Ladies and gentlemen, thank you for standing by, and welcome to the Harmony Biosciences fourth quarter and full year 2020 financial conference call. At this time, all participant lines are in a listen-only mode. After the speaker's presentation, there will be a question and answer session. To ask a question during the session, you will need to press star one on your telephone. Please be advised that today's conference is being recorded. If you require any further assistance, please press star zero. I would now like to hand the conference over to your speaker today, Lisa Caperelli. Thank you. Please go ahead, ma'am. Thank you, operator. Good morning, everyone, and thank you for joining us today as we review Harmony Biosciences fourth quarter and full year 2020 financial performance and provide business updates. Before we begin, I encourage everyone to go to the Investor section of the Harmony Biosciences website to find the press release and slides that accompany our discussion today, including a reconciliation of the GAAP to non-GAAP financial measures. At this stage of our company life cycle, we believe non-GAAP financial results better represent the economics of our business. Our presenters on today's call are John Jacobs, CEO, Dr. Jeff Dayno, Chief Medical Officer, Jeffrey Dierks, Chief Commercial Officer, and Susan Drexler, CFO. As a reminder, we will be making forward-looking statements today which are based on our current expectations and beliefs. These statements are subject to certain risks and uncertainties, and our actual results may differ materially. I encourage you to consult the risk factors discussed in our SEC filings for additional details. At this time, I'd like to turn the call over to our CEO, John Jacobs. John? Thank you, Lisa. Good morning, everyone, thank you for joining us. At Harmony, we are focused on developing and commercializing treatments for patients living with rare neurological disorders who have unmet medical needs. With a differentiated product profile and unique attributes of our commercial product, WAKIX, we are providing an important new treatment option for adult narcolepsy patients and the healthcare professionals who treat them. I am very pleased with the market adoption of WAKIX, as indicated by our strong first full year of commercial sales, approximately $160 million, as well as the achievement of several clinical and regulatory milestones in our Life Cycle Management Program, all of which were possible due to the dedication, commitment, passion, and drive of the entire team at Harmony. These accomplishments not only affirm our three pillars of growth strategy and highlight the opportunity that WAKIX represents as a treatment for narcolepsy, but also serve as the foundation from which we expect strong year-on-year performance that will drive future value for the patients we serve and for our shareholders. It goes without saying that 2020 was the most challenging year that many of us will ever face in our lifetimes, as we all navigated the complexities and constraints of an unprecedented global pandemic. Despite these challenges, and in the face of adversity, the Harmony team persevered to drive WAKIX sales growth, achieve regulatory milestones, advance clinical programs, and migrate the company from private to public, making 2020 the most productive year yet in our company's history. With the additional gross proceeds of $147.6 million from our IPO and subsequent listing on the Nasdaq Global Market and Russell 2000 and Russell 3000 indices, we strengthened our financial position and increased visibility with investors, laying the foundation for us to enter 2021 well-positioned to advance and execute upon all three pillars of our growth strategy. Let me share with you the progress we've achieved in 2020 on our three pillars of growth. Pillar number one, optimize the commercial launch of WAKIX. In 2020, we engaged with healthcare providers and patients to expand the awareness and utilization of WAKIX in narcolepsy and drive demand, which resulted in strong growth with Q4 2020 revenue of $56.3 million and full-year revenue of approximately $160 million. Late last year, we expanded the utility of WAKIX by gaining approval of the cataplexy indication in adult patients with narcolepsy, which has been well received by both the healthcare providers and patient communities. As you'll hear during our commercial overview, we are seeing continued increases in the average number of patients on WAKIX and the number of healthcare professionals prescribing WAKIX, which is driven by the truly differentiated product profile that WAKIX offers. Let's move on to Pillar number two, expand the clinical utility of WAKIX. Based on the unique mechanism of action of pitolisant, we believe we have a portfolio and a product opportunity, and our clinical team has made extensive progress on the key clinical programs that represent new opportunities for us to help patients beyond narcolepsy. Late last year, we initiated and enrolled the first patient in