Good morning. My name is Rob, and I will be your conference operator today. I would like to welcome everyone to the call. At this time, all lines have been placed on mute to prevent any background noise. After the speaker's remarks, there will be a question-and-answer session. Thank you. I'd now like to introduce Beth DelGiacco, Vice President, Corporate Communications and Investor Relations. You may now begin your conference. Thank you. A press release was issued earlier today with our first quarter 2025 financial results and business updates. This can be found on our website along with the presentation for today's webcast. Before we begin on slide two, I'd like to remind you that forward-looking statements may be presented during this call. These may include statements about our future expectations, clinical developments, regulatory timelines, the potential success of our product candidates, financial projections, and upcoming milestones. Actual results may differ materially from those indicated by these statements. argenx is not under any obligation to update statements regarding the future or to conform these statements in relation to actual results unless required by law. I'm joined on the call today by Tim Van Hauwermeiren, Chief Executive Officer, Karl Gubitz, Chief Financial Officer, and Karen Massey, Chief Operating Officer. I'll now turn the call over to Tim. Thank you, Beth, and welcome, everyone. I'll begin on slide number three. At Argenx, we are building our company for the long run. Our strategic decision-making, paired with an agile approach, has positioned us to deliver sustained growth in a dynamic and evolving market landscape. It's with this same long-term focus that we introduced an ambitious Vision 2030 to reach 50,000 patients across 10 labeled indications and advance five phase three assets. This quarter, we continue to execute against a bold innovation agenda, keeping us firmly on track to realize this vision. We successfully launched a pre-filled syringe in the U.S. and Germany to reach more patients with VYVGART. We are advancing 10 registrational and 10 proof-of-concept studies across our pipeline, and we remain on track to progress four INDs in the clinic this year, with ARGX-109 and ARGX-213 now in phase one studies. Slide four. Our focus on execution continues to yield results. Let's begin with our commercial business, where underlying growth is exactly where we expect it to be. Consistent with last year, first-quarter results reflected typical seasonality following an exceptional fourth quarter. Karen will share more details on launch dynamics later in the call, but big picture, key physician and patient metrics across both gMG and CIDP continue to be strong. Looking at the full year ahead, we remain confident in our ability to drive consistent growth. First, we were thrilled to receive an optimal label in the United States, with the recent FDA approval of VYVGART Hytrulo pre-filled syringe for self-injection. This comes at a perfect time to maintain our growth momentum and broaden our patient reach in gMG and CIDP. We are excited with the opportunity ahead for CIDP and have just launched our patient activation campaign. This will be critical to empower CIDP patients in their decision-making to choose the best therapy for them. We continue to see a demand for innovation in the gMG and CIDP market. We are building the broadest offering possible to support this unmet need. This includes advancing our auto injectors and progressing our label expansion studies in seronegative and ocular MG. Finally, we recognize that the global market is dynamic at the moment. While it is still too early to speculate how our industry will be impacted by future policy developments, we are confident that our strategic decisions to date have positioned argenx to navigate a range of potential outcomes. We are prepared to meet growing demand for our precision therapies with a robust global supply chain and a strategy to manufacture in each region for that region. This includes continued and long-standing investment in our U.S. manufacturing capabilities to ensure long-term scalability. Slide five. Taking a step back, the success of our commercial efforts is rooted in patient and physician demand for new and innovative treatment solutions. Last month at AAN, we had the opportunity to present data that reinforced the broader potential of VYVGART and reflect our commitment to generating data that is most meaningful to the neurologist community and the patients they serve. VYVGART continues to set a high bar with its sustained efficacy and improved quality of life measures for patients living with gMG and CIDP. Beginning with gMG, more and more neurologists are recognizing Minimal Symptom Expression, or MSE, as the metric most relevant to patients. New data from the ADAPT-NXT study showed that 56.5% of patients achieved MSE at any point during treatment. We believe that an individualized treatment approach is the best way to treat gMG, given that each patient experiences the disease differently. The ADAPT-NXT study supports this view, showing that both fixed and biweekly dosing regimens can deliver rapid, meaningful, and sustained improvements for up to 126 weeks. Recognizing that we're still early in the launch of VYVGART Hytrulo in CIDP, we were encouraged by our engagement with treating physicians and some of the positive patient experiences they've already seen. We shared new open label data, showing that Hytrulo can drive sustained functional improvement, and highlighted our switch study design, which looks at patients switching to Hytrulo within one week of the last IVIG treatment. Finally, VYVGART's strong and predictable safety profile remains a critical part of its value to patients and physicians. We have over 8,000 patient years of data across studies and are proud to have a label with no vaccinations, no ramps, no black box, and no monitoring. Delivering on our Vision 2030 will also depend on the progress of our pipeline, and I'm particularly energized by the breadth of indications we're pursuing across multiple first-in-class assets that open the door to new disease areas with high unmet needs. We continue to push the boundaries of our understanding of FcRn as we explore new therapeutic areas with efgartigimod, including rheumatology with myositis and Sjögren's and endocrinology with TED. These are high-prevalence diseases where we see a clear path to deliver meaningful, differentiated benefits to patients. With empasiprubart, we have taken a bold approach, advancing our C2 inhibitors into two registrational head-to-head studies against IVIG in both MMN and CIDP. These trials reflect our commitment to disrupting the treatment paradigm for each of these diseases by challenging the standard of care and bringing forward innovation for patients in need of new precision treatment options. Finally, let's take a look at what's ahead for the rest of the year with several readouts across the