Thank you. A press release with our First Quarter 2020 Business Update and Financial Results was issued earlier today and can be found on our website along with the presentation for today's webcast.

I'm joined on the call today by Tim Van Hauwermeiren, Chief Executive Officer; Keith Woods, Chief Operating Officer; and Eric Castaldi, Chief Financial Officer. 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 development, 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 will now turn the call over to Tim..

Thank you, Beth, and welcome everyone. I first want to wish you and your family as well during a time, when COVID-19 has affected all of our lives in a myriad of ways. Slide 3, here at argenx, we are committed to protecting and supporting our employees and the communities, where we live and work.

We have had a work-from-home mandate in place since March, except for certain essential roles like those in our labs. We continue to have all work-related global and domestic travels suspended.

Even with this travel restriction, we have continued to stay close to all of our stakeholders through virtual conferences and meetings, including the investment community, physicians, patients, patient advocacy organizations, and payer groups. We have also continued to work closely together as one team, despite being in different locations.

I'm very proud of the important progress, we've been able to make across the company since the start of the year.

This is in large part, due to the investment we have made in IT infrastructure to accommodate our global expansion over three continents, but also due to the hard work, dedication and flexibility of our teams, allowing for the seamless transition to conducting business virtually.

Even during a time, when a lot is uncertain, we are confident in the strong fundamentals of our business, including a differentiated antibody pipeline and a solid financial position that allows us to advance our growth and development strategy and ultimately deliver meaningful immunology innovations to patients who need them.

Moving on to the topics of our call slide 4. We have a focused agenda today. The primary goal of the call is to provide you with an overview of the impact of COVID-19 across our business and detail what we're doing to mitigate the situation. We will also update you on the development of ARGX-117, our complement inhibitors targeting C2.

We have delayed the start of our Phase 1 trial in healthy volunteers, but in the meantime have had the opportunity with one of our immunology innovation program collaborators to launch a first-in-human trial of ARGX-117 in COVID-19 patients.

There's a growing understanding of the role of complement system in driving severe respiratory symptoms, associated with the virus. We feel we are upholding our social contract to help tackle this global health crisis, while also gaining critical information about ARGX-117 during a time when it is difficult to enroll trials in healthy volunteers.

We also want to use this call to talk about the updated data presented this week on efgartigimod in our third beachhead indication pemphigus. Professor Matthias Goebeler, presented the detailed Phase 2 data at the Society for Investigative Dermatology Annual Meeting that is being held virtually.

The data showed a promising tolerability profile and speed at which efgartigimod can push patients into disease control and complete remission, when combined with suboptimal doses of prednisone. Later in the call, Keith is going to cover our ongoing preparations for our planned 2021 U.S.

commercial launch of efgartigimod in generalized myasthenia gravis. The last few months have encouraged us to look at our launch preparations with a new lens and we have scenario planning around the unknown and potentially longer-term effects of coronavirus infection. Eric will then walk through our financial results for the quarter.

With that, I'd like to update you on our ongoing programs. We have not passed any of our ongoing clinical trials and are diligently monitoring that our patients and physicians are taking appropriate measures to stay safe, while participating in the studies.

To enable patients in argenx's clinical trials to receive study drug with continuity, we have implemented telehealth and remote monitoring activities and more flexible dosing schedules into protocols where possible. On slide 5, ADAPT our Phase 3 trial of efgartigimod in gMG. That study remains on track.

I must pay tribute here to the hard work from our MG team. We enrolled this trial faster than anticipated which turned out to be an incredibly important milestone particularly in view of the current situation.

By the time the shelter-in-place restrictions went into effect, all 167 patients in ADAPT had already passed the eight-week time point for the analysis of the primary end point and the majority of patients had already rolled over into the open-label extension. As an update today, all patients have now completed the 26-week primary trial.

We will be reporting top line data mid this year, which sets us up to file a BLA before the end of 2020, assuming success and to launch in 2021 in the United States. Additionally, we are on track to file in Japan in 2021. We were very pleased with the high degree of rollover to the open-label extension study, which remains firmly on track.

