approved, so that will allow us to market directly to the families and patients with SMS. And we said in the past, we appreciate our long-standing multiyear relationship with the organization, PRISMS, the key advocacy organization for several hundred families in the U.S.
Unknown speaker
OK. Great. Thanks for taking the questions.
Mihael Polymeropoulos
Thanks, Roy.
Operator
Our next question comes from Derek Archila with Stifel. Your line is now open.
Unknown speaker
Hey. Great. Thanks, guys. This is Ben on for Derek.
Thanks for taking my call. Just wondering if you can share when data are expected for this Fanapt PK study?
Mihael Polymeropoulos
The pharmacokinetic study is ongoing, but I can give you the preview that the early data suggest a profile that will be compatible with the long-acting injectable. So while we're continuing to learn and finalize the pharmacokinetic study, we're actually in the early stages of designing our Fanapt schizophrenia efficacy study with a long-acting injectable.
Unknown speaker
OK. Thanks. And then one more from us, just in light of the DTC spend campaign for Fanapt, how should we think about OPEX for this year and then possibly in 2021 as well? Thanks.
Mihael Polymeropoulos
As you noticed, we have not given a specific number for OPEX. We're guiding for a cash balance at the end of the year to exceed 320. Now as we have said, actually, in the past quarter, we expect that the OPEX sequentially will be increased due to an intensified direct-to-consumer campaign, including the Fanapt campaign, but also the number of studies that we're pursuing in R&D.
Unknown speaker
OK. Thanks for the information.
Mihael Polymeropoulos
Sure.
Operator
Our next question comes from Joel Beatty with Citi. Your line is now open.
Shawn Egan -- Citi -- Analyst
Hi, guys. This is Shawn Egan calling in for Joel. A few from our team. Following the results from EPIONE, what is the team's current hypothesis on why it could be effective in mild patients versus the more severe? And I know you mentioned that the mild setting, these patients are typically treated with immunosuppressive agents.
Could that be impacting or maybe just your high-level views on that?
Mihael Polymeropoulos
Yes. That is actually a question that, of course, there is not a complete answer. However, the prevailing literature today suggests that atopic dermatitis is a complex disorder and heterogeneous. In that, there are different types with different causality and different course.
So that mild AD is not in atopic dermatitis with mild symptoms, but rather a distinct what is called endotype. In fact, we have some references in our press release on that. Both patients in mild AD and severe ad, they experience severe pruritus. So while they are characterized clinically by different types of lesions, mild AD has milder lesions, the severe AD has more severe lesions with a higher extent.
The symptom of pruritus, nonetheless, is severe in both of them or can be severe in both of them. Now speaking toward the endotype, what do we begin to understand, and in fact, we are conducting a very large analysis in the entire population of over 800 patients that we screened into the AD looking both at biomarkers, but also the genetics of these individuals have now completed a whole genome sequencing analysis in every patient in the study. What we're identifying some of it is presented in figure two in the associated press release. In Panel C, you will see In Panel C, you will see the description that it appears that patients with IGA one and two had a lower eosinophil count as compared to patients than IGA three and four.
And what is very significant is that eosinophil count appears to be a marker of a disease, not a marker of a disease state. So that patients who have higher eosinophil count upon improving their blood eosinophil count does not become lower. So that is one very interesting endotype. The second one and it comes from generics, it appears that patients with IGA one and two do not have an accumulation of filaggrin mutations.
This is a protein whose gene has been shown to be mutated frequently in patients with atopic dermatitis, filaggrin constituting a protein in the skin barrier. So what you see in our set and it is beginning to be demonstrated in the literature as well. The patients with one and two do not have an accumulation of inherited causes of his skin barrier mutations. So it comes down now to the question, why would an NK-1 antagonist work better in IGA one and two than three and four.