pipeline. The seronegative gMG study will be the first of our 10 registrational trial readouts, which has the potential to expand the breadth of gMG patients we treat. Beyond that, we have proof-of-concept readouts in lupus nephritis with efgartigimod, delayed graft function with empasiprubart, and CMS with ARGX-119, the first clinical readout for our third asset. We have two primary objectives with our proof-of-concept studies. First, to gain confidence in the signal observed to invest in further development, and second, to thoughtfully shape the phase III design. Before turning the call over to Karl, I want to circle back to our innovation mission. We have always put innovation at the forefront of our decision-making, which means prioritizing what patients need and ensuring that we remain forward-thinking to prepare ourselves for the long term. With an enviable financial position, we're able to continue investing in our innovation engine, capitalizing on both commercial and clinical opportunities to deliver sustained long-term value, and with that, I will turn the call over to Karl. Thank you, Tim. The first quarter 2025 financial results are detailed in this morning's press release. Total operating income in the first quarter totals $807 million. This reflects $790 million in product net sales and $17 million in other operating income. The product net sales of $790 million represents 99% growth compared to our corresponding prior year quarter. The product net sales break down by region to $681 million in the U.S., $32 million in Japan, $57 million in the rest of the world, and $20 million for product supply to Zai Lab in China. On a quarter-over-quarter basis, comparing Q1 2025 with Q4 2024, the growth is 7%, with the U.S. growing at 5%. We saw strong underlying demand in both gMG and CIDP, with growth in net sales impacted by two factors. First, typical Q1 seasonality with re-verification of benefits for patients. And second, Medicare redesign took effect on January 1, which accelerated the evolution of the channel mix to Part D. This had an impact on gross-to-net for the quarter. We expect PFS self-injection to further drive a shift to Part D, though over time, the impact on revenues from increased gross-to-net will be offset by patient volume growth, specifically our ability to reach new patient populations with PFS for self-injection. In Japan and the rest of the world, the quarter-over-quarter growth continues to be in the high teens. Next slide. Cost of sales is $81 million in Q1. This reflects a gross margin of 90%, which is in line with previous quarters. Total operating expenses in Q1 2025 are $668 million, a quarter-over-quarter growth of 2%. The increase is explained by a $12 million increase in R&D, offset by a decrease of $10 million in SG&A. This results in operating profit for Q1 of $139 million. The quarterly net financial income is $36 million. We benefit in the quarter from unrealized exchange gains of $27 million on our non-U.S. denominated cash balances. The effective tax rate for Q1 2025 is 16%. After tax, the profit for the quarter is $169 million. Our cash balance, represented by cash, cash equivalents, and current financial assets, is $3.6 billion at quarter end, an increase of $238 million from Q4 2024, driven primarily by cash flow from operations. Our previously issued guidance on total R&D and SG&A for the year remains unchanged. I will now hand it over to Karen. Thank you, Karl. Slide nine. Our patient-centric approach to innovation continues to deliver real-world results, as we have now successfully brought a first-in-class medicine to patients across multiple markets, executing launches across three indications, three product presentations in over 30 countries in less than four years. With this launch cadence, we have maintained steady momentum and delivered 13 quarters of growth. This is a remarkable achievement, and I'm incredibly proud of the entire argenx team for the focus, dedication, and the collaboration that has made it possible. We continue to drive meaningful impact with VYVGART, expanding our reach to new patients and prescribers in both CIDP and MG, as well as ITP in Japan. With the recent approval of our pre-filled syringe, which further enhances patient access and convenience, we expect that momentum to continue. Today, I'll walk you through the dynamics behind our performance this quarter and how we're positioned to continue to drive sustained long-term growth and deliver lasting outcomes for patients. Slide 10. We're continuing to deliver on our long-term growth strategy with 99% year-over-year revenue growth for the quarter and steady growth delivered across every region and indication. After an incredibly strong fourth quarter, we face typical first-quarter seasonality in the U.S., which, similar to last year, is primarily due to benefit re-verification. This quarter also marked the first industry-wide impact of Medicare Part D reform, which is accelerating the evolution of our channel mix towards Part D. As Karl outlined, due to this dynamic, we saw an impact on our gross-to-net over the quarter. Looking beyond these technical impacts in the U.S., we saw a strong quarter, and we continue to deliver consistent growth. I am very pleased with our performance in new patient starts, in new prescribers, and in high patient conversion rates. We believe there is significant commercial opportunity ahead of us for both gMG and CIDP. In gMG, VYVGART achieved the fastest market share growth amongst branded biologics, solidifying the number one position in the MG market. VYVGART Hytrulo is the key growth driver, contributing to a strong quarter-over-quarter increase in new patient initiations. In CIDP, our strong launch momentum continues with consistent quarter-over-quarter growth in new patient starts. Although we recognize the CIDP market dynamics are unique from MG, early trends reinforce our confidence in the significant long-term opportunity for VYVGART Hytrulo in this market. In addition to strong patient starts in both MG and CIDP, we continue to see consistent new prescriber growth. Over the quarter, we added about 250 first-time VYVGART prescribers, bringing us to over 3,700 total prescribers. We saw a reciprocal halo effect between MG and CIDP. Reaching new prescribers is a critical priority to increase the breadth and depth of patients that we reach. We also saw a solid performance internationally. Japan's CIDP launch is off to an encouraging start, echoing the US experience, with patients and prescribers welcoming the first novel mechanism for CIDP treatment in 30 years. The contribution from the rest of the world continues to grow as we secure pricing and reimbursement agreements across Europe and Canada. In Europe, VYVGART subcutaneous continues to expand our gMG uptake, including initial pre-filled syringe use in Germany. Lastly, we're close to bringing VYVGART to its second indication in the EU, with positive CHMP opinion last month in CIDP. Slide 