Good morning, everyone, and welcome to the Argenx phase III ADAPT-SC trial top-line results conference call. At this time, all participants are in a listen-only mode. To follow the presentation, we ask that you navigate the slides as directed by Argenx management. There will be a question and answer session to follow. I would now like to introduce Beth DelGiacco, Vice President of Corporate Communications and Investor Relations at Argenx.
Thank you and good morning to everyone on the call. Earlier today, we issued a press release summarizing our positive top-line phase III ADAPT subQ trial results. The press release and the presentation for today's webcast can be found on our website. On the call today are Tim Van Hauwermeiren, our Chief Executive Officer, and Keith Woods, our Chief Operating Officer. Wim Parys, our Chief Medical Officer, will also be available for the Q&A session following prepared remarks. Before we begin, I'd like to remind you on slide two that forward-looking statements may be presented during this call. These may include statements about our future expectations, clinical development, 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 those statements in relation to actual results unless required by law. I will now turn the call over to Tim.
Thank you, Beth, and good morning to all. We are very happy to share with you today the positive top-line results from the phase III ADAPT-SC trial of subcutaneous efgartigimod in patients with generalized myasthenia gravis. We met the primary endpoint demonstrating non-inferiority between subQ efgartigimod and VYVGART IV based on total IgG reduction at day 29, a crucial pharmacodynamic marker that has a linear correlation to MG Disease Score improvement. Secondary clinical and safety endpoints also confirmed consistency between the subQ and IV products, so we will move forward in filing our BLA by the end of the year. We will get deeper into the trial design and data shortly, but I want to first talk about what this means for patients as we continue to honor our commitment to the GMG community. Patients are at the core of our mission.
We have spent the last few years listening to and learning from GMG patients and their supporters, and the feedback we hear is incredibly consistent. Despite currently available medications to control symptoms of GMG, patients experience substantial disease and treatment burden. This extends beyond just physical limitations and can include mental, social, and emotional stress as well. They can feel very isolated because even though there are 65,000 adults living in the United States with GMG, each patient experiences the course of their disease and treatment in a unique way. There is no one size fits all. Diagnosis can often be a long journey, and the variability of symptoms can take an emotional toll on patients. Over half of patients have been diagnosed with anxiety or depression on top of their GMG symptoms. A person's ability to live a well-rounded, fulfilling life substantially decreases with GMG.
63% of patients have stopped work or school entirely due to the burden of their disease or treatment. We also learned that GMG patients are in desperate need of new treatment options. Despite taking an average of 2.3 current treatments, over 60% continue to report poor wellbeing according to a WHO index. Last December, we were very proud to receive FDA approval of our first in class FcRn blocker, VYVGART. This allowed us to bring a new standard in GMG treatment to patients based on the efficacy and safety profile we demonstrated. Thanks to the hard work and dedication of our global team, we also received approval in Japan just a few weeks later. The U.S. launch is off to a good start, and we reported during our last earnings call that we are trending ahead of our internal plan.
Now, we intend to bring our subQ product forward globally to complement the VYVGART launch and to be able to deliver the broadest treatment offering in GMG. In developing our subQ products, we aim for a speed-to-market approach that builds on the repertoire of data we have shown to date. We went to the FDA with a proposed bridging strategy and used the following logic in highlighting our plan. We have shown consistent IgG reduction across all subjects dosed with efgartigimod. It doesn't matter if you're a healthy volunteer or a patient. A linear correlation between IgG reduction and disease score improvements, both on the MG ADL and QMG scores, and an identical PD effect between a fixed dose of 1000 mg subQ and the 10 mg/kg IV. Basic assumption for bridging IV to subQ was that comparable total IgG reductions would result in comparable efficacy.
The FDA aligned with our thinking, and you can see the ADAPT trial design on slide seven, where we used total IgG reduction as the primary endpoint measure. While we only needed 50 patients to power the primary endpoint, we enrolled 110 GMG patients to meet the FDA's proposed safety requirements. This included 91 acetylcholine receptor antibody-positive patients and 19 antibody negative. All were naive to efgartigimod and had to meet similar inclusion criteria as in ADAPT. After a two-week screening period, patients were randomized to receive one treatment cycle or four weekly doses of either VYVGART or subQ efgartigimod. The primary endpoint was taken one week after the last dose, and key secondary endpoints were measured throughout the full 10-week trial period.