We are working closely with our CRO and trial sites to facilitate patients staying on study. We are also incorporating some of the measures, I mentioned above, including remote monitoring and home infusions. Fortunately the MG-ADL assessment is one that can be accommodated remotely.

The primary goal of the OLE is to gather the necessary safety data for our BLA filing and we remain confident this will happen. Supply chain and manufacturing remain a crucial component of our clinical development and commercial launch planning. We have partnered with Lonza and Zephyr who have shown their strength through this crisis.

Our global supply chain of drug substance and drug products remains unaffected and on track to support the launch in 2021. Our pipeline overview slide is on slide 6.

Our trials of efgartigimod that have already initiated remain open including the Phase 3 ADVANCE trial evaluating IV efgartigimod in primary ITP, the Phase 2 ADHERE trial evaluating subcu efgartigimod in CIDP patients, and the 11 patients still on study in the Phase 2 trial evaluating IV efgartigimod in pemphigus.

We do expect recruitment rates for the ITP and CIDP trials to be slowed due to COVID-19. We will provide an update on any potentially revised time lines, as we have greater clarity, but it's currently too early to estimate the real effect.

We are fortunate in that we run global trials in North America, Europe and Japan, so we are not confined to one affected area for patient recruitment. We will use this to our advantage as best as we can in opening new sites. Importantly, we do not currently foresee a delay to the launch of new efgartigimod trials and our guidance remains intact.

Two additional ITP Phase 3 trials are on track to start before the end of the year, which we expect along with ADVANCE will support registration for efgartigimod in primary ITP assuming positive data.

These trials include the ADVANCE two confirmatory trial evaluating IV efgartigimod in approximately 50 primary ITP patients that is expected to start in the first half of 2020 and the ADVANCE subcu trial evaluating both IV and subcu maintenance efgartigimod that is expected to start in the second half of 2020.

The PV registration trial is on track to start by end of year. Our decision to move to Phase 3 was based on the strength of the data we saw in Phase 2, which I will walk through shortly. And finally for efgartigimod, we do still plan to announce our fifth indication this year.

Before moving on, I'd like to quickly touch on how our partners have handled ongoing clinical trials slide 7. Janssen has passed many trials globally due to COVID-19. At this time both CULMINATE and the triple combination trial of cusatuzumab in venetoclax and azacitidine are both paused for enrollment.

Additionally, Janssen has paused the launch of new studies of cusatuzumab. LEO Pharma has paused this trial of LP0145 and for the treatment of atopic dermatitis. This is the compound that was previously known as ARGX-112.

We cannot say today when or under what circumstances, the cusatuzumab trials or those in the hands of LEO will be up and running again. We will be sure to update our stakeholders once we know more. Enrollment remains open in AbbVie's Phase 1 trial of ABBV-151, which was previously ARGX-115. Now on to ARGX-117.

You will note that we did not start a Phase 1 trial in healthy volunteers in the first quarter. We felt it was not prudent to initiate this trial in the current environment given challenges with recruiting healthy volunteers.

We did start the Phase 1 dose-escalation trial in COVID-19 patients as I mentioned at the start of our call, and I'd like to walk you through the brief rationale for this shown on slide 8. First, it has been difficult -- a difficult few months to watch tragedy strike, the health care and broader communities.

When Professor Bart Lambrecht, our collaborator from VIB-Ghent University Hospital and the Belgian National Commissioner for the pandemic approached us about sponsoring a trial, we felt it was important and our duty to participate.

Second, we always base our development decisions on a strong biologic rationale and there is one with ARGX-117 targeting C2. The role of complement system is known in the activation of an inflammatory response that can lead to acute respiratory distress syndrome in coronavirus infections.

C2 sits at a junction of the classical and lectin pathways which are both implicated in the downstream inflammatory response. We will first conduct a dose-escalation study in patients in recovery from the coronavirus and then shift to dosing patients at risk of developing ARDS.

Through this first-in-human trial, we will also gain important data points about ARGX-117 including PK, PD safety and tolerability and possibly an optimal go-forward dose all of which can be part of our broader development strategy. We still intend to launch a Phase I trial of ARGX-117 in healthy volunteers before the end of 2020.