our phase II trial in patients with Prader-Willi syndrome. We are excited to collaborate with the Prader-Willi patient and medical community to explore treatment options that do not currently exist for these patients to address their unmet medical needs. In addition, our team submitted an IND for a Clinical Development Program in myotonic dystrophy. With the IND now open, we are on track to initiate a phase II trial in patients with DM1 during the first half of this year. Throughout the year, we highlighted the strong clinical data for WAKIX with the medical community through the presentation of multiple posters at the annual sleep conference and other medical meetings. Lastly, our efforts are on track toward initiating a phase III trial in pediatric patients with narcolepsy later this year. Based on this progress, pitolisant is poised to be evaluated in three late-stage trials during 2021. Finally, our third pillar, acquire new assets to expand our portfolio. Though WAKIX alone represents a significant growth opportunity for Harmony, in line with our strategy for growing the company and accelerating long-term value accretion for our shareholders, we intend to acquire additional assets to expand our portfolio beyond WAKIX. Our dedicated business development team is continuing to focus their efforts on pursuing the acquisition of additional assets, co-development and/or co-promotion opportunities that would be complementary to our existing commercial footprint and core areas of expertise. As we enter 2021, we believe that Harmony is very well-positioned financially and strategically to continue to grow by executing on all three pillars of our growth strategy, which will enable us to achieve our objectives as an organization and ultimately to serve patients through the continued development and introduction of innovative therapies. With that, I'll turn the call over to Jeff Dierks to provide a commercial update. Jeff? Thanks, John. As John mentioned, 2020 was an outstanding year for Harmony. Fourth quarter results were strong as we continued to build on our successful launch performance from the first three quarters of 2020. Now, before I delve into our commercial performance, I'd like to spend a minute to touch on the narcolepsy market opportunity for WAKIX. In 2020, the adult narcolepsy market value grew 16%, with net sales of approximately $2.1 billion. We expect the market to continue to grow through an increase in diagnoses, investment in education, and the introduction of new products. There are approximately 165,000 people living with narcolepsy in the U.S., with about 72,000 of them currently diagnosed. Of the 72,000 people diagnosed with narcolepsy, approximately 44,000 of them are currently on treatment, and the other 28,000 are electing not to receive any type of treatment. Despite the multiple narcolepsy drugs that were available on the market before WAKIX, many diagnosed patients either refuse treatment, or those who are on treatment experience residual symptoms and communicate low- levels of satisfaction. We believe that WAKIX offers a meaningfully differentiated treatment option for the broad adult narcolepsy patient population, both the undiagnosed population, as well as the large existing diagnosed population that is either untreated or not satisfied with their current treatment options. The positive feedback that we are hearing about the difference we are making in the narcolepsy community centers around the following key differentiating attributes of WAKIX that are both meaningful and aligned to the unmet needs of the market. WAKIX is a first-in-class molecule with a novel MOA, the only selective H3 receptor antagonist/inverse agonist approved by the FDA. It is the first and only FDA-approved non-scheduled treatment indicated for Excessive Daytime Sleepiness, also known as EDS, or cataplexy and narcolepsy. WAKIX is not a stimulant, with no evidence of drug tolerance or withdrawal symptoms in clinical studies. WAKIX can be used as monotherapy or administered concomitantly with other narcolepsy treatments, with no clinically relevant pharmacokinetic interactions with either modafinil or sodium oxybate, as demonstrated in clinical trials. Lastly, WAKIX offers convenient, patient-friendly, once-daily oral tablet administration in the morning upon wakening. Turning to our commercial performance. Net revenues for Q4 grew to $56.3 million. This represents another quarter of greater than 20% growth in net sales, despite the continuing effects of the pandemic. Our growth is predominantly driven by demand, as well as the price increase that was taken towards the end of last year following the approval of the cataplexy indication. 