11. The recent approval of our pre-filled syringe for self-injection in the U.S. comes at the perfect time to enable our continued growth momentum in MG and CIDP. The label we received is an optimal outcome. Patients now have the ability to self-inject in as little as 20 to 30 seconds after being trained with proper instruction, and they can do so at home or in the HCP office. Patients will have the flexibility and independence to manage their treatment in a way that fits their lifestyle and continue to benefit from VYVGART Hytrulo's strong efficacy and favorable safety profile. The first patients have already been dosed with PFS for self-injection in the U.S. and Germany. Reception to date has been very positive, with encouraging initial patient prescriptions. You'll recall we are not pursuing a conversion strategy with PFS for self-injection. Rather, our goal is to reach more patients earlier in the treatment paradigm. We're seeing that play out already, with 50% of initial enrollments first-time VYVGART users. Patients have been vocal in their positive feedback, often referencing the PFS as game-changing. One patient commented that he was now ready to take back control of his life and eager to travel with his family. Another patient shared her relief to be able to manage her work schedule instead of taking off significant time for weekly infusions. We're just at the beginning of this launch, and we've continued market expansion in the U.S. and future expansion opportunities in Canada, China, and Japan. Slide 12. We're transforming the MG and CIDP treatment paradigm with VYVGART and VYVGART Hytrulo, and we're empowering patients to expect more from their treatments. This is especially true for CIDP patients who have not seen new novel mechanisms of action in the space for close to 30 years. Physicians are more conservative in switching their CIDP patients between medications in general and often prefer an active request from the patient before doing so. In February, we successfully launched our patient activation campaign, which is empowering patients to ask their neurologist about VYVGART Hytrulo. We are seeing a very high grant rate to these requests, demonstrating that neurologists believe in the value proposition of VYVGART Hytrulo for CIDP. Our patient engagement efforts across both gMG and CIDP led to a significant increase in patients actively requesting VYVGART or VYVGART Hytrulo over the quarter. Slide 13. What excites me most is the tremendous opportunity ahead to expand the impact of our precision medicines. We are exactly where we need to be if the right strategy is in place to reach patients earlier in their treatment journey. We've successfully launched our pre-filled syringe, and we're generating the data needed to position VYVGART as the treatment of choice in both MG and CIDP. And this is just the beginning. With multiple potential launches ahead, we're ready to expand into new high unmet need indications, bringing our therapy to thousands more patients and advancing our vision to redefine the standard of care in autoimmunity. With that, I'll turn the call back to Tim. Thank you, Karen. We have an incredibly strong foundation to deliver significant growth this year and beyond, which puts us perfectly on track to achieve our Vision 2030. We have the benefit of a strong financial position to continue investing in our commercial business and early innovation. With multiple expansion opportunities ahead, we plan to sustain our growth trajectory in MG and CIDP. Additionally, we have a steady cadence of several milestones across a robust pipeline, which will further contribute to patient growth and support our leadership in autoimmunity. Execution has always been a key strength of our company, and therefore we enter the remainder of the year confident in our ability to deliver value to our patients and shareholders, whose long-term support has been critical to our success. We will now open the call for questions. Thank you. We will now begin the question-and-answer session. If you'd like to ask a question, please press * 1 in your telephone keypad to raise your hand and join the queue. If you would like to withdraw your question, simply press * 1 again. We ask that you please limit yourself to one question only. Your first question comes from the line of Tazeen Ahmad from Bank of America. Your line is open. Hi, guys. Thanks for taking my question. I wanted to ask a more broad one on the profile of the gMG patients at this stage of the launch that are starting VYVGART therapy. So can you just tell me what portion of the curve you're on in terms of onboarding the patients that are out there that are not currently receiving therapy? And then also, are you noticing any changes in discontinuation rates and any impact from competing products so far? Thanks. Thanks for the question, Tazeen. Appreciate it. And as you say, I mean, where I come from, we're 13 quarters into the launch for MG, and I'm really proud of the fact that we've continued to deliver growth quarter over quarter, despite a very high quarter last in Q4. And I think what that indicates is that we're still early in the launch curve for MG. What we see in terms of the patient profile, to your specific question, we still see about 60% of patients coming to VYVGART from orals. So it shows that we're still moving into earlier lines of treatment, which is exactly the strategy that we're pursuing as we expand the market. And what we're seeing is the market for biologics is growing, and VYVGART is leading that growth. We maintain the number one market share amongst biologics in MG. So we're expanding our leadership, and pre-filled syringe and the launch of pre-filled syringe is only going to accelerate this as we continue in the launch. So I would say we're at the early phase or early stages of the launch curve at this point. Thanks for the question. Sure. Next question comes from a line of James Gordon from J.P. Morgan. Your line is open. James, your line is open. Hello. James Gordon, J.P. Morgan. Thanks for taking the questions. Hello. Can you hear me? This is James here. Can you hear me? Yes, we can hear you. Yes, we can hear you, James. Hello. Can you hear me okay? Yes, James. We can hear you. Testing whether you can hear me. We are experiencing some technical difficulties with that line. We're going to move on to the next question from Alex from, sorry, Alex Thompson from Stifel. Your line is open. Hey, great. Congrats on the quarter, and thanks for taking our question. I guess as we think about the PFS launch now with three VYVGART forms on the market, can you talk about how we should think about net price over time? Thanks. Yeah. Thanks. Happy to talk about the PFS launch. Maybe I'll just start by saying that we're really pleased with the label that we received as part of the approval. And I want to share a huge congratulations to the team. We did get the optimal label. And what we're seeing already is positive feedback from