argenx SE (ARGX) Earnings Call Transcript & Summary

Good day. My name is Rob, and I will be your conference operator today. I would like to welcome everyone to the call. [Operator Instructions]. Thank you. I'd like to introduce Beth DelGiacco, Vice President Global Head of Corporate Communications and Investor Relations. You may now begin.

Thanks, Rob. We're very excited to be here today to discuss the FDA approval of VYVGART Hytrulo in Chronic Inflammatory Demyelinating Polyneuropathy or CIDP. Today's press release and the corresponding presentation can be found on our website at argenx.com. Before we begin, I'd like to remind you on Slide 2 that forward-looking statements may be presented during this call. These may include statements about our future expectations, clinical developments, regulatory time lines, 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 those statements in relation to actual results unless required by law. I'm joined on the call today by Tim Van Hauwermeiren, Chief Executive Officer; Luc Truyen, Chief Medical Officer; and Karen Massey, Chief Operating Officer. Peter Ulrichts, Chief Scientific Officer; and Karl Gubitz, Chief Financial Officer, will be available for the question-and-answer portion. I'll now turn the call to Tim.

Thank you, Beth, and welcome, everyone. Today is another historic day in autoimmunity as we continue to deliver our novel targeted medicine to new patient populations. VYVGART Hytrulo was approved by the FDA for the treatment of adult patients with chronic inflammatory demyelinating polyneuropathy. This is a momentous innovation for CIDP patients and the caregivers, who have all been waiting for more options in the treatment of this chronic progressive disease, and I am thrilled to be sharing this important milestone with them today. For decades, the diagnosis of an autoimmune disease meant that you faced chronic treatments that commit significant side effects and treatment burden. But for patients, this has been the only option to keep disease symptoms under control or from progressing. We are now addressing this dilemma with novel innovations like VYVGART with a raising patient expectations on what an autoimmune diagnosis can mean. VYVGART Hytrulo is the first FcRn blocker to be approved for CIDP and represents the first new mechanism of action in the treatment paradigm in more than 30 years. Today's approval in CIDP also represents our third approved autoimmune indication for the VYVGART franchise, following generalized myasthenia gravis and immune thrombocytopenia. This is a big day for CIDP patients and a big day in the argenx mission to transform autoimmunity. Slide 5. After seeing the transformational review data last summer, we had a strong sense of urgency to advance VYVGART Hytrulo to approval as quickly as possible. We used a priority review voucher, shortening the review time from 10 months to 6 months, allowing us to bring this new treatment to patients that much sooner. VYVGART Hytrulo is indicated for the treatment of CIDP in adult patients. We are really happy with the broad data we receive, which reflects important decisions that we made in the ADHERE trial design. We enrolled patients across the treatment paradigm, including those who are treatment naive or currently on steroids or IVIg. What we see in the label is the best case scenario that regardless of prior treatment, VYVGART Hytrulo can provide rapid and durable responses. The recommended dosing in CIDP is once weekly, which is what was studied in the trial and can be administered through a convenient 30 to 90-second subcutaneous injection by a health care professional. The safety profile is consistent with the label in gMG. Slide 6. CIDP is a rare also progressive debilitating neuromuscular condition that can also seriously impact patients' emotional and mental health. When we initiate development in this indication, it was important to us to understand the burden patients face, and we did this by partnering with the GBS|CIDP Foundation and listening to and learning directly from patients and caregivers. The feedback has been consistent that patients deserve more. Even with current treatments available, 88% of patients say they continue to experience residual neurological symptoms. Some of the other themes we heard include patients are still facing diagnostic delays, which can lead to irreversible impairments, given the progressive nature of the disease. They experienced significant pain and numbness, which was described by many as feeling like our hands and feet are on fire. A CIDP diagnosis can severely limit the ability to perform daily activities, which can come with feelings of isolation and depression in the sense of losing one's independence. We met, Julie, who was diagnosed at the time when she has 2 [ dumb ] children, while also caring for her terminally ill husband. She had to figure out how to navigate daily tasks without the help of her family and while struggling the debilitating physical symptoms. She couldn't reach up in her cabinets because she couldn't stand on her toes without support. She couldn't easily see her kids because her fine motor skills have deteriorated. Even today, many years later, she is tied to her treatment schedule and is getting IVIg infusions every 2 weeks. Another patient Jamilah, who is pictured on the slide. She was a dancer before CIDP put her in a wheelchair within a few months of diagnosis. These are the stories that motivate our team every day that we can bring hope to the CIDP community by translating our innovative science into better treatment outcomes for patients. And today, with the approval of VYVGART Hytrulo, we are delivering on this commitment. I'll now turn the call to Luc, who will walk through the ADHERE trial design and the transformational data that served as the basis for the approval today.