2020 was our first full year of commercialization, and we achieved recognizable first-year net revenues of approximately $160 million. With the majority of our customer interactions this year with healthcare professionals, patients, and payers occurring virtually, our strong performance reflects not only the resilience and commitment of our team and the overall benefit-risk profile of WAKIX, but also highlights the significant unmet need in the narcolepsy market and the value of WAKIX to the narcolepsy community. In line with pillar one, an important goal for Harmony is driving growth through our launch of WAKIX. I'd like to highlight three key performance metrics from Q4. First, we continue to increase the average number of WAKIX patients. The average number of patients on WAKIX in Q4 were approximately 2,500. This growth demonstrates continued adoption of WAKIX. Second, the WAKIX prescriber base continued to increase, with more than 2,400 unique healthcare professionals having prescribed WAKIX since launch through the end of 2020. This represents almost 30% of the approximately 8,000 healthcare professionals who treat the diagnosed narcolepsy population. Third, market access for WAKIX continues to be strong. We have secured formulary access for approximately 80% of all U.S. insured lives across commercial, Medicare, and Medicaid. Within these covered lives, we have observed additional favorable market access for WAKIX subsequent to the expanded approval of WAKIX for treatment of cataplexy in adult patients with narcolepsy in October of 2020. As a result of the cataplexy label expansion, in Q4, we've seen an increase in the percentage and volume of prescription requests for narcolepsy patients with cataplexy or Type 1 narcolepsy. In addition, some managed care plans made positive formulary policy changes for patients, accelerating a patient's ability to get access to WAKIX. From the medical community, we're hearing positive feedback on the cataplexy data and the preferred use of WAKIX as a first-line treatment for cataplexy compared to other agents due to its safety profile. We are pleased with the early positive signs seen with the cataplexy label expansion and look forward to continuing to drive growth in narcolepsy patients suffering with EDS or cataplexy. In summary, I'm extremely proud of our fourth quarter and full year performance. We remain focused on supporting adult narcolepsy patients and delivering significant near and long-term growth as we continue to execute and build on our WAKIX launch in 2021 and beyond. I will now turn the presentation over to Dr. Jeff Dayno for an update on our Clinical Development Program. Jeff? Thank you, Jeff. Good morning, everyone. I am pleased to share with you this morning the significant progress that we made during the fourth quarter of last year in our Clinical Development Programs, including initiation and first patient enrolled in a phase II clinical trial in patients with Prader-Willi syndrome, or PWS, and the submission of an IND for our Myotonic Dystrophy Development Program late last year, two milestones that we targeted and achieved in 2020. Both of these events represent the acceleration of Harmony's clinical development efforts and advancement of the Life Cycle Management Plan for pitolisant. Before I provide a little detail on these programs, I would first like to frame the opportunity in front of us. Based on its unique mechanism of action, we view pitolisant as a portfolio in a product opportunity and have taken a mechanism-based approach to drug development. These Life Cycle Management Programs with pitolisant have us active in several orphan rare neurological disease patient populations, pursuing multiple potential new indications. As John mentioned in his opening remarks, we intend to have three phase II or III trials in the clinic by year-end, a goal that my team and I are excited about, focused on, and actively working towards. Let me start with our development program in Prader-Willi syndrome. PWS is a pediatric orphan rare CNS and multisystem disorder due to hypothalamic dysfunction. It affects approximately 15,000 to 20,000 patients in the United States. In addition to the primary symptom of hyperphagia, which is defined as an abnormally increased appetite for and consumption of food, over 1/2 of PWS patients also experience Excessive Daytime Sleepiness, or EDS, which is the primary focus of our development program with pitolisant. Other than growth hormone, there are no approved treatments for the majority of symptoms of PWS, including E xcessive D aytime Sleepiness. We are taking a very different approach than other PWS development programs, which have focused on hyperphagia as the primary outcome, because we are studying the effects of pitolisant on EDS in patients with Prader-Willi syndrome. Our rationale is based on the following. First, like narcolepsy, PWS is a disorder of hypothalamic dysfunction. Some of the manifestations of sleep-wake state instability associated with PWS are similar to those in patients with narcolepsy. In fact, some patients with PWS have a narcoleptic phenotype. Second, some patients with PWS have decreased levels of hypocretin, also known as orexin, the main neuropeptide that mediates sleep-wake state stability, and decreased levels of hypocretin is one of the diagnostic features of Type 1 