There was no option for the treatment in this study, and after week 10, patients had the opportunity to roll over into an open-label extension study where they would all receive subQ efgartigimod. 105 of the 110 patients enrolled in ADAPT subQ entered the open-label extension study. To further support the safety database requirements, we also offered patients in the ADAPT+ open-label extension the option to switch over to the subQ open-label extension. Baseline characteristics were generally consistent between the subQ and IV arms and consistent with what we saw in ADAPT. On slide eight, you can see that we achieved the primary endpoint with a P value of smaller than 0.0001.
There is a near identical overlap of the PD effect between IV and subQ, and the curves should look very similar, familiar to what we have observed in all efgartigimod studies to date. Total IgGs start to go down after the first dose and reach a maximum PD effect one week after the fourth dose. We also included the PD curve from ADAPT in this chart to show the consistency. Pathogenic IgGs, while not pictured, show similar overlapping curves. Slide nine. The trial was not powered for efficacy, but there is great consistency across all measures between the IV and subQ arms in ADAPT subQ. 69% of both IV and subQ patients achieved at least a two-point reduction on the MG ADL score for at least four consecutive weeks.
Approximately 66% of subQ patients, compared to 52% of IV patients, achieved at least a three-point reduction on the QMG score for at least four consecutive weeks. Remember that MG ADL is a patient-reported, physician-documented measure, and QMG is considered more objective with physiological parameters taken. We like to see consistency across both disease scales, which we achieved in this trial. Minimal symptom expression continues to be an important metric in GMG because it means that patients are virtually symptom-free with an MG ADL of zero or one. In Adapt subQ, across all participants, we saw 37% of subQ patients and 38% of IV patients achieve MSE. On slide 10, we show the response curves, both MG ADL and QMG. This is an impressive efficacy profile with regards to speed of onset, depth of response that supports the MSE measure we just discussed.
This is also an independent verification of our ADAPT data in a similar patient population. Efgartigimod continues to do what we expect it to do, and we see a similar profile now between the two formulations. The safety profile from ADAPT subQ is shown on the next slide. You can see that there's a lot of consistency here as well with ADAPT and nothing too unexpected. We focused on the most frequent adverse events, which were injection site reactions. 18 of 21 were mild, transient, and resolved without intervention. The other three were moderate. Headaches, which were primarily mild, and fatigue, both of which looked balanced between the two treatment arms. Myasthenia gravis or re-emergence of symptoms, which is not unexpected in a trial design with this duration and that does not allow for the treatment.
These were very small numbers, typically happened at the end of the follow-up period, and all of the patients who rolled over to the OLE were responders when dosed again with efgartigimod. Then diarrhea, falling, urinary tract infections, and contusion, which skewed to IV. Overall, we believe we have a very exciting subQ product to add to our broad GMG treatment offering. Our long-term objective is to serve the GMG patient in the most complete and optimal way, and this is a big step towards achieving this. Before I turn the call over to Keith, I would like to take a minute to thank our team who has continued to deliver strong results on plan. This takes nothing short of a full team Herculean effort.
Keith is now going to share some of the regulatory and commercial considerations for subQ efgartigimod, and we will then open the call for your questions. Keith?
Thanks, Tim. We are very happy to be here today, having passed the first hurdle in our effort to bring subQ efgartigimod to GMG patients. Next slide, please. Our decision to develop subQ efgartigimod has always been about optionality. GMG is a disease that is experienced differently by every patient, so it makes sense that there are different preferences in how people want to be treated. We took this into account when we integrated an individualized dosing approach into our trial designs, but also when we chose to advance both IV and subQ formulations. We believe that having both IV and subQ options allows us to capture variation in how GMG patients want to be treated. As an example, there are patients who prefer not to self-administer or who enjoy going to the infusion center for the social interaction.
On the other side, there are patients with busy lives and enjoy the flexibility of shorter administration times. This was our goal when we signed an exclusive partnership with Halozyme in 2019, co-formulating efgartigimod with their enhanced drug delivery technology. The enhanced technology breaks through conventional subcutaneous volume limitations, allowing us to dose our biologic in a simple, single subcutaneous injection. Our Halozyme partnership has proven to be a good strategic decision. We are the only company that is developing an FcRn blocker that can be administered both as an IV infusion and as a single subcutaneous injection. By offering both, we hope to broaden our market opportunity and reach as many GMG patients as possible. I'd like to take a moment to thank the Halozyme team for their collaboration.