Thank you, Tim. Slide 7. Today's approval marks a significant win for the CIDP community and for the argenx team, who have worked tirelessly together to bring a new innovation to the CIDP treatment paradigm. The compelling clinical efficacy and safety data that supported the approval of VYVGART came from the global registrational ADHERE trial and the associated open-label extension study ADHERE-Plus. Slide 8. As the largest CIDP trial ever conducted, the ADHERE study, united the CIDP patient and scientific humanities together in the shared pursuit of a new treatment option. We are proud that ADHERE set a new standard for how to run CIDP studies and ultimately demonstrated that a majority of patients responded to VYVGART Hytrulo regardless of prior treatment history. I will now run through the design at a high level. Prior to treatment, we leverage both screening and running periods to optimize our chances of trial success. During screening, patients were evaluated by an independent committee to ensure that we enroll true CIDP patients due to the high rate of misdiagnosis. We also implemented a treatment with all periods to confirm active disease. 322 patients entered Stage A and received VYVGART Hytrulo to classify as a responder in advance to the randomized placebo-controlled Stage B, patients have to demonstrate evidence of clinical improvement by regaining what we had lost during the treatment withdrawal periods on the same scale, adjusted INCAT, I-RODS or grip strength. ECI had to be demonstrated at 2 consecutive visits. 221 patients and end-of-stage VYVGART study, where patients were treated for up to 48 weeks or until they had a relapse. This was defined as a one or more point worsening on the INCAT scale from Stage B baseline. The primary end points was the relative risk of relapse for the hazard ratio based on time to first adjusted INCAT deterioration of 1 or more points. An impressive 99% of patients elected to continue treatment in open-label study, further supporting VYVGART Hytrulo as a therapeutic option to meet the data demand for innovation. Slide 9. We recently highlighted our stellar ADHERE data at AAN, which was well received by the neurology community. Overall, VYVGART Hytrulo induced fast, deep and durable responses in a broad CIDP population. Beginning with Stage A, the majority of the patients up to 69% showed improvement in functional ability and important criteria for patients and HCPs. Further, we saw rapid onset of this response with 40% of patients demonstrating this clinically meaningful improvement by week 4. Also recall that this was the earliest time point in which this criteria could have been met. These data provided the evidence necessary to support the key findings that CIDP is an IgG-mediated disease. Moving to stage B, VYVGART Hytrulo met its primary endpoint, significantly reducing the risk of relapse by 61% with similar responses observed across CIDP therapy subgroups. Slide 10. One of the more notable takeaways we observed from ADHERE was that many patients, who continued on therapy through Stage B actually saw functional improvement as defined by the change in INCAT score from baseline. 81% of treated patients demonstrated over 1 point improvement on the adjusted INCAT as compared to baseline Stage A in ADHERE which includes almost 30%, we improved 3 or more points. This degree of change can signify the difference between an individual using a wheelchair and an individual walking. And we actually observed this during Stage A, where we saw a number of wheelchair-bound patients, leading stage A free from their wheelchair. Slide 11. Finally, Slide 11 shows the summary of adverse events seen at here. Most adverse events were considered mild or moderate and no new safety signals were observed with up to 40 weeks of weekly treatment -- 48 weeks of weekly treatment. We observed a very low incidence of headaches, which were mostly mild transient and infections, both were balanced across the treatment placebo arms. The most common adverse event was injection site reactions, indeed occurred at a low overall rate of incidence and most commonly during first injections. These safety data combined with the efficacy data highlight a consistently favorable benefit risk profile of VYVGART Hytrulo. I will now hand the call to Karen, who will discuss our commercial launch strategy. Karen?