narcolepsy. Third, pitolisant has already demonstrated efficacy in improving EDS in patients with narcolepsy. This is thought to be related to its unique mechanism of action of increasing histamine levels in the brain, a major wake-promoting neurotransmitter that also serves to help stabilize states of sleep and wakefulness, similar to hypocretin or orexin. Lastly, histamine is also felt to be an important neurotransmitter in the brain that helps support other key functions, including attention, vigilance, and cognitive function. Preliminary evidence from both animal and human studies suggests that pitolisant could have a positive effect on these functions as well. With that as background, I will walk you through the design of the phase II clinical trial in patients with PWS that we initiated last December, which has generated much interest in both the patient and medical communities. It is a randomized, double-blind, placebo-controlled trial designed to assess the safety and efficacy of pitolisant in patients with PWS ages 6- 65. This trial is currently enrolling with a plan to randomize approximately 60- 70 patients at 10 sites in the U.S. Patients are being screened. Eligible patients are randomized to receive one of two doses of pitolisant or placebo. The treatment period in the randomized controlled phase is 11 weeks, consisting of a three-week titration period followed by eight weeks of stable dosing. Patients who complete the randomized controlled phase of the trial will be eligible to participate in an open label extension phase to assess the long-term safety and effectiveness of pitolisant. The primary objective of the trial is to assess improvement in EDS as measured by the Multiple Sleep Latency Test, or MSLT. Secondary objectives include the following. Caregiver assessment of symptom severity based on EDS, clinician-rated assessment of overall PWS symptom severity, evaluation of behavioral scales, assessment of cognitive function, and overall caregiver burden. Top-line results from this trial are anticipated in the first half of 2022. Another development program that we have advanced is myotonic dystrophy. Myotonic dystrophy, or DM, is another orphan rare CNS disorder and is the most common form of muscular dystrophy in adults. It affects approximately 150,000 patients in the U.S. There are two types of DM, also known as DM1 and DM2. DM1 is much more common than DM2, has an earlier onset of disease symptoms, and the symptoms are more severe in patients with DM1 compared to DM2. The primary symptom in patients with myotonic dystrophy is myotonia, which is an inability of muscles to relax. However, beyond the muscular symptoms of DM, the most common symptom in these patients is EDS, which is experienced in 80% to 90% of DM patients and causes significant impairment in daily functioning. Two other common symptoms, which are also thought to be the result of impaired CNS histamine signaling, are fatigue and cognitive impairment. Patients with DM also report that these symptoms have significant impact on their overall functioning. There are no approved treatments for patients with myotonic dystrophy, this represents a significant unmet medical need. We believe that pitolisant could be effective for the symptom of EDS in patients with DM based on its demonstrated efficacy in improving EDS in adult patients with narcolepsy. In addition, the triad of EDS, fatigue, and cognitive dysfunction in patients with DM are likely the result of impaired histaminergic signaling in the brain. The fundamental scientific rationale of why we believe pitolisant could have clinical utility for these symptoms is because pitolisant works to increase histamine signaling in the CNS. In line with our development milestones, we submitted an IND to FDA last December and have received a Study May Proceed letter from the agency which opened the IND. Therefore, we are on track to initiate our phase II clinical trial in patients with DM1 in the first half of this year. We will provide more details about this study at that time. Lastly, the third development program that we plan to have in the clinic by year-end is pediatric narcolepsy. We will be engaging with FDA to discuss our pediatric study plan, and that interaction will inform the design of the trial. We look forward to sharing more detail about this program with you during the second half of this year. In closing, Q4 of 2020 marked the acceleration of our Clinical Development Programs at Harmony and advancement of our Life Cycle Management efforts for pitolisant. Based on its unique mechanism of action, we view pitolisant as a portfolio and a product opportunity, and our goal is to optimize the Life Cycle Management Plan for pitolisant. As I mentioned earlier, my team and I are excited about this unique opportunity and focused on the three development programs that we will have up and running by the end of this year. I look forward to sharing our progress on these programs with you on future calls. Thank you, and I will now turn the call