It has been a true partnership, which we believe will position us well for driving long-term value for our key stakeholders globally. With today's positive readout, subQ efgartigimod is set up to be our second product launch within our neuromuscular franchise. Our field teams are already out there today engaging with physicians, patients, and payers on VYVGART, and we want the subQ product to complement these efforts and broaden our offering to the GMG community. We have been encouraged by the initial traction that our field teams have gained with VYVGART, proving that there is a real need in the GMG market for new therapies. We shared earlier this month that we are pleased with the broad initial demand from our key stakeholders. After the first eight weeks of launch, we are trending ahead of plan.
For physicians, we have breadth and depth of prescribers, meaning it's not just a few doctors writing multiple scripts, but a wide cross-section of doctors from both academic and community centers. We are also seeing physicians write their second and third scripts. We see a breadth of patients that aligns with the ADAPT population, some that are on steroids or Mestinon alone, and some that are more refractory, and everything in between. Our payer draft policies are becoming available with the majority closely aligned to the VYVGART label, enabling broad use. Our plan is to advance forward with the BLA filing by the end of this year in the U.S. Similar to the regulatory path for VYVGART, Japan and Europe will follow the U.S. at a similar cadence. You will recall that we will be submitting a separate BLA for the subQ product.
By co-formulating efgartigimod with Halozyme's ENHANZE technology, we have a completely different product that will have a different BLA, a different brand name, and potentially a different price if we choose. We have not made the decision on whether to use our priority review voucher for the subQ submission. Regardless, we currently expect an approval and launch in the U.S. in 2023. We are very excited with where we stand today and our goal to bring broad product offerings to patients, capturing individual preferences around delivery and dosing schedules while setting a new standard in efficacy and safety. Specifically, with VYVGART, we have the first FcRn blocker on the market. The early launch dynamics show broad support and demand from physicians, patients, and payers. VYVGART has an individualized dosing approach based on treatment cycles.
We are also evaluating alternative dose schedules with ADAPT NXT for patients who may benefit from more continuous dosing. This allows us to further individualize our approach in reaching GMG patients. We showed today that we have a subQ product with a consistent efficacy and safety profile. Patients can choose the delivery option they prefer and not have to sacrifice response in doing so. We are investing in the future delivery vehicles and formulations. Whether it's a prefilled syringe or an auto-injector, we know that we cannot stop innovating if we want to continue to reach more patients. I mentioned at the start that with these data, we have passed our first hurdle in bringing a subQ option to GMG patients. We have also passed a hurdle as we look ahead to our broader efgartigimod pipeline.
We hope to leverage subQ efgartigimod across multiple indications and franchises, allowing us to bring optionality to more patient communities within hematology, dermatology, or kidney disease.
This is our long-term vision to bring efgartigimod to as many autoimmune patients worldwide, and we took an important step forward today. With that, I will turn the call over for your questions. Operator?
At this time, I would like to remind everyone, in order to ask a question, press star then the number one on your telephone keypad. We'll pause for just a moment to compile the Q&A roster. Your first question comes from the line of Derek DeSilva from Wells Fargo. Your line is open.
Hey, good morning, guys, and thanks for taking the questions, and congrats on the data. Just two quick ones from us. Maybe first, can you just kind of expand on the MG or the worsening MG symptoms and I guess maybe your thoughts on why we didn't see it in the IV treatment arm? Then, Keith, I just wanna kinda get your thoughts in terms of the split between your view on the usage of subQ versus IV, maybe not just in MG, but kinda broadly across all the indications. Like, what do you think the utilization rates of those two presentations will be? Thanks.
Thank you, Derek. Let me start with question number one. That's a very simple one. The trial design is such that you can only give the patient one treatment cycle. So at the end of the 10-week period, it's natural that you see worsening of symptoms. It is basically at the physician discretion whether or not to report such worsening. So I would like to draw your attention to the fact these are really small numbers and nothing out of, you know, what is to be expected. Keith, up to you for question number two.