Thank you, Luc. Slide 13. Let me just begin by saying I am absolutely thrilled with today's outcome and what it means for CIDP patients and their families. I want to express my gratitude to the entire argenx team, who continues to innovate on behalf of patients suffering from rare autoimmune diseases. Our goal is to elevate expectations and outcomes for patients. And now we have the opportunity to do so for CIDP with VYVGART Hytrulo. Slide 14. We have an incredibly exciting launch ahead of us as we introduced the first and only targeted non-plasma-derived therapy approved for the treatment of CIDP, this is the first new MOA in CIDP in over 3 decades. The team is ready to deploy a launch strategy to provide patients access as quickly as possible, while also putting the necessary pieces in motion to maximize our long-term patient impact. We have 4 core strategies with our CIDP launch that we need to deliver across our stakeholders, patients, prescribers and payers. First, we'll empower patients to demand more from their treatment. We know, but with a progressive disease, patients can be hesitant to switch treatments to arming the patient with the necessary information will be an important driver of demand. Second, we also want to leverage the success of My VYVGART Path from our MG launch by providing best-in-class patient support. Third, we'll drive rapid health care provider adoption by reaching the right targets, sharing the strength of our data in CIDP. And last, we will work to get payer policies in place as quickly as possible to deliver patients broad access to treatment. Slide 15. Let's start with the patient and what the near-term opportunity looks like. From our market research, there are an estimated 24,000 CIDP patients in the U.S. who are currently on treatment. We consider this to be the total addressable population. In the initial stages of the launch, we will focus on patients we believe are most likely to switch from their current treatment, which would be those that have insufficient efficacy, for example, symptoms, waxing and waning or disease progression, patients who are unable or unwilling to tolerate side effects of their current therapy or patients who are unable or unwilling to carry the treatment burden of their current therapy. This brings us to 12,000 patients for our initial target population, who are not well managed on current therapy. This number will grow over time as patients and physicians gain more experience with VYVGART Hytrulo towards our ultimate aspiration to be the standard of care in CIDP. Slide 16. Let's move on to the patient experience. We understand that starting a new therapy is not always an easy choice, and CIDP patients, in particular, may be hesitant to make the switch given the progressive nature of the disease. We've talked about this in the past, the stickiness that patients know well. First, we want to empower patients to raise their voice and ask for better from their treatments. We plan to activate conversations within the CIDP community, among CIDP patients and between patients and their care teams to elevate awareness and interest in VYVGART Hytrulo. Once a CIDP patient and their care team makes the choice to start VYVGART Hytrulo, we offer additional support through My VYVGART Path. Through this program, both MG and CIDP patients are able to navigate their personal treatment journey with a nurse case manager and dedicated support team. My VYVGART path also helps patients navigate the insurance process and provide information on financial assistance programs that may be available to them. Slide 17. Moving to our third launch strategy to drive rapid adoption among health care providers. Over the past 2 years, we have established argenx as a trusted and credible partner to neurologists in the care of MG patients. We will build on this solid foundation with the CIDP launch by reaching the right physicians, delivering the most impactful messages based on the ADHERE data and then providing education in navigating the reimbursement process. Based on our market research, there are 10,000 target neurologists, which reflects our updated assessment of the MG opportunity as well as new CIDP targets. We expect that physicians who are already prescribing VYVGART for gMG will be more likely to write for CIDP. And there is approximately 72% overlap in prescribers, who treat both. So we will focus our initial efforts on neurologists with VYVGART experience. We've also learned that CIDP patients are more often treated in community practices than with MG. Physician education will be key, particularly with such an innovative mechanism of action. So we'll take the approach of meeting physicians where they are, both in and outside their practices to drive awareness that VYVGART Hytrulo works fast, showed demonstrated functional benefits and has established safety profile. In addition, we made the strategic decision earlier this year to increase our sales force. This allows us to meet the growing demand from our MG launch and to ensure our teams are well positioned to reach the right physicians for our CIDP launch. We were fortunate to attract very experienced candidates for these roles, and the strength of our people and the relationships they have with key neurologists remain an important differentiator for argenx. We also expanded our broader field capabilities, including roles dedicated to educating physician offices about the reimbursement process. Overall, we believe we have the right team and the right strategies to drive adoption of this new precision tool available to treat CIDP. Slide 18. This brings us to the last part of our strategy our commitment to securing the broadest access possible for CIDP patients. We're taking a similar approach with CIDP as we did with MG, which means that we have already been engaging with payers to share the differentiated value proposition we can offer to CIDP patients based on strong efficacy and safety results from ADHERE and the ease of administration that we can offer with our subcutaneous injection. We're going to move as quickly as possible towards published policies, leveraging the credibility and trust that we've already built with payers. Our team is working towards getting value-based agreements in place during the second half of 2024, which will be designed with a similar principle of those for MG to enable access to VYVGART for eligible patients and to manage the exposure of payers based on the expected utilization of treatment across their patient populations. We anticipate that the annual net revenue per patient will be approximately $450,000, and this is based on the vial price for VYVGART Hytrulo, which is the same as MG, the projected utilization of VYVGART Hytrulo in clinical practice and the anticipated payer mix between commercial and public. Lastly and importantly, we expect patients to have an out-of-pocket cost similar to MG and similar to IVIg. My VYVGART Path will help patients navigate any questions on coverage throughout the process. Slide 19. We continue to deliver on our multi-dimensional growth strategy and several global approvals are already underway. To date, we have successfully filed the CIDP approval in Japan, China and in Europe. As part of our long-term commitment to innovate on the patient experience, we're also happy to share that we have successfully submitted the filing of our prefilled syringe for both CIDP and MG. The PFS study was designed to support self-administration, which over time, will help us reach even more patients in earlier line treatments. In summary, I'm confident in our commercial engine, powered by our incredibly talented team that is purpose-built to deliver continued growth as we expand into new indications, new geographies and new product presentations. It is a really exciting time to be part of this team as we maximize the impact of this transformative first-in-class molecule and the impact it can have for patients. I'll hand it back to Tim.