over to Susan Drexler, who will provide an update on our financial performance. Susan? Thank you, Jeff. I would like to join my colleagues in reiterating that we ended 2020 with a considerably strengthened financial position and are now poised to continue that momentum into 2021. Harmony demonstrated significant growth in commercial revenue for the full year of 2020 and reported sequential double-digit growth on a quarterly basis since commercial launch in November of 2019. Earlier today, we posted our fourth quarter and year-end press release and filed our 10-K, which contains the detailed operational and financial results for the year. I will just highlight a few key points. For the fourth quarter of 2020, Harmony reported $56.3 million of net product revenue and $159.7 million for the 2020 fiscal year. We are encouraged by the fact that five quarters into the launch, we continue to see an increase in the average number of patients and prescribers of WAKIX. This demonstrates that WAKIX offers a unique treatment option to address the unmet medical needs of adult patients with narcolepsy. Harmony's total operating expenses for the full year 2020 totaled $115 million versus $150.3 million in 2019. The decrease was primarily driven by a decrease in R&D expenses related to the payment of a $50 million milestone to Bioprojet, partially offset by an increase in sales and marketing and general administrative expenses related to the commercial launch of WAKIX. As of December 31st, 2020, bolstered by the $147.6 million in gross proceeds from our IPO, we had a cash and cash equivalent balance of $228.6 million. This compares favorably with the $24.5 million we had at the end of 2019. Of note, in early January of 2021, we remitted the $100 million milestone payment to Bioprojet, leaving us with a substantial cash position with which to continue our development programs and to help fund the potential acquisition of assets to expand our product portfolio. For the full year of 2020, Harmony posted a GAAP net loss of $36.9 million, or a loss of $2.48 per share. To the GAAP net loss of $36.9 million, we added interest expense of $28.2 million and depreciation and amortization of $10.2 million to arrive at a positive EBITDA of $1.5 million. EBITDA was impacted by several exclusionary items which were added to determine non-GAAP adjusted net income and included $22.6 million in loss on extinguishment of debt, $5.2 million of expense related to stock-based compensation, and $3.1 million of warrant expense. Therefore, our non-GAAP adjusted net income was $32.5 million. After deducting the $26.9 million of accumulation of yield on preferred stock, the adjusted net income available to common stockholders was $5.5 million or $0.21 per share. Looking ahead in 2021, we expect to make value-added investments in our core operating business, focused on the commercialization of WAKIX and the clinical support of pitolisant as we anticipate running three clinical trials. We expect strong year-over-year growth in sales with some normal quarter-to-quarter seasonality. In the first quarter, we will likely see the same payer-related dynamics that affect all specialty products early in the year. With a fortified balance sheet, growing revenues, and disciplined expense controls, we have the financial wherewithal to grow Harmony and deliver on the three pillars of growth detailed by my colleagues earlier in the call. I will conclude by saying Harmony is on a very solid financial footing and prepared to continue the momentum into 2021 and beyond. I would now like to turn the call back to John for closing remarks before opening the call up for the Q&A session. John? Thank you, Susan, and thank you to Dr. Dayno, Jeff Dierks, and Lisa Caperelli. I would like to take a brief minute to recognize and thank Susan Drexler for her service to Harmony and wish her the best of luck in her future endeavors. Our new CFO, Sandip Kapadia, will be formally joining us on Monday, and he's looking forward to meeting with all of you in the near future. The team and I cannot stress enough how remarkable of a year 2020 was for Harmony. I am proud of what we have achieved so far, confident in our ongoing success, and excited about what lies ahead in our future. Operator, we will now take questions from the audience. Our first question comes from the line of Chris Howerton from Jefferies. Your line is now open. Hi. Good morning, everybody. Thanks so much for taking the questions. Of course, congratulations on a great last year despite all the challenges. Thanks, Chris. Thank you, Chris. All right. I guess maybe just I can start off with a few questions and then, of course, hop back in the queue if any are remaining. For the first one, maybe just thinking about the expectations for this year from a spending perspective. I think, Susan, you gave a nice trends of what we could expect from the top line, but I guess a little more color on what we could expect on the spending side, particularly as it relates to SG&A. The second