Thanks for the question, Derek. We have done market research with KOLs that treat GMG. In that patient population, we've heard that they believe the split will be somewhere around 70% subQ, 30% IV. Certainly they're pleased to have both options available for their patients, but also it can affect payers and out-of-pocket expense for patients. When it comes to the other indications, we have not done the market research on that yet, so it would be inappropriate for me to comment on that. Remember, though, we are using both subcutaneous and IV formulations in our ITP study, and we use subcutaneous in pemphigus and in CIDP.
Great. Thanks, guys. Congrats on the data.
Your next question comes from the line of Akash Tewari from Jefferies. Your line is open.
Hey, guys. HYQVIA was associated with increased ADAs in chronically dosed patients. Have you seen any ADAs in your study, either in the subQ or the IV arm? And if so, do they have an impact on efficacy? In your phase III ADAPT trial, it looks like worsening MG was also reported as an AE. What were the overall rates of MG worsening in ADAPT? What time point did they occur, and how did that compare with the study that you reported today? Thank you.
Yeah. Thank you, Akash. On the topic of ADA, these are top-line data. We don't have the ADA data yet of this specific study. We will of course report this data later in the year at a medical conference. Just remember, we have a significant data set now for ADA of efgartigimod across healthy volunteers and patients, and there is not such a thing like an ADA signal, nor in healthy volunteers, nor in patients. We anticipate this is going to be exactly the same case in ADAPT. Whether you look at the REGAIN study, the ADAPT study, this study, you do see of course MG worsening towards the end of a treatment cycle or between the treatments.
I do not know the number by heart from the ADAPT study, but it was clearly there both in placebo and active, so this is nothing out of the ordinary. Thanks for the question.
Your next question comes from the line of Tazeen Ahmad from Bank of America. Your line is open.
Hi. Good morning, and thank you for taking my questions. Congrats on the great data. I was just curious as to what you think the results of this study mean on a go-forward basis, not only for the additional indications that you're looking at, but does this open up the potential of looking at other indications that you might not have been sure about before? I have a follow-up. Thanks.
Yeah. Thank you for the question, Tazeen. Thanks for being with us today. This is a very powerful subQ product execution, right? I mean, if you look at the PD profile, if you look at the efficacy safety profile. Maybe, Keith, you want to expand a little bit on, you know, how this is opening up our options going forward in building out the efgartigimod franchise.
Yeah, happy to do so, Tim. Tazeen, what this gives is the optionality for patients that do not wanna go into the infusion center. Maybe it's from a convenience point of view, maybe it's from a location point of view. You also have patients that are not gonna be able to take the time out of their day to go in for a one-hour infusion. Now with a self-injectable, the potential to have a self-injectable that takes a minute to two minutes to inject, we really think it's gonna broaden the overall number of patients that we're gonna be able to serve, not just in GMG, but hopefully in the potential other indications of which we're studying.
As far as does it open us up to even further, remember, we've shared with you 10 indications that we're already studying efgartigimod in, but we have publicly said we plan to start working in up to 15 by 2025.
Okay. Thank you. Keith, maybe can you elaborate on how reimbursement for physicians could influence whether they choose to recommend the IV or subQ to their patient population?
Yeah, I mean, really, if we take a look at a Medicare setting, we would be looking at the IV given in the presence of a healthcare professional, and that would be billed under Medicare Part B. Whereas a lot of the subQ, if they're going to administer at home, what we hope to have is an option for the subQ where it can be given either in the presence of a healthcare professional, like we did in the main part of the study, or self-injected at home, like we're doing in the open-label extension, very similar in the CIDP study. That would open up the ability for the subQ to either go through a specialty pharmacy and be billed under Part D, or they could get it in the presence of a healthcare professional and under Part B.
What this has is it potentially has an impact on patients' out-of-pocket expense, and that's why in any situation I would encourage verification of benefits before there's a decision made on the location of where the patient and what formulation the patient would be treated with.
Okay, thank you.
Your next question comes from the line of Joon Lee from Truist Securities. Your line is open.
Hi. Thanks for taking our questions, and congrats on the positive data. How explicit was the FDA that non-inferiority on IgG reduction a week after the last dose was the approvable endpoint, and what was the margin for non-inferiority? I have a follow-up.