The hypothesis scales as follows, that substance speed may be a prominent mediator of itch in patients with atopic dermatitis in a skin that does not have the inflammatory response and immune over action that you see in it IGA three and four. In IGA three and four in severe lesions, we all know now that interleukin-4, interleukin-13 and the presence of other cytokines summon an entire response with secondary agents that increase it. So besides substance speed, you will have histamine, serotonin, NGF in a number of site propruritic cytokines. So most probably, the substance P contribution gets flooded by other pruritogenic agents in the three and four, that is why, while, of course, we do see response, the response is not prominent, and it's not significantly better than what you see with placebo.
Shawn Egan -- Citi -- Analyst
Got it. Thank you. I really appreciate the color on that. Maybe another question on HETLIOZ, just kind of shifting gears a little bit.
In the delayed sleep-wake phase disorder, have you done much work, kind of understanding the awareness for the indication? And maybe you could help us understand how high the unmet need is and how these patients are typically treated currently?
Mihael Polymeropoulos
So DSPD is actually a condition that may affect in different studies from a half to several percentages of the population. And as we know, it's more prominent in adolescents and young adults. What is very interesting, people can self diagnose very quickly, calling themselves night owls or a difficulty getting up in the morning and being consistent. Often, people who have trouble getting up to go to school or go to work, but they have no trouble sleeping eight or nine hours when they left to initiate sleep on their own schedule.
And typically, that is in the early morning hours, two, three o'clock in the morning. So that's about prevalence and self-diagnosis. When things get worse and DSPD impacts the occupational and social functioning of these patients, they seek treatment. Unfortunately, there is very little to treat them with, because sleep agents may help you follow sleep, but they will not do anything to the circadian cycle and, in fact, worsen it.
The work we're doing now is also inspired by the work of Michael Young at Rockefeller, who is a Nobel Prize winner a couple of years ago, having discovered a prominent mutation in humans with DSPD mutation. That is mutation in the CRY1 gene. And we're actually following up with that with an observational study in Turkey, where these families came from in a collaboration with investigators in Ankara. And we're learned a lot about the expression of DSPD there.
And also, we're doing a similar study with DSPD patients in the U.S. Our goal is to conduct an integrationla study, both in patients with CRY1 mutation and without CRY1 mutation and begin to characterize the effect of tradipitant in that population.
Shawn Egan -- Citi -- Analyst
Perfect. And then my last question is that just with Jim leaving, will there be any kind of changes in the corporate strategy at Vanda going forward?
Mihael Polymeropoulos
Everything will be even better. Nothing immediate, but I would like to take the opportunity and really thank Jim for 10 years of tireless work; building a significant part of the company, both on commercially and being – encouraging the development of our compounds; and, of course, putting up with the communication with all of you guys and doing an excellent job. Thank you, Jim. Jim, why don't you say something?
Jim Kelly -- Outgoing Executive Vice President and Chief Financial Officer
Alright. Well, I'll take the moment to thank Mihales for bringing me on board 10 years ago and being a part of everything that we've built and accomplished, Mihales and this entire team. I will certainly miss all my colleagues, past and present, and have enjoyed interacting with yourselves, the analysts and the investment community, and I look forward to watching great progress here at Vanda in years to come.
Mihael Polymeropoulos
Thanks, Jim.
Operator
I'm showing no further questions in queue at this time. I'd like to turn the call back to Dr. Polymeropoulos for closing remarks.
Mihael Polymeropoulos
Yes. Thank you very much for joining us. Plenty to be discussed on EPIONE in upcoming scientific meetings. And certainly, we look forward to updating you on all our programs next time.
Thank you.
Operator
[Operator signoff]
Duration: 49 minutes
Call participants:
AJ Jones -- Chief Corporate Affairs Officer
Mihael Polymeropoulos
Kevin Moran -- Vice President and Controller
Chris Howerton -- Jefferies -- Analyst
Unknown speaker
Shawn Egan -- Citi -- Analyst
Jim Kelly -- Outgoing Executive Vice President and Chief Financial Officer