the PFS launch from both prescribers and from patients saying that it's a game changer. So we think that this will be an expansion opportunity and that it will drive growth, continue growth for VYVGART through the year. But maybe Karl, you want to comment on the gross-to-net? Yeah. Thank you, Alex. PFS will, of course, be pharmacy benefit, and the gross-to-net will have a different dynamic in the pharmacy benefit versus the medical benefit due to the 20% manufacturers have to pay for patients in the catastrophic phase. Therefore, the net price per patient for PFS patients will be lower than for patients in the medical benefit, which will largely be IV and VYVGART Hytrulo. At the moment, we will maintain the $225,000 for an MG patient and the $454,000 CIDP patient, but over time, that will evolve, and we can give you updates later on. Yeah. Do you want to also just answer the discontinuation question from the last? Yes, Tazeen. Sorry, I think you asked about discontinuations as well. And so just to come back to that, we're not seeing any shift in discontinuation. In fact, we see the consistent discontinuation rates, and I would say, given that it's a maintenance therapy and a chronic treatment, it's quite strong. And you can see that the patients are definitely appreciating staying in MSE and the adverse event profile. So no shift in discontinuation rates for MG. Your next question comes from Vikram Purohit from Morgan Stanley. Your line is open. Hi, great. Good morning. Thanks for taking our question. Ours is on CIDP. If you could just help us understand in a bit more detail the cadence of new patient starts, where you ended Q1 with in terms of patients on therapy and how you might expect that to trend throughout the course of the year. Thank you. Yeah. Thanks for the question on the CIDP launch. I would say we're really excited about where we are with the CIDP launch. What we've seen is continued momentum since the beginning of launch and through Q1. The execution continues to be strong. When you look at the underlying fundamentals to your question, what we see is continued new patient adds quarter over quarter. We also continue to see new prescriber growth quarter over quarter, which is a really important measure to demonstrate that we're reaching more prescribers and therefore reaching more patients. And the other really important feedback that we have from this quarter is the consistent patient stories that we're hearing about the transformational impact that VYVGART is having on their CIDP. So, I mean, patients are at the center of our launch and are key to the CIDP launch. We launched our DTC campaign in Q2. And what we're seeing is that more and more patients are initiating the request to switch with their prescribers. And in the majority of cases, their neurologists are granting that switch request. And what that shows us is that neurologists believe in the profile of VYVGART for CIDP. So all of the underlying launch metrics for CIDP continue to be very strong. Your next question comes from Rajan Sharma from Goldman Sachs. Your line is open. Hi. Thanks for taking the question. Just to follow up on the Q1 effects, you mentioned that there were two factors that you kind of talked to as being headwinds to revenue growth for the quarter. So that was a re-verification and then the Medicare redesign impact. Could I just push you a little bit on relative magnitude of each of those and which was the larger impact in Q1? Thank you. Rajan, thank you for the question. Let me talk about the gross-to-net impact. In prior quarters, we've seen a gradual increase quarter over quarter of Part D. At the close of Q4 2024, it was a minority, a small portion of patients. At the last earnings call, we discussed that in 2025, with the launch of PFS self-injections, patients under the pharmacy benefit, which is Medicare Part D, will grow. And as that mix evolves between medical and pharmacy, the gross-to-net will increase. What we've seen now in Q1 is, with the Medicare redesign, is an acceleration of patients choosing to receive Hytrulo at home even before PFS. This underscores the need we will be filling with PFS self-injection as it will expand the market. In terms of the magnitude of the gross-to-net, we can't get into more detail now. We will provide probably more detail at the end of Q2, but you did see an increase in gross-to-net. But the majority of the impact you're referring to is to do with the seasonality relating to the re-verification of benefits. That is an industry impact which you always see. Maybe Karen, you want to talk about that? Yeah. Thanks, Karl. I think that's really clear. And I think that's important to note. What we saw in Q1 is similar to what we saw in Q1 last year and the normal industry dynamics of seasonality related to benefit re-verifications and impacting the volume. But remember, VYVGART is a growth story. We saw growth in Q1. We had the PFS approval in Q1. And what we expect to see is continued growth and continued cadence of growth through the remainder of the year as we continue to launch PFS for both MG and CIDP. Your next question comes from a line of James Gordon from JP Morgan. Your line is open. Hello. Thanks, James, again. Thanks for taking the question and for bearing with me for any technical issues here. If the question was Most Favored Nation is coming to focus again, and there were some concerns around different list prices for VYVGART in different places. So can you remind me how VYVGART's list price varies between the U.S., E.U., and Japan? And also, have you already set the PFS price outside the U.S.? So how the list price varies there? And if I could also just ask a follow-up question. So as has been discussed, some impact this quarter from patients shifting to Part D, and that comes in with a catastrophic discount from the company. But looking to Q2 and the rest of the year, are you seeing significant further incremental headwinds from this Part D shift and then falling net price that we need to be wary of when we're thinking about Q2 and the rest of the year? Or is one way of thinking about it looking like the phasing we saw last year in 2024, where Q1 was a bit softer sequentially, but then Q2 saw quite an acceleration because you didn't have the recertification headwind, and then you've got PFS coming in, and you've got more CIDP coming in. So should we look at last year's phasing for a bit of a guide for what this year's phasing looks like? Okay. Thank you, James. I think you asked three questions, so let me take them one by one. First one is on most favored nations. We have been very disciplined and aim to keep the list price in all our markets within a narrow band. For example, with the launch of VYVGART in Germany, the list price was set very close to the U.S. list price. Prices evolve, of course, over time due to foreign exchange, label expansion, and so forth. But that said, we've done a good job in keeping the list prices in all our priority markets