We then can move forward with our Phase II strategy in severe autoimmune disease, including our first planned indication multifocal motor neuropathy. Moving on to other news. As you saw in the press release from this morning, detailed data were presented this week from the adaptive Phase II trial of efgartigimod in pemphigus at the SID Annual Meeting.

The meeting changed to be virtual and our prerecorded oral presentation became available online yesterday. We are grateful to Professor Goebeler from University Hospital of Würzburg for his flexibility in presenting the data in this less-traditional format. Slide 9.

Recall, in designing this trial, we took a unique and adaptive approach to evaluate the potential of efgartigimod in pemphigus while adjusting in a single variable way the dose between 10 and 25 mg per kg, the dosing schedule and the dosing paradigm between monotherapy and combination therapy with corticosteroids.

We also assessed the ability to taper steroids once patients reach end of consolidation. The updated data shown this week are from a data cutoff of March 25, 2020 and included the below highlights that are also shown on Slide 10. 90% or 28 of 31 patients evaluable for efficacy achieved rapid disease control.

The median time to disease control for monotherapy and combination therapy was 15 and 20 days respectively. The majority of patients reached disease control after one or two infusions.

Complete clinical remission was observed in 70% or seven of the 10 patients receiving an optimized dosing regimen determined to be efgartigimod, dosed at least every two weeks in combination with oral prednisone at a dose of 0.25 to 0.5 mg per kg.

73% or 11 of the 15 patients receiving 25 mg per kg efgartigimod achieved end of consolidation including patients, who then successfully tapered their steroid dose and 11 patients are currently still on study.

We had an independent data monitoring committee that assessed the safety and tolerability profile of efgartigimod and they felt it was favorable. This is very consistent with what we have seen across all our efgartigimod trials.

Patients enrolled in the last cohort of the pemphigus trial will be receiving efgartigimod for up to 34 weeks, which is the longest treatment period to date, excluding open-label extension studies.

Taking these data together, we are confident that we have shown important proof-of-concept in our third beachhead indication and have gathered the necessary information to design a robust registration trial in PV. With that overview, I'll now turn the call over to Keith for a discussion of our commercial readiness..

Thank you, Tim and good morning everyone. As Tim noted, we are very excited to be nearing the topline data readout from our Phase III ADAPT study in gMG patients. This is a transformational moment for the company and will mark a shift towards our goal of being an integrated immunology company.

We built an innovative trial design for our Phase III ADAPT trial that we believe closely mirrors how physicians would use efgartigimod in practice.

As we scale up our commercial team in Boston and throughout the U.S., these data will provide us with the unique insights into patient management and how efgartigimod could integrate into the current MG treatment paradigm.

As you look on slide 11, right now if you look at the current MG treatment landscape, we believe we can play across the spectrum of patients from earlier in the treatment cycle to the more severe refractory patients. gMG first presents with ocular symptoms and patients receive acetylcholinesterase inhibitors or ACIs at diagnosis.

As symptoms become more generalized, physicians will move to steroids. But in order to taper steroids and reduce the significant side effect burden experienced by the patients, physicians will use broad-spectrum immunosuppressants, which can take time to kick in and come with their own set of side effects and risks.

Agents like IVIg, rituximab and Soliris are used later in the progression of the disease when earlier agents are no longer effective. Our goal for efgartigimod is to allow for earlier steroid tapering and to delay or even eliminate the need for broad immunosuppressants. Moving to slide 12.

If we take this positioning and look at the addressable market, we believe we can target about 30% of gMG patients in the U.S. or about 20,000 patients based on a U.S. MG patient population of 65,000 in the U.S. This would be all generalized MG patients who require treatment beyond steroids and ACIs.

To reach these patients and the 16,000 neurologists who treat them, we will start to build a sales force of approximately 70 representatives assuming positive data scenario.

We've already built a network of medical research liaisons who have been engaging with neurologists across the country for the past 18 months and have more recently built our thought leader liaison network. Moving to Japan, we believe there are about 20,000 patients that suffer from MG being treated with -- by 200 to 300 neurologists in Japan.

The concentrated nature of the MG market and the universal health care coverage make Japan a very appealing market for our second launch. The COVID-19 pandemic has not slowed our commercial readiness progress, but it has made us stop and consider the environment, into which we could be launching our drug into next year.