Thank you, Karen. Reflecting on today's incredible wins, as we think comes back to our pioneering mission to innovate on behalf of patients are our reason of existence with deep conviction in our science and our people redefined initial skepticism. We heard CIDP was too complex to tackle and that patients should accept the status quo of their treatments. But here we are today standing at the finish line of an exciting development path, offering the same patients a new hope. We pioneered novel biology to establish CIDP as an IgG-mediated disease executed on a highly innovative trial design and navigated the review process with the FDA to bring us to the approval today. We're eager to drive transformational impact as we evolve expectations for CIDP with VYVGART Hytrulo. I will be remiss if I didn't pause press my gratitudes to all of our patients, physicians and collaborators. Innovation does not happen in a vacuum. We brought together a highly collaborative team from different backgrounds aligned by one mission. I would also like to thank our long-term shareholders for supporting us on this mission. And last but not least, our team and argenx, who made this happen. Thank you. I would now like to open the call for your questions.

[Operator Instructions] Your first question comes from the line of Allison Bratzel from Piper Sandler.

I just want to extend a big congratulations to the whole team on this approval. So just a question for me on average net revenue per patient. You talked about [ $450,000 ] per patient per year. Could you just walk us through or help us understand the inputs or assumptions that went into that number? Does that take into account the potential for patients to move to every-other week dosing longer term? And just how does that $450,000 compared to the average price per patient on IVIg maintenance?

Thank you, Allison, and thank you for being with us today. This exciting call. This is a question I'm going to hand over to Karen. Karen?

Yes. Thanks for the question. This is an important one. So let me just go some of the assumptions that went into this. So as you say, the net revenue per patient is based on the established price per vial, which is the same as MG. And then what we looked at was real-world utilization data as you correctly called out, is based on it ADHERE-Plus where we have some insights into the biweekly dosing as well as some analogs for the other assumptions that get us to that real-world utilization. And finally, the payer mix, the percentage of patients that will be covered by value-based agreements. And that's how we get to the average net revenue per patient of $450,000. Last really important question, though, which is the comparison to IVIg. The data that we see and from what we understand is that the range is between -- for a chronic patient is between $100,000 and $400,000 per patient, but the average or typical patient for IVIg is around $250,000 per year for a chronic patient. What's most important, though, to keep in mind, as you're thinking about that consideration is the out-of-pocket cost for patients. And we expect that the out-of-pocket cost for patients will be approximately the same. So VYVGART Hytrulo CIDP and MG, and that's in line with about what they expect for IVIg as well.