Thank you, Joon, thanks for being with us today. The non-inferiority margin was 10%. As we said before, that's a typical margin, you know, utilized by the FDA. 10% was the margin. As we discussed previously, yes, we did, of course, meet with the FDA ahead of this study, triangulating expectations and getting buy-in on this rationale, which we observed. Ultimately, of course, everything depends on the data and is subject to review.
Got it. I understand that for U.S. and Japan, this is a separate BLA submission, so you will do that by year-end. For the E.U., is this also a separate submission, or is this more of a line extension? If it's the latter, would it be possible to see subQ formulation commercially in the E.U. ahead of U.S. and Japan?
Keith, do you want to take this question, please?
Yeah, happy to, Tim. You're correct. In the U.S. and in Japan, this will be a separate filing and a separate BLA. In Europe, this will be a line extension. It will be the same brand as VYVGART. It would just be the subQ formulation that's available. Still, even with that, I wouldn't expect that you would see it available prior to it being available in the U.S. Remember that the big thing is going to be not just getting the regulatory approval, but then it would be the negotiation process on a country-by-country basis across Europe, which, as I've shared before, could take anywhere from 12 months to three years.
Thank you, and congrats on the data again.
Thank you.
Thank you.
Your next question comes from the line of Matthew Harrison from Morgan Stanley. Your line is open.
Great. Good morning. Thanks for taking the questions. I guess first, can you just comment on any other factors beyond the safety database which may impact the filing timeline or any other things that you need to be doing behind the scenes? Secondly, could you just comment on the scope of the ISRs and how they look versus other Halozyme products? Thanks.
Thank you, Matthew. Two excellent questions. Really the rate-limiting factors on the trajectory to BLA submission is the collection and reporting of the safety data. We said in previous calls publicly that, you know, all subjects which we need to have on drug are on drug, so it's now just a waiting game, you know, collecting sufficient exposure data for these patients to then collect, process the data and submit them. That's really the rate-limiting factors. There are, of course, efficiencies between the IV BLA and the subQ BLA when it comes to, for example, the preclinical section or the CMC section, because the manufacturing process is basically identical except for the final dilution step in case you want to go to an IV product. When it comes to the ISRs, it's very straightforward.
21 cases, 18 were mild. Just a typical redness, swelling, itching, it resolves spontaneously. You see also a decrease over time in these patients. I would say this is largely in line with, you know, other Halozyme-equipped products or even more broadly, you know, subQ-delivered biologics in general. Thanks for the question.
Your next question comes from the line of Yatin Suneja from Guggenheim. Your line is open.
Hey, guys. This is Evan on for Yatin. Congrats on the data, and thanks for taking our questions. One quick one for us. Can you comment on the heterogeneity you've seen in IgG responses with the subQ formulation? Is there anything that can reliably predict the trajectory of the IgG curves? And, you know, as a follow-up, do you see any major differences in these curves between the seronegative and seropositive patients? Thank you.
Thank you for the question. The IgG reduction curve is very predictable, as we have basically shown for the primary endpoint slide number eight. Actually your curve is identical to the IV curve. The dose and the time will perfectly predict what your IgG level reduction is gonna look like. The curves are perfectly superimposed. We also said in the prepared notes that the autoantibody titer is following exactly the same curve as these total IgG curves, and I can confirm to you that in the seronegative patients, total IgGs behave exactly the way these curves are predicting. Thanks for the question.
Your next question comes from the line of Allison Bratzel from Piper Sandler. Your line is open.
Hi, good morning. Thank you for taking my questions. First, just a clarification on the AE of MG worsening. Was that a protocol-defined adverse event, for example, defined by a certain level of worsening on MG ADL or earliest use of rescue therapy? Or was this really just an AE that was up to the investigator's discretion?
Yeah, it's very much the second one. I invite you to look at the slide number 10, which shows you the ADL and the QMG scores. You basically see that, you know, for both arms, these curves behave identically the same. It's basically at the discretion of the investigator to call out MG worsening. That's what happened in this small number of patients in the subQ arm compared to the IV arm. Thanks for the question.