question, or maybe a couple questions might be for Dr. Dayno. With respect to the Prader-Willi syndrome trial, if you could maybe give us a little information with respect to the inclusion criteria for that trial, I think that would be helpful. It's striking to me that I think measuring EDS would probably be different in this patient population relative to narcolepsy. Maybe if you could just help us understand some of the accommodations you've made in terms of measuring some of the symptomology of the disease as it relates to the specifics of this patient population. Thank you. Thank you, Chris. Just to answer the first two questions you have about sales and marketing and G&A, you're correct, we haven't provided guidance. For sales and marketing in particular, we do expect that expense to increase as COVID lifts and our team begins to engage in person with physicians in the future. Obviously, we'll see that trend unfold as 2021 continues. On the G&A side, we do expect those expenses to increase as well due to the fact that we're a public company, and there's also going to be an impact as COVID lifts on that expense as well. Okay, great. Okay. Dr. Dayno, you want to take the next question? Thanks, Chris. In terms of the inclusion for the PWS trial, the main inclusion is a minimal amount of Excessive Daytime Sleepiness. Let me start off by saying the reasons for Excessive Daytime Sleepiness in patients with Prader-Willi is multifactorial. There are similarities in that patient population. There's some overlap with narcolepsy in terms of sleep-wake state stability and the primary underlying disorder centered in the hypothalamus. The main inclusion criteria is a minimal amount of Excessive Daytime Sleepiness as measured by the Multiple Sleep Latency Test or the MSLT. That's the main inclusion criteria along with the age range and other aspects with regards to managing sort of the safety component of the product. It's similar in terms of EDS measuring in clinical trials with both the objective endpoint as well as subjective endpoints looking at Excessive Daytime Sleepiness. As I mentioned, in addition, we're also looking at key secondary outcomes around behavioral symptoms as well as cognitive function. Okay, excellent. Maybe just as a very quick follow-up to that, could you give us any maybe color on your thinking with respect to doses? I think you said a low and a high dose. Maybe if you could just frame that a little bit for us. Sure, Chris. Yes. The dosing strategy we're looking at based on the pharmacokinetic profile pitolisant and some of our dose modeling. We're looking at doses consistent with current doses in the label, as applied to the three different age groups within the trial. As I mentioned, we're studying patients ages 6- 65, which is a fairly broad range. Children ages 6- 11, then we have adolescents 12 to less than 18, and then the adult part of that cohort. We have a low dose and a high dose sort of applicable to each of those age groups based off of our PK modeling. I see. Okay, got it. Okay. All right, that's clear. Okay. Well, thanks for taking the questions. Appreciate it. Yeah. Thanks, Chris. Thank you. Our next question comes from the line of David Amsellem from Piper Sandler. Your line is now open. Hey, thanks. Just a few. First, regarding pandemic related headwinds, one of the things that you talked about last year is paying the full cost of drug for patients, and that was having an impact in the third quarter. Can you talk about the extent to which that had an impact in the fourth quarter and how we should think about the impact of that dynamic in 2021? That's number one. Number two is, with the label expansion in cataplexy, can you talk about the mix between narcolepsy Type 1 and narcolepsy Type 2 these days, and how you think that's going to evolve as the year progresses? Thirdly, as far as an easing of pandemic related headwinds, what are your thoughts regarding when we should be getting to sort of a normalization of in-office visits and ultimately how we should think about that in terms of cadence of sales? Do you expect, say, second half of this year that we'll get sort of an uptick in sales and volumes as we see this normalization play out? Help us understand that a little bit better. Thank you. Jeff Dierks, you want to take that first question? Sure. No, thanks very much, David Amsellem. I appreciate the question. With respect to pandemic related headwinds and the free goods impact, as we've shared in our prepared comments as well as in our last earnings call, since the beginning of the pandemic, we have seen a rise in unemployment and obviously the subsequent loss of health insurance for millions of Americans. As a result of that, we have seen an increased demand in our Patient Assistance Program. It's been relatively consistent, even into Q1 of this year. We certainly have a strong conviction to make sure we can support eligible patients through this program, knowing the difference that WAKIX can make in patients' lives. I think looking