Your next question comes from the line of Tazeen Ahmad from Bank of America.

Congrats on the extended approval. I just wanted to get some clarity, just given the fact that you've gotten a fuller label with no restrictions on how you're thinking about use of first line versus switch patients, it seems like you're going to be focusing on switch patients, but I just wanted to clarify what your longer term plan is?

Yes. And thank you, Tazeen, for being with us tonight. And this is a great question. Before I hand over to Karen, to walk us through how we think the adoption curve is going to go in the launch, I would like to express how happy we are with the very broad label. I mean this is the best-case scenario. And I think it's a best-case scenario resulting from the fossil trial design and the careful execution. If you look at the data, no matter what your prior therapy was, we legal right to respond to VYVGART Hytrulo. So this is a fantastic database position. And Karen, could you maybe expand on how you think the adoption curve would look like?

Yes, absolutely. Thanks for the question. So as we shared, we -- the total addressable population that we see is 41,000 patients with CIDP in the U.S. with the initial target that launch of 12,000. So the way that we think about it is that our aspiration is to become the standard of care and to be able to reach that total addressable market. At launch, we will be focusing on those patients that are dissatisfied with their current treatment. And according to our market research, that gets us to an addressable market at launch of about 12,000 patients.

Your next question comes from the line of Yaron Werber from TD Cowen.

Yes. Congrats team. Really good outcomes. So maybe just a couple of questions to piggyback on Tazeen's question. Do you have any time how many new patients, first-line patients come in to the market every year because we would anticipate you'll get the first line? And how many patients are failing steroids specifically? And then secondly, should we assume that in the OLE patients sell, it sounds like they were still getting weekly therapy?

Thank you. Karen, do you feel comfortable to disclose what we are ready to disclose?

Yes, absolutely. Happy to share. So the way I think about it, Yaron, is that this market is prevalent versus incident market. So really, that's why we shared that the patient population is mostly focused on those already diagnosed and treated and that 24,000. I don't have the specific numbers or the breakdown of those that are failing on steroids, but the 12,000 patients that we shared that are not currently well managed on their therapy today, that includes IVIg as well as steroids and some other unapproved therapies. So we believe that the initial adoption based on the strength of our data across efficacy and safety as well as the treatment burden will be in those patients that are not well managed on their current therapy.

And then the question on the OLE mechanics. I don't know, Tim or Luke, if you want to take that, whether they went to weekly or biweekly.

Yes, I can take that.

So okay, go ahead, Luc.

Well, I mean, this open-label is still ongoing. And a subpart of these patients have the opportunity to go and elect to go to biweekly or even every 3 weeks, depending on how they fare, but this is an evolving data set, and we will report on that at a time when we have an update available.

Your next question comes from the line of Derek Archila from Wells Fargo.

Let me add my congratulations on the approval. So just two brief ones. I guess given the pricing here for CIDP thinking ahead for future indications, how should we think about Hytrulo pricing where it's being dosed weekly or in this type of scheme? So that's question #1. And just maybe a clarification/question. So I guess how many of the 7,200 neurologists that you're going to be focused on here with overlap with MG and CIDP have already prescribed VYVGART? I don't know, you might have said it, but maybe I missed it.

Maybe start with the first question, Karen, and then you can talk about the question of the 7,200 neurologists. So Derek we're unpacking pricing indication by indication when we launched with VYVGART in MG, VYVGART Hytrulo, the way we have been thinking about the price in MG was such that we would not be pricing ourselves out of any of our future planned indications, and that's exactly what you see in action here. So once the price of the drug has been set on a milligram basis, the other variables going into the pricing mix per indication given an in vivo's utilization and the payer mix. And what you see in the open-label extension study of VYVGART Hytrulo and MG Plus is that patients have the opportunity to basically start to space out the dosing, depending on how they were faring on the drug. And it's not unimaginable that for other indications, once you reach a maximum PD effect of the drug, you will not need weekly dosing going into maintenance therapy. So stay tuned on other indications, but I think we're showing it today for CIDP that we can perfectly navigate multiple indications based on the same original milligram price. Karen, do you want to talk about overlapping prescribers?