Okay. Maybe just one other on the injection site reactions. I guess, was there a relationship between the speed or time of administration and the type or severity of ISRs? I think you've kind of talked about a learning curve on the injection technique. Maybe if you could elaborate on that a little bit, were most ISRs reported in the first couple weeks of dosing, and how will that evolve as we move to self-ad-administered subQ efgartigimod?
Two things here in your question, which is very interesting. Like all the published data you can find on subQ-delivered biologics and including the Halozyme-equipped biologics, you do see that learning curve. That's interesting. You do see these injection site reactions diminish over time. Actually, they disappear. Then the question is, we had the same question internally. Is it a learning curve, or is there something else happening? We just do not know the answer yet. Stay tuned, I would say, because the open label extension study is going to be very interesting. While it was an HCP administering the drug in this randomized controlled trial, in the open label extension, the vast majority of patients opted for the training to learn how to self-administer.
It's going to be interesting to observe, you know, whether a self-administration goes hand-in-hand with fewer ISRs or just more ISRs, we don't know yet. Stay tuned.
Thank you.
Your next question comes from the line of Jason Butler from JMP Securities. Your line is open.
Hi. Thanks for taking the question. Maybe a follow-up on the last one. From the patients that had an ISR in the first cycle, any data so far to suggest whether or not they're more likely to have another adverse event with subsequent cycles? I guess similarly on efficacy, do you have data yet that supports that similar to the IV, that there’s a robust and durable effect with retreatment with the subQ? Thanks.
Yeah. Two great questions. On your second question, I can confirm to you, although we need to wait for the final data, that people then who roll over to the open label extension receiving the second cycle, I mean, they perfectly respond the way you would expect them to respond, as we have seen for IV. More data to come, but no surprise there, I would say. There's no real pattern for the injection site reactions. It's difficult to predict, you know, who is going to have an injection site reaction, how long it's gonna last, and, you know, whether that's gonna pop up the next time. General trends are they gradually disappear over time. Again, guys, I mean, 18 out of 21 are just mild. There was no need for intervention or the special care.
They did basically come and go in a transient fashion with no extra care. This is very much in line with what we could find back in literature overall.
Great. Thanks for taking the question. Congrats on the results.
Thank you.
Your next question comes from the line of Danielle Brill from Raymond James. Your line is open.
Hi. Hi, guys. Good morning. Congrats on the data, and thanks for the question. Just a quick one from me and sort of a follow-up to the last. In the OLE, I'm curious how frequent are you dosing? Do you still have the same 50-day time period between treatment cycles? And are you noticing any trends in the OLE where patients may require treatment sooner? Thank you.
Thank you, Danielle, and thank you for your question. In the open-label extension, we allow retreatment based on a clinical evaluation, so there's no fixed forced dosing, you know, unlike in that's where we initially wanted to establish the real durability of the effect before then we allowed re-dosing in the open-label extension to study. Here, basically, you use the drug based on clinical evaluation. You can trigger your next cycle based on clinical need. Stay tuned, you know, we're still collecting these data. We will report on these data going forward at a clinical conference. It's too early to comment on it, but so far, we see behavior, you know, perfectly in line with expectations.
Great. Thank you, Tim.
Thank you.
Your next question comes from the line of Emily Field from Barclays. Your line is open.
Hi. Thanks for taking my question, and congrats again on the data. A couple quick ones from me. Just, you know, given that you're also pursuing both formulations in ITP, given the staggered timing of the readouts, if you could just confirm the filing strategy across both those formulations and also whether differential branding will be pursued. I know you said you're not going to, you know, make commentary on pricing between VYVGART and subcutaneous efgartigimod in MG today. You know, perhaps if you could provide a theoretical framework around why one formulation may be worth pricing at a premium to the other. Thank you.
Now I'm going to hand over question two to Keith on ITP. We continue to inform you that the FDA told us they need two independent phase III trials, so registration trials for submission. That's what we're doing. We adapted in full COVID time to a second study where we used a Halozyme-equipped subQ products to maximize flexibility. Your question is topic of an upcoming FDA interaction, where we will basically continue to calibrate expectations on how these two studies jointly can qualify for a submission. Maybe, Keith, you want to comment on the pricing flexibility which you have with the subQ product versus IV?