in a narrow band. On your second question, the PFS pricing has been set in all our priority markets. So I think that's done. Your third question, I think in terms of Q2, I think it goes back to what Karen has said, that PFS is an expansion strategy which will give us more prescribers and more patients. But yes, gross-to-net will also increase quarter over quarter as the product mix between medical and pharmacy changes. Yeah. And I'm just going to add, in terms of the rebound effect that you mentioned, I wouldn't think about it like that. I would zoom out. And what you can see when you look quarter over quarter since the beginning of the launch of VYVGART, when you take a line through it, it's relatively consistent growth quarter over quarter. So we don't look at the ups and downs each quarter, but rather I'd encourage you to take that line through it and look at the long-term trajectory. And we're confident that that consistent growth will continue over the long term. Your next question comes from a line of Derek Archila from Wells Fargo. Your line is open. Hey, good morning, and thanks for taking the questions. Just wanted to see, given the ADAPT-NXT publication and the dataset there, are you assuming increasing number of treatment cycles in MG patients as part of your growth calculation to offset the Part D exposure? Thanks. Thanks, Derek. Thanks for the question. If you look at the material consumption between ADAPT-NXT or cyclical dosing, actually, net you end up using the same amount of material. So we do not believe this is going to materially impact the dosing of VYVGART. I think what is really important about ADAPT-NXT is that now we have taken the individualization to the end. Now, each patient can dose the drug the way it should be dosed from cyclical to continuous dosing. So now we can offer the full spectrum. We're very proud of the data. At AAN, I think we showed impressive efficacy data from ADAPT-NXT with a 56% MSE, spick-and-span safety profile, and a real nice continuation over 126 weeks of use. Thank you for the question. Your next question comes from a line of Yaron Werber from TD Cowen. Your line is open. All right. Thanks so much. Maybe, Karen, just a question for you on CIDP. Is there any chance you can give us a little bit of a sense how many patients did you have during the quarter or finish during the quarter? And then sort of related to that, at AAN, there was a publication, right, that looked at safety in CIDP, and you had just over 1,300. I think it was 1,316 real-world patients on VYVGART at that point. Can you triangulate that maybe to, again, your commercial patient numbers on CIDP? Thank you. Yeah. Thank you for the question. We're not updating that number at this moment. What we'll do in the style of what we've done for other launches is update the number as we hit different milestones. But what I would say, again, just zooming out, is we have had consistent patient adds quarter over quarter and consistent prescriber growth in CIDP. We've also seen consistency in where the patients are coming from. And what I mean by that is 85%-90% of the patients continue to be switched from IVIG or subcutaneous IG to VYVGART. And that's exactly in line with where we thought we would be at this moment in launch and with the 12,000 TAM. So we think we have a long way to go in terms of our growth. We're just at the start of the growth trajectory with the CIDP launch. Certainly, PFS will be a strong driver of that continued expansion as we continue to launch PFS through the year. Thanks for the question. Your next question comes from a line of Victor Floc'h from BNP Paribas. Your line is open. Very quick. Thanks so much for taking my question, Victor Floc'h from BNP Paribas. So I was just, I mean, obviously, there has been a lot of focus on the price implication of the PFS ramp-up as a Part D product. But at the same time, I think it would be helpful if you could share with us your expectation in terms of incremental volume attached to the PFS opportunity. I mean, I think you've notably said that you were basically not following a conversion strategy. So, I mean, you are looking at add patients. So, I mean, I think we tend to look at the price right now. We tend to look at the implication on the price. But, I mean, what are your expectations in terms of volume growth tied to the PFS? And my follow-up is very much close to the first one. It's about the seronegative phase III trial. I mean, a lot of, I mean, investors have been pointing pretty light news flow for the next part of the year. I mean, there is the phase III in seronegative, and maybe for some of them, it's seen as a given. But, I mean, it would be nice if you could share also your view on the opportunity in terms of incremental volume and potentially sales there because, obviously, it's not nothing to grow the addressable opportunity from 80% to 100% of patients, even though I agree that, I mean, it's fair to say that the risk is pretty low. But yeah, any comment on volume would be super helpful. Thanks so much. Yeah. Thanks for the question. I'll take the first one. I think Tim will take the second. So I would say we're confident about PFS driving significant volume growth both for MG and CIDP. I would say we got the optimal label, and I would like to say huge congratulations to the team. I mean, when you look at 20-second- 30-second injection time, no specific monitoring or training requirements. These are all features, but the benefit that we see and that we hear from patients are that they are completely free from the office. We hear that they're excited. You heard in the script that patients are describing this as a game changer in terms of managing their MG and CIDP. So, as you said, this is a market expansion opportunity for us. What we're seeing in the early data is that 50% of the PFS prescriptions are new to VYVGART patients. So they're not converted. Rather, they're overall new to VYVGART, and that's exactly in line with this market expansion strategy. So if you zoom out, what we're looking to do in both MG and CIDP is bring new innovation and patient-centric innovation to the market. And we're seeing this exactly in PFS. And that's what's going to drive the long-term growth trajectory for both of those indications. And then maybe for the seronegative and the news flow, Tim, do you want to take that? Yeah. I think, Victor, you're right calling out the news flow for this year, which I think is strong with one phase III readout and three phase II readouts. This company is in a strong position from a news flow point of view. So the phase III readout in seronegative myasthenia, the phase II in lupus nephritis for efgartigimod, the phase II in delayed graft function for empasiprubart, and then the phase II proof of concept in CMS for 119. Specifically on seronegative MG, I think we are very excited about the opportunity in front of us. You have to think about 15% of the overall MG patient population, which falls in the