Yes, absolutely. Happy to. So we've updated the total number of prescribers to 10,000, and that reflects, two things -- two factors, just to set the ground in the foundation. One is that the MG opportunity is larger than we thought and the second is the addition of the CIDP targets, which we actually find a much more out in the community than MG. So that's the starting point. The question that what we shared in the Q1 earnings call, we currently have 2,700 prescribers for VYVGART in the U.S. and those will be certainly a big part of the initial focus. They have experience with VYVGART Hytrulo, and our data suggests that there'll be more rapid adoption amongst those prescribers.

Your next question comes from the line of Akash Tewari from Jefferies.

This is Amy on for Akash. Congrats on the approval. Just on the payer side, what are your expectations on how these payer policies go look? Do you think the payers will require any sort of through IVIg given the cost? And then also, could you clarify on some of these out-of-pocket costs that you alluded to earlier? And will you bring those type of data to the payers?

I'm going to hand over to Karl in a second, but let me start by the label. So the FDA has given us a very broad label and did not require any step-through. I mean this is an indication statements for the treatments of CIDP, which is, of course, a fantastic starting position for the life of the VYVGART Hytrulo in CIDP. Karl, would you mind explaining a little bit of the mechanics of how we're approaching the VBAs with payers, although, of course, we cannot disclose too many details because the discussions are still in full flux. Karl?

Yes, exactly. Yes. Thank you, Tim. Thank you, Amy. Yes, I think the discussions are ongoing. So yes, we won't say too much. But basically, what we aim to do is to provide certainty and predictability to the payers. And so we are saving the data with them, and we are in those negotiations. And I think once we concluded and then we can provide more information.

Your next question comes from the line of Thomas Smith from Leerink Partners.

Congrats on the approval. Maybe just a follow-up on the payer front. I'm just curious if there's a target in terms of the number of covered lives for this year? Or there's another metric that we can use to track the progress on the payer and access front. And then I can sneak in just a second question. Is there anything else you can share with respect to the expected time line for the FDA decision on the prefilled syringe?

Thank you, Thomas, for this question. We're not going to pin ourselves down on a certain target for pay policies in place. What we can say is that it took us for MG about 2 quarters to get these policies on the bulk of the policies in place and the team is going to work diligently to try and parallel the achievement, which we had for MG. Give us a couple of quarters, obviously, early in the launch, we will feed you with or supply you with some of the early launch KPIs just like we did for MG, and I think you will hear us talk about the percentage of policies, which we have secured within a given quarter going forward. So that's going to be one of the early launch parameters. For what concerns to prefilled syringed, super pleased with the team effort to know we submitted a very strong data file as we predicted before the end of the month. And now that's actually it's in the hands of the FDA that is no standard review plan for such a data package. So it's now in the hands of, and stay tuned. We will keep you informed as we go on the progress we make with the review and potential approval. Thanks for the question.

Your next question comes from the line of Alex Thompson from Stifel.

Congrats as well. I guess as a follow-up to the last question, can you talk a little bit about sort of the particular KPIs you expect to share over the next couple of quarters on the launch? That would be helpful.

Thank you, Alex, and thank you for being with us. And Karl, if you feel comfortable to talk about some of the early launch KPIs we would typically be discussing?

Yes. I think we're going to share the similar KPIs as what we've shared during MG. I don't want to make firm commitments now, but it would be around patient -- patients and prescribers. How many patients we have with good prescriber of the depth and breadth of prescribers. And of course, we want to give you enough information over you can work out, of course, a particularly good understanding of the revenue curve and the ramp of our loans. And that's our commitment to you. So more to come by at quarter end. Thank you.

Thanks, Karl.

Your next question comes from the line of Vikram Purohit from Morgan Stanley.

We just had one clarification on the sales force efforts. Because I think it was just mentioned that there's more of a CIDP patient base in the community setting versus what you see with MG, are you -- do you think the sales force is rightsized right now for the CIDP and MG opportunities? Or do you think there could be more investments over the coming quarters to build that out further?

Thank you, Vikram, and thank you. This is a great question. Karen, would you mind commenting on the efforts we have done to get launched ready?