Yeah, happy to do so, Tim. Thanks for the question. The benefit of this being a combination product with the Halozyme ENHANZE, it makes it a completely separate BLA, and that allows us to have the potential to price at a different price per milligram. We don't have to have it similar to that of the IV. Now, you ask why, what could lead to, you know, having either a higher price or a lower price. We're gonna continue to study this. I could give you an example and say, in a subcutaneous product that you administer at home, you could have a superior price, but have a lower cost to the overall to the insurance company because they're not paying for a visit or the infusion materials, the nursing time and such.
you know, there's a lot of factors to take into consideration, but we have not made any decision on price, whether we will be at parity, higher or lower at this point.
Great. Thank you.
Your next question comes from the line of Joel Beatty from Baird. Your line is open.
Hi. Thanks for taking the questions and congrats on the data. The first question is regarding the MG worsening that was reported as AEs. Are you able to look at the clinical efficacy measures that were captured and see whether there were any signals of MG worsening in the subQ arm compared to IV? The averages in the presentation look great, but curious about signals of worsening. Then second question is on the injection site reactions. It looks great that all but two were transient and resolved without treatment. What treatments were used in those two?
That's a great question. Wim, if you're on the line, I will refer to you for what medication was used for these two cases. First, on your first question, it's an excellent question, and it's the first thing we did. Actually, you do not see any difference between the two arms when you objectively look at changes in an ADL or a QMG score when your IgG curves return to baseline. They nicely track together, and therefore, we believe it was a difference in preference of the investigators to report or not the MG worsening. Wim, can you comment on the type of medication which was used in these few cases?
Yes. Can you hear me?
Yes, Wim, we can hear you.
Okay, great. You refer to the cases that were called out as myasthenia worsening, right? Well, there was
No, Wim. It's the injection site reactions.
Okay. Oh, okay, sorry. The injection site reactions were treated with very simple, local, these were the grade twos. The grade ones didn't need any treatment. In the grade twos, we had, local steroids. An antihistamine was given. This is the type of treatment, and they resolved.
Thank you, Wim. Thank you.
Thank you.
Your next question comes from the line of Emmanuel Papadakis from Deutsche Bank. Your line is open.
Hello, thank you. A couple of quick ones from us, please. Is there any additional color you could give us on the MG launch so far on the patient numbers and how representative are the IQVIA prescription data now, and will that improve over time? And just quick follow-up, how fast do you expect the switching from IV to subcut to occur? Thank you.
Yeah, but-
Quick follow-up after that.
Thank you for the question. Keith, I will hand over to you for the switching question. On the first question, we can be formal. Let's all wait for the Q1 earnings call for that extra color you're all waiting for. Give it a few more weeks, and then we will be ready to talk about it. Keith, do you want to give color on expectations around switching behavior from IV to subQ?
Yeah. I mean, right now we
Yeah, sure.
Right now, the only situation where we have is the patients that we took from the ADAPT OLE and allowed them to roll over into the subQ OLE. I will call out that not 100% of patients that were on the IV formulation chose to go into the subQ because, again, we have different preferences. As far as the speed of which an IV patient would roll over to subQ, we don't have that information at this point. I think it's gonna be on a patient-by-patient basis.
Thanks, Keith.
Thank you.
Your next question comes from the line of Charles Pitman-King from Redburn. Your line is open.
Thank you very much. Thanks for taking my questions, and congrats on the positive results. Yeah, two very quick ones from me. I was just wondering if you could elaborate on the triggered or expected milestones for the Halozyme collaboration as a result of this readout. Secondly, just on where, given the expected regulatory process, when might we expect a decision from you guys on the potential use of your PRV? Thanks very much.
Yeah, these are two quick questions indeed. There's no milestone associated with this data readout. The way you have to think about milestones and other payments to our partner, Halozyme, is in line with, you know, what is publicly known about their licensing deal. Our deal is not any different. Expect something around approval instead of, you know, readout. Secondly, the PRV is an important business decision which we will be taking later this year. Stay tuned. It is something, you know, which is on our plate. We have two very exciting options where we could apply the PRV. One would be to accelerate the subQ product to our MG market or to accelerate efgartigimod into, hopefully, its future CIDP market.
Stay tuned on that decision, and thank you for the question.
Amazing. Thank you.
There are no further questions at this time. This concludes today's conference call. Thank you for your participation. You may now disconnect.