seronegative basket. We do know from Japan that we have seronegatives on label that VYVGART is offering the same benefit risk profile to seronegative patients as it does to the acetylcholine receptor antibody patients. So very strong performance. Now, it's all about the design of the experiments. We have been learning and triangulating with the FDA on the endpoint for this clinical trial. We think it's a solid clinical trial, and we feel very strong about the opportunity in front of us. Let me end by calling out our excitement about ocular MG, which I think is equally in size and on medical needs. So opportunity would be equal in ocular MG as in seronegative MG. Thank you for the question. And as a reminder, we ask that you please limit yourself to one question only. Your next question comes from a line of Tom Smith from Leerink Partners. Your line is open. Hi. This is Matt [audio distortion] for Tom Smith. Thank you for taking the question. So following the approval of pre-filled syringe, what's your expectation on the split among users of the three product presentations of VYVGART, including IV VYVGART, subcutaneous Hytrulo, and pre-filled syringe in MG and CIDP? And similarly, how do you expect the payer mix to evolve following the—thank you. Yeah. Thanks for the question. So what we're seeing already with the launch of Hytrulo is that the majority of growth in patients, in new patients for MG and CIDP, is coming from Hytrulo. That was even with the butterfly execution, and we expect that that will continue and even accelerate with pre-filled syringe. Again, we're hearing from the market that people are really excited and that it really is a game changer having pre-filled syringe for self-injection available for patients. So we think that will be a growing portion of the market. Karl, did you want to take the question around the payer mix? I mean, I know we've shared in the past that it's 50/50 commercial Medicare, and I don't think we expect that to change significantly. Yeah. No. I mean, I think that is what it is today. I'm not expecting changes. We'll keep you updated if it does. Thank you. Thank you. Your next question comes from a line of Akash Tewari from Jefferies. Your line is open. Hey, this is Amy on for Akash. Thanks so much for taking our question. So one, is your fill-finish in Vetter considered substantially transformative? And if needed, how quickly could you move that into the U.S.? And then just a theoretical question on MFN. What mitigation measures could you potentially employ? Could you price your PFS differently ex-U.S.? It's a different product code. And would you consider pulling some of the other formulations? Thanks so much. Thanks, Amy, for these two questions. The first one, in terms of substantial transformation, I would use the drug substance manufacturing as your guide here, and the drug substance manufacturing, of course, is taking place on U.S. territory. Secondly, Karl already explained that I think we're in a strong position from an MFN point of view because we have shown the discipline in the way we have been setting and maintaining price in a narrow band globally in our key markets, so let's stay away from speculation, but I think we have strong cards to navigate whatever the future will bring us on these two fronts. Thank you. Your next question comes from a line of Charles Pitman-King from Barclays. Your line is open. Hi, guys. Thanks so much for taking my questions. Just a question on kind of Part B, Part D movements. If you could just give us a little bit more insight on what the actual price differential is between a Part B and Part D patient over one Q, I think that would be very helpful. And then just kind of following on from that, thinking about the kind of future split of patients, I mean, I think you kind of highlighted PFS is expected to become an increasing proportion going forwards. But given you've already been seeing these Part B patients move to Part D in the $2,000 copay related to the redesign, how do you expect IV to grow from here? Or should we expect—what's the future split of the three administrations? Thank you. Thank you. I mean, at a high level, the difference between the net price for a Part B and a Part D would be with 20% incremental rebate, which we have to pay under Part D for delta to CMS for patients who are on catastrophic. So that's at a high level of the difference between the two. In terms of the presentations going forward, remember we said that in the U.S., we think IV will always continue to be important for the U.S. market. Think of a buy-and-bill customer, so physician preference and so forth. But over time, from where we are today, and today we already have a minority, but we already have Part D for delta patients, over time, that mix will increase, and you're going to see a greater proportion of patients in D for delta. Thank you for the question, Charles. Your next question comes from a line of Myles Minter from William Blair. Your line is open. Hi. Thanks for taking the question. Just on VYVGART Hytrulo used in CIDP. I think you mentioned 85%-90% of those patients were switch patients. Can you just comment on the incidence of CIDP disease worsening when you make that switch? Just wondering if you have any real-world data. I think someone's presented it at AAN. Thanks very much. Yeah. Thanks, Myles, for the question. So I refer to the great conversation we had with Dr. Karam in the panel conversation during AAN. The first thing you need to know in CIDP is that whatever switch you consider to do, be it from steroids to immunoglobulins or vice versa or to VYVGART, there's always an expectation and a possibility that the patient will relapse. So this is a fact. You also see that in the IVIG, SCIG switch studies. I think the symptom worsening, which we have seen in the context of the ADHERE trial, is perfectly in line with those historical studies. And in the real world, actually, it's a relatively small phenomenon. We see low single-digit reporting on CIDP worsening. So the vast majority of our physicians are doing it the right way. It seems like switching to VYVGART one week after the last dose of IVIG is a recipe for success, but we're trying to document that in our phase IV switch study where we really try to collect evidence on how to switch best. So it is a known phenomenon in CIDP, and it looks like we're navigating that quite well. Thanks for the question. Your next question comes from a line of Suzanne van Voorthuizen from Kempen. Your line is open. Hi, Tim. This is Suzanne from Kempen. Thanks for taking my question. Could you please elaborate a bit more on how you look at empasiprubart relative to VYVGART in CIDP? Given the pivotal trial for empasiprubart is different than what you did for VYVGART, can you share how you're thinking about the positioning of each product and comment how the commercial opportunity looks like for each molecule in this indication, perhaps relative to each other? Thank