Yes, absolutely. So to answer the question specifically on the field force, when we took a look at the strategy for expanding the field force, we looked at both the MG opportunity and the CIDP opportunity over the long term based on our latest learnings, and we sized for that so you can expect that we believe that we're well sized and well positioned moving forward. What's really important is that for the CIDP launch, it wasn't just about -- it's not just about the field force expansion so that we can make sure to drive adoption amongst health care providers, as you said, out in the community as well with the updated 10,000 targets, but also expanding capacity and capabilities in terms of how we support patients, so expanding our capacity in terms of My VYVGART Path and expanding our capabilities in terms of how we support reimbursement and patients getting started and staying on therapy for both MG and CIDP. So we're really excited. We're ready to go, and we're prepared for a launch on Monday.

Your next question comes from the line of Samantha Semenkow from Citi.

Let me add my congratulations on the approval. I just have one clarification on payers, the payer mix that you've referenced in CIDP. Can you just give a little bit more color on what that mix is? And is it different than what you've seen for gMG patients?

Yes. Thank you, Samantha. That's a good question. We do have an understanding of the likely payer mix going forward in CIDP. And maybe, Karen, you're best positioned to give a few comments on that.

Yes, absolutely. So what we look at in MG is a payer mix around 50-50, and at the moment, we're using the assumptions that are similar to that. As we move forward through the payer discussions as we see real-world utilization, then we'll update those KPIs in those figures.

And your next question comes from the line of Gavin Clark-Gartner from Evercore ISI.

Congrats on the approval. So I'm just wondering where some of that data came from that underpinned the $250,000 average IVIg price assumption? If my math is correct, that correlates to around 2 grams per kilogram per month for patients. And some of the prior trials in real world data I was seeing was closer to the 1 gram per kilogram range. Maybe those are more stable patients and maybe you have better data than I have. So I'm just wondering on how you got that assumption.

Yes. Thank you for the question. We have done extensive and AQR work on it. And actually, you will see in one of the upcoming conference, as you know, an extensive cost of detailing the methodology and the calculus behind the $250,000 numbers. These are data notes, which are expected from real-world utilization databases. So I think they're pretty accurate. We will disclose methodology and underpinnings of the data shortly in an upcoming conference.

Your next question comes from the line of David Seynnaeve from Degroof Petercam.

Congratulations on the pain and [indiscernible] label. Perhaps more of a modeling question following up on one of the previous ones. So in comparison to the last few years, how aggressive should we model further SG&A ramp up this year and beyond considering that you can leverage your existing MG sales force, of course, to a large extent, but also at the same time, keeping in mind that IVIg is so ingrained to the CIDP community? I mean obviously, you indicated the $500 million burn for this year, but any input on SG&A specifically would be appreciated.

Thank you, David, and thanks for being with us tonight. I appreciate it. Karl, would you mind giving some broad commentary on evolution of SG&A. Thank you.

Yes. Thank you. And David, you would have seen that in Q1, when we closed Q1, you saw an uptick in SG&A to around $236 million per quarter. That represented a significant investment, which Karen referenced in the U.S. commercial organization. So the expanded MG opportunity, but also for CIDP because that same infrastructure is going to promote both indications. So what you'll see in Q2 is a further, just to take into account the full quarter impact of that investment in Q1. But after that, the increases will be gradual and more modest, more linked to inflation that may be a little bit for geographical expansion because we're still waiting for pricing and reimbursement in some European markets, for example, where we need to invest more. But the short answer is the Q2 number is which should be you're running rate going forward, and that should more or less be SG&A which you're going to have in the next few quarters. Thank you, David.

Your next question comes from the line of Victor Flock from BNP Paribas.

Congrats for the approval. So on my side, can I ask for a bit of clarification on the $450,000 annual net revenue per patient? So that we take into account the fact that the dosing might evolve with the ongoing open-label extension? Or is it solely based on the weekly dosing?

Thank you, Victor, and thank you for being with us tonight despite the late hour here in Europe. As Karen explained, the projections which we have been sharing with payers has been informed by the dosing, not only as we saw it in the ADHERE trial, but also in the ADHERE-Plus trial. This trial is ongoing. The data are still maturing, but we do have a clear view on the ability to go from weekly to every other week or every 3 weeks dosing, and these data have informed the projections we have been sharing with the payers. So this is useful information for the PPA negotiation. And you're correct in your assumption that depend in there. Thank you for the question.