forward, it's really difficult to speculate how long this elevated demand for our Patient Assistance Program will continue. What I will be able to say is obviously we've been able to demonstrate a 20%+ growth in net revenue each quarter, even with this elevated demand. I think we're really excited for 2021 and the difference we can continue to make for patients living with narcolepsy. Jeff, I think, David, does that answer your question there before we move on? Yeah, that's helpful. Thanks. Jeff, I think the next question was for David. It would apply to you as well. Cataplexy, the mix of Type 1 and 2 and the type of reaction we've been hearing from the market. Perhaps after you, Dr. Dayno could add some color from the medical community on that as well. Sure. With respect to cataplexy, obviously, we're very pleased with the early positive signs that we are seeing since the label expansion. We know and have communicated that securing the additional indication for cataplexy was certainly a key element to add to the overall benefit risk profile of WAKIX to support continued growth of the product. Now, we haven't provided specific guidance on what sales are being driven by cataplexy, but what I can say is that we have seen an increase in the percentage and the volume of prescription requests for narcolepsy patients with cataplexy. We know that the literature suggests that up to 2/3, that 70% of people living with narcolepsy may have cataplexy. Clinically, we're seeing about a 50/50 mix in Type 1 and Type 2 patients being diagnosed and treated. David, what I would say is that our business looks to mirror that relatively close. The other exciting news that we've seen is, in addition, some of the managed care plans have already started to make some positive formulary policy changes, reducing or eliminating generic step edits for Type 1 patients, which really allows the acceleration of patients' ability to get access to WAKIX. I think across the board, we're very excited about the early signs that we've seen. It speaks volumes, I think, to our future ability to continue to make a difference for adult patients living with EDS or cataplexy. Yeah. Thank you, Jeff. And David. Hi, David. It's Jeff Dayno. I would just add from a medical perspective, I think, the cataplexy indication, I think it just reinforces in the minds of healthcare professionals. I think it reinforces the data that was in the literature with regards to the HARMONY CTP trial and reduction in cataplexy that a lot of the sleep docs have been familiar with. What we've heard is that it just kind of validates the data that they were familiar with. It strengthened the product profile. With regards to the clinical decision-making, obviously, some HCP is more comfortable when you have the indication. Those are some of the things that we've heard from the physician community and consistent with the trends that Jeff Dierks alluded to. Thank you, Jeff. David, I believe your third question had to do with sales volumes and the headwinds of COVID and predicting when we might hit some stabilization there. Jeffrey Dierks, you had some comments to make there. Yes, certainly. David, for your third question, I think it's very hard to sort of speculate when, quote-unquote, COVID's going to lift and we'll get back to that normalization. Certainly what I can say is we have not hit our normalization for WAKIX. We know that there are 72,000 diagnosed and eligible patients living with narcolepsy that really represents the near-term opportunity for us, and I think we've barely scratched the surface in our ability to really help those patients with having about 2,500 average number of patients on Q4. We're extremely optimistic about our opportunity because you certainly know that there is a significant unmet medical need in this marketplace. The unique product profile of WAKIX very clearly aligns to that unmet need. Once this pandemic lifts and patients have the ability to see their healthcare professional, our field sales team has the ability to engage and educate the community. We know that these individuals are going to be living with a lifelong chronic neurologic disorder, that narcolepsy will still be there after COVID, and we're extremely optimistic about what 2021 looks like and beyond. Can I just sneak in a follow-up? In terms of the free goods and just the sales cadence, and also the reimbursement landscape, with all the comments that you made, what does this imply in terms of gross to nets and particularly gross to nets moderating as the year progresses? It's Susan. For gross to nets, as we've expressed previously, we're not sharing the gross to nets for competitive reasons. That's not something we're sharing at this time. David, maybe what I can add with respect to just the commercial insight is, one of the things we shared in our prepared remarks is that we're anticipating that we're going to face those same payer-related dynamics that we saw in 2020 in the first quarter that affect all branded and specialty products, right? Those