you. Thanks, Suzanne. Thanks for being with us, and thanks for the great questions. So CIDP is a heterogeneous disease. I think the ADHERE trial, which was the biggest and the highest quality trial ever done in the CIDP space, is clearly demonstrating that pathogenic IgGs drive disease, at least in about 70%-75% of the patients. The question is then, why do the other patients not respond? There is a suspicion that complement is in play through pathogenic IgM antibodies. And we have pretty strong translational data in hand for empa in CIDP. Now, we do not want to niche empa into kind of refractory setting only. We really want to give this great molecule the fullest chance of success in the CIDP setting. So that's why we have designed the clinical trial you all see and let the data speak. I think this is a significant market, a significant opportunity, which can harbor multiple innovative molecules to optimally address the patient needs. So let the data speak now. Thank you for the question. Your next question comes from a line of Yatin Suneja from Guggenheim. Your line is open. Hey, guys. Thank you for taking my question. The question is on the GMG side. Could you just talk about the relative penetration in the targeted patient population you have achieved? Also, I think in the past, you have said that at least in myasthenia gravis, you are consistently seeing $40 million-$50 million worth of quarter-to-quarter growth. Is that the same? Is that what you are seeing now? And how should we think about the growth just purely in GMG? And any impact of some competition, whether it's the CD19 or anything else that you might be seeing or complement? Yeah. Thanks for the question. Always appreciate being able to talk about MG growth 13 quarters into launch and the fact that we're still delivering that consistent cadence of quarter-over-quarter growth, and to your question, I would say we are seeing consistent penetration into the earlier line. I mentioned that before. More than 60% of our patients are coming from earlier line, and what we're seeing as part of that is that the share of the market treated by biologics is growing substantially, and VYVGART is leading that growth with the number one market share. We're growing that number one market share in all of our major markets. Still, I would say at the early stages in terms of penetration. We updated the TAM to 60,000, you'll recall, last year. And with that, I think you can see that we're in the early stages of the growth curve for MG, even though we're 13 quarters into the launch. And what you can expect and what we expect is consistent and continued growth, whether you look at new patient starts, at prescriber growth, or the metric that you mentioned, which is revenue growth. When you take a line through it since launch, I think we've been delivering that consistent growth on average since launch, and we expect that to continue. Tim, did you have something to add? No, I've said it. And you can clearly see that we have broken out of the refractory patient population, right? What it takes to really move first line and lead in the first line is the clean safety profile, which we have demonstrated for the drug. Remember what we said in the prepared remarks? No black box, no need for vaccination, no labs, no monitoring. That's a very powerful profile to go frontline as a biological. And what we see, right, Karen, is that about 60% of the new patients coming on drug comes straight from the orals. And that is where the growth opportunity is in front of us. And we think PFS will continue to fuel that. That's right. Your next question comes from a line of Andy Chen from Wolfe Research. Your line is open. Hey, thank you for taking the question and back to the topic of Most Favored Nation. So, Karl, I understand that you talked about a narrow band. And just wondering if that narrow band is less than the 20% discount that you will have to pay on Part D, or is it more than the 20%? Just curious if there's a way for you to push your patients to the Part D to minimize exposure just because Part D price cut is less likely than a Part B price cut if Most Favored Nation comes to play. Thank you. I mean, Andy, I think I don't want to talk about percentages, but I think the reference to Most Favored Nation here is on list prices. And I think in list prices, we are in the narrow price band. And I think we don't want to speculate on where the law will end. It's still in concept phase. So for now, I think I'll stop there. But maybe, Tim, you want to add something? Yeah. We're not in the business of pushing patients into certain directions. I think what we're trying to offer is the broadest product offering possible to satisfy the needs of the different patient segments. So I think what you guys are seeing in Q1 is a very strong appetite of patients to move into self-administration at home or product administration at home. That's where this acceleration under Medicare Part D is coming. But, guys, this is the force you need in order to spectacularly grow your market. So following the patient demands, satisfying the demands is the best way for growth going forward. I think you basically see a signal here that patients are eagerly awaiting the PFS. Your next question comes from a line of David Nierengarten from Wedbush Securities. Your line is open. Hey, thanks for squeezing me in. I have one question, which is, are the dynamics as you see patients getting treated with ocular MG currently, are those dynamics different from generalized MG and how that might affect your commercialization plans and duration of treatment, things like that, and that potential expansion? Thanks. Yeah. David, we don't want to squeeze you, right? I mean, your question is valuable to us. Ocular MG, higher medical needs, which we overlooked in the beginning when we were approaching the MG market. It's very debilitating to have ocular MG. There is no ability to work on a screen, drive a car. There's a big social stigma associated with the symptoms, etc. So the truth is that today, the toolbox to treat these patients is even more limited. You would typically see that these patients are being treated with Mestinon and a high dose of corticosteroids. We know what the detrimental effects are of high-dose corticosteroids used chronically. And we really are on a campaign of steroid tapering. We have strategic alliance with Steritas. We think the moment is ripe to actually offer these patients a real alternative with the benefit-risk profile of VYVGART. So high unmet need, very limited treatment toolbox, and an opportunity to disrupt that treatment paradigm. Thank you for the question. Your next question comes from a line of Gavin Clark-Gartner from Evercore ISI. Your line is open. Hey, guys. Apologies, but it's one more net price question. For the prefilled syringe, what are your current assumptions for the number of payer contracts that will include VBAs moving forward? Specifically wondering on the CIDP side and wondering