Your next question comes from the line of Myles Minter from William Blair.

Congrats on the approval. Just coming back to the patient funnel here. Do you have a sense on the percentage of patients that are diagnosed and moved to a treated status per year and also the percentage of those treated that actually moved to a not well-managed definition on an annual basis? Or are those numbers that we see on Slide 15, they're pretty study and the proportions there will remain stable over the years?

Thank you, Myles. Karen, would you mind giving a bit more color to the patient follow we just presented in the call?

Yes, absolutely. Thanks for the question. So I think the way to think about is that probably the ratios stay pretty consistent in terms of diagnosed and treated CIDP patients over time. We see that patients not well managed on current therapies at the moment at 12,000. And I mentioned what that's driven by. So maybe the insufficient efficacy, maybe not able to tolerate the side effects or able to take the treatment burden. Our goal is, over time, to become the standard of care for treated CIDP patients. And we believe that we can do that based on the fact that we are the first and only targeted non-plasma-derived therapy, and we can differentiate based on that clinical data. So over time, we believe that we'll be able to penetrate further into the TAM of 24,000, but our initial focus at launch is on that 12,000.

[Operator Instructions] Your next question of Xian Deng from UBS.

Just a question on the annual price of $450,000 per year. So just wondering if that's after rebate, right? And if after rebate, just wondering, just to think about your initial target patient numbers and time said, that gives you something like $5 billion already, and not to mention, you will have missing a [indiscernible] on top of that. I mean, historically, rare disease doesn't really have much rebate. But going forward, considering the potential size of peak sales. Just wondering what do you think about the rebate going forward? And do you expect that number to basically go down as you start to penetrate even your initial target size?

You thank you for your question. I will take this one. I think it's premature to comment on rebates. I think it is fair to say that in the Medicare Part B channels, where VYVGART and VYVGART Hytrulo play, there's not too much of rebating going on. You know that we have a PFS plan, a prefilled syringe plan, we submitted the dose with the FDA earlier this month, hopefully, with an approval not too late in the near future. And that, of course, is a product which we'll be launching through Medicare Part D, but I think rebating is much more business practice. And so I think you need to stay tuned on how the rebate dynamics will go. The conceptual thinking I'm going to share with you today is that these markets will get very competitive very rapidly. So I think you will see over time, downward pressure on the price than what innovation comes in, and the market is maturing. So for the moment, very little rebating going on, but going further into the future, I think it's going to be more part of the business practice. Thank you for the question.

Your next question comes from the line of Andy Chen from Wolfe Research.

Congratulations on the progress. So this question might be for Karen. So on Slide 15, I see you have 41,000 diagnosed CIDP patients. Just based on your understanding of this market, how much under diagnosis or undiagnosis or maybe misdiagnosis do you think is happening here? And this goes both ways. So like how much of CIDP do you think is misdiagnosed as a different disease? And how much of some other diseases do you think is misdiagnosed into that 41,000? I'm just thinking -- just curious about how much hidden opportunity or maybe hidden threat may be here. So the 12,000 patients that you're aiming to treat, how many of them may not really have CIDP?

Thank you, Andy. The numbers which we produced for our patient funnel they have been very carefully validated by, for example, demanding from the database, as you know, multiple independent diagnosis of CIDP. So I think we're pretty certain about these numbers, but your overall comment, I think, is correct. The lead in the marketplace and the list and learn about CIDP in both dynamics actually are valid. There is over diagnosis going on, but there's also significant underdiagnosis going on. And I don't know to what extent these two keep each other in balance, but I do believe MG is to be true is that with more innovation, and this is the first innovation coming in, in 30 years' time, this is most likely a market which will further grow and develop in terms of awareness going up, accuracy of diagnosis improving and patients -- more patients coming out of the wood work. So I would not be surprised to see an overall growth dynamic in the market and improved accuracy of diagnosis. But today, both our products -- both over and under diagnosis are currently happening. Thank you for your question.

This concludes our question-and-answer session and does conclude today's conference call. Thank you for your participation, and you may now disconnect.