dynamics, as you're well aware, you've got insurance reauthorizations that occur for many prescriptions that require patients to get reapproved for continuing their medicines. You've got the reset to all the co-insurance and the Medicare deductibles, which obviously requires patients to lean on manufacturers for support predominantly in the first quarter. Then obviously there are some increases to co-pays for a subset of commercial patients as formularies are being changed each year. As Susan said, we're not providing guidance related to the net revenues or our gross to net. What I can say is we expect strong year-over-year sales growth, right? We continue to expect to grow the average number of patients each quarter, but we are going to be expecting some normal quarter-over-quarter seasonality in Q1. I think that that really speaks to not only the market opportunity, but really the receptivity that we've seen from the physician and the patient community about the overall benefit risk of WAKIX. David, as the COVID pandemic lightens and we start vaccinating our population and getting back to more of a normal rhythm in life that all of us are hoping for in our society and our businesses, we do expect some of the pressure on that Patient Assistance Program to lift because it tends to track with the unemployment rate and what we're facing in the U.S. If that gets better, we expect that cost to go down for us. Okay. Great. Thanks. Thank you, David. Thanks, David. Thank you. Our next question comes from the line of Graig Suvannavejh from Goldman Sachs. Your line is now open. Hey, good morning, everyone. Thanks for taking my question and congrats on the quarter. I want to thank you, Susan, for all of your help and good luck in your next endeavors. Maybe a couple of questions, if I could, just one. Is it possible to get any additional color on TRx or NRX trends, particularly what you saw in 4Q versus 3Q, and maybe any comments you can make about what you're seeing year-to-date versus 4Q particularly on the NRX side? That would be my first question. My second question just has to do with the sales growth that you saw in the fourth quarter. Is it possible to tease out how much of that growth was specifically tied to price versus volume growth? Then my last question just has to do with if you could provide any additional color on what you're seeing in terms of adherence or compliance right now with WAKIX. Thanks. Jeff Dierks, you want to handle the question from Graig? Yeah. I'll take them kind of in order as you shared. With respect to just a little bit of color on demand and new patients, what I would say, Graig, is that we're extremely pleased with obviously the launch performance in Q4. We saw a 15% increase in the average number of patients quarter-over-quarter, and that, along with strong refill behavior, led to another quarter of net revenue growth of 20%. Solid growth in average number of patients, it was in line with our expectations given COVID. We fully anticipate that we're going to continue to grow the average number of patients of WAKIX through each quarter, 2021 and beyond. I think the average number of patients really not only reflects the increase in the number of new patients, but also speaks to the durability of the compliance and persistency of the existing patients. We're not providing specific guidance on new versus continuing patients, but the average number of patients represents both of those cohorts. What you've seen is a 15% increase, which is a really solid growth and in line with our expectations for Q4. Second question you asked with respect to Q4 sales growth and what was driven by demand versus price. Q4 net sales were $56.3 million. That represents a 23.4% increase from the third quarter. Demand or volume represents about 19% of that growth, with the remaining less than 5% driven by the price increase taken in November following the approval of the cataplexy indication. I think importantly for us is we believe that that demand growth demonstrates the unmet medical need that exists in the marketplace and how well the differentiated product profile of WAKIX is being received by the narcolepsy community. Third, you asked a little bit about some color on adherence and compliance. We talked a little bit about the average number of patients being 2,500, and that obviously speaks to the durability of patient persistence and compliance. It's still early in our launch. Although we're not sharing specific information about discontinuation rate compliance persistence, what I can say is that what we're seeing with the WAKIX patient medication behavior observed to date is consistent with what's been seen with the other oral narcolepsy products. Right? It demonstrates that the overall benefit risk profile is being received very well, and that's kind of really being reinforced by the feedback that we're hearing from the narcolepsy physician and patient community. Hopefully that helps to respond to your questions, Graig. Thank you, Jeff. Thank you.