if this could offset the gross-to-net a little bit. Thank you. Yeah. So maybe just to start before I hand it over to Karl, to take a step back and remind everyone that our strategy with VYVGART is to provide as broader access as possible to patients. And certainly, that we don't want them to be choosing between product presentation based on price. We want them to have access and be able to choose the product presentation that fits into their life. So that's the strategy that we're pursuing. And what we've seen, whether it's with the MG launch, the CIDP launch, and what we expect with the PFS launch, is that our market access team are experts at getting really good access in place quickly for patients. And we expect that will be the same, and the agreements will be signed quickly to get that access in place for pre-filled syringe. Karl, did you have anything else to add on the details? I mean, Gavin, I think the only thing I will say is that generally, VBAs are less important in the pharmacy channel than the medical channel. So I think we'll leave it at that, and let's negotiate the contracts during the next few weeks and months. Your next question comes from a line of Samantha Semenkow from Citi. Your line is open. Hi, good morning. Thanks very much for taking the question. Another one on CIDP. I'm wondering, how has the discontinuation rate in CIDP trended? Are you still seeing physicians giving the majority of patients a 12-week trial, or has that trended down as they gain more experience with VYVGART in this population? Thanks very much. Yeah. Thanks for the question. So in terms of CIDP, we are still seeing that doctors are giving that 12-week trial. And what we've seen as the launch has matured is that there has been a little bit of an uptick in discontinuation, more towards what you'd expect based on the ADHERE trial. But there is still a significant gap, and I would say we're below that discontinuation rate. So what we're seeing is patients starting on VYVGART, having a positive experience, and staying on VYVGART. Your next question comes from a line of Leland Gershell from Oppenheimer. Your line is open. Great. Thanks for taking the questions. Just two from us, if we can, just with respect to the upcoming data from the switch study from IVIG to VYVGART in CIDP. Just given the dynamics there and the positive launch, just wondering how critical you see those data for physicians to effect a switch in their patients. And then also want to ask, with respect to 119, later this year, we'll see the POC data in CMS. There are a few clinical endpoints being looked at. Just wondering if you have any threshold in mind when you look at those data for taking that program forward in CMS. Thank you. Yep. Thank you for the two questions. So the significance of the IVIG switch study is very simple. I think the ADHERE trial was a very ambitious trial, but there's only so much you can answer in one clinical trial. So we addressed that this is an IG-driven disease. We addressed the magnitude of the effects you can show across the board in CIDP patients. But we did not really study in detail the switch dynamic. Remember, patients had to worsen so they could demonstrate active disease before they came on trial. That is a bit of an artificial experimental setting. The phase four trial is now investigating a practical question. How do you really switch an IVIG or SCIG patient to VYVGART? The simple trial design is a phase four, and it's meant to give some practical handle to treating physicians on how to do the switch. So I think it's an important data point. With regards to 119, a molecule which is very close to my heart, congenital myasthenic syndrome. What we learn about these patients in the natural history study is that they actually look very much like the autoimmune myasthenic patients. There is a very strong fatigability aspect to their disease. Limb girdle is really affected, so weakness of the shoulders, weakness of the hips. And therefore, we're really testing a menu of endpoints, testing which ones are really truly capturing the nature of the disease. The classical ADL and QMG measures are in there, and we know what the clinical thresholds are for clinical relevance. So we will be looking through that lens at our patients, and we will inform you, of course, when we have the data in hand. Thank you for the question. Your next question comes from a line of Joel Beatty from Baird. Your line is open. Good morning. Thanks for taking our question. Just kind of a longer-term one. I know the PFS rollout is just taking place, but have you started turning your attention a little bit now to firming up timelines and strategy regarding the auto-injector? Thank you. Yeah. Thanks for the question. Appreciate zooming out and looking over the long term. And yes, our team is consistently working on not just the auto-injector, but how we can innovate for patients overall. In terms of the auto-injector, we continue with that development plan. The latest update we had provided is that we're moving it into being able to understand how to produce it at larger capacity. But everything's on track, and we look forward to being able to bring continued innovation to patients in the future. Your last question today comes from a line of Xian Deng from UBS. Your line is open. Hi. Thank you so much for taking my question. So really, thank you for the comment on European and U.S. have very similar list price. But just wondering, could you give us some color on the sort of difference in terms of the net price, please? I'm sort of asking in relationship to how should we think about the commercial opportunity for PFS in Europe? Because on one hand, Europe does have this sort of lack of IV infrastructure compared to the U.S., but then on the other hand, probably we have less net price. So how should we think about that, please? Thank you. Yeah. Thanks for the question. And maybe to start with, I'll reinforce something that Karl had said. In terms of our ex-U.S. expansion, we've taken a very disciplined approach to ensure financial sustainability as we provide access to patients around the world with VYVGART. So I think we're very well positioned in terms of our net price from that perspective. And you're exactly right. We see the PFS opportunity as a big opportunity ex-US because of the hospital dynamics that you mentioned. We've already seen the first patient dosed in Germany. What we saw with the Hytrulo butterfly execution is a very fast conversion in Europe, in particular, of patients from IV to the butterfly execution of Hytrulo. And we think that will accelerate with PFS, and it will certainly help to accelerate and continue our growth in the rest of the world or outside of the U.S. in the future. So we're really excited about the opportunity for PFS, not just in the U.S., but around the globe with launches coming. Thanks for the question. This concludes today's conference call. Thank you for your participation. You may now disconnect.