Our team has committed to preparing for all scenarios including a world that generally returns to normal where we can activate our sales force to be present in doctors' offices and hospitals; or a world that is in full shutdown after another outbreak where we have to launch through virtual and digital interactions only; and somewhere in between where we believe we have to embrace a new normal and rely more heavily on digital and virtual capabilities while still having the option to see customers in person.

We will be ready for any of these scenarios and have organized work streams across all key launch functions to consider the implications of this new normal. To wrap up and to reiterate Tim's earlier comments, our global supply chain remains on track for launch.

We are grateful to be working with Lonza and Zephyr for our global manufacturing and have witnessed the capabilities of both organizations to activate risk mitigation strategies where necessary. We also continue to prioritize the development of our subcutaneous efgartigimod products in MG to provide optionality for patients, physicians and payers.

We are planning to meet with the FDA this year on a potential bridging strategy and will communicate once we have a clear path forward. With that, I'd like to turn the call over to Eric for a review of our financial results..

Thanks, Keith. Slide 13 covers our first quarter 2020 operating results, which are detailed in today's press release and regulatory filings.

So as you can see on this slide total operating income reached €23.4 million for the first three months of 2020, a decrease from the same period in 2019 due to a milestone payment we received last year under the AbbVie collaboration agreement.

R&D expenses for the three months ended March 31, 2020 were €94.9 million compared to €34.8 million for the same period in 2019. SG&A expenses were €25 million for the first three months of 2020 compared to €11.3 million for the same period in 2019.

The increases in R&D and SG&A expenditures over the prior year have been driven by the progress made with our late-stage pipeline, including higher consulting and personnel expenses, higher clinical trial cost and manufacturing expenses and the recruitment of additional employees to support ongoing activities.

We expect operating expenses to continue to increase this year as we further advance our pipeline and prepare for future commercialization. For the first three months of 2020, financial income amounted to €1.7 million compared to €3.5 million for the same period in 2019.

Exchange gains totaled €20.8 million for the three months ended March 31, 2020 compared to €9.5 million for the same period in 2019. The total net loss for the three months ended March 31 2020 was €80 million compared to a total comprehensive profit of €6.7 million for the same period last year.

You will recall this profit was an outlier due again to the milestone payment we received last year from AbbVie that was mentioned previously. So we ended the first quarter of 2020 with €1.3 billion in cash, cash equivalents and current financial assets compared to €961.6 million for the same period in 2019. And I will now turn back the call to Tim..

Thank you, Eric. Slide 14. 2020 is off to a strong start and we expect to have an especially exciting year as we meet the top-line data readouts from our ADAPT trial and advance efgartigimod toward commercialization.

We continue to have strong fundamentals across our business, including our pipeline of late-stage product candidates with efgartigimod being evaluated in four indications and cusatuzumab in AML and high-risk MDS as well as our growing pipeline of early-stage candidates with ARGX-117, ARGX-118 and ARGX-119 this year.

We continue to expect up to five Phase III trials and seven earlier-stage clinical trials to be ongoing this year in indications that are synergistic to our growing commercial infrastructure. We are very enthusiastic about the prospects for efgartigimod in MG and are preparing for success by growing our commercial team.

And as Eric mentioned, we are grateful to have a strong cash position during this time of uncertainty thanks to the ongoing support of our shareholders.

Before turning the call over to your questions, I would really like to take the time to acknowledge and applaud those on the frontline fighting this global pandemic in particular those nurses and physicians providing direct care for COVID-19 patients including some of our own employees who have devoted their own time to this cause.

With that, I will now turn the call over to the operator for your questions..

Thank you. [Operator Instructions] We will now be taking our first question from the line of Ted Tenthoff from Piper Sandler. Please go ahead. Your line is open. .

Excellent. Thank you so much and great update. Glad to hear everyone is doing well. Just with respect to the upcoming myasthenia gravis study, Keith I appreciate all the commentary on potential for buildout. How quickly would you guys be able to file the BLA? And what would be your plans for Europe? Thank you so much..

Thank you, Ted and good to hear the voice. Good to hear and apparently everything is fine. So with the Phase III data readouts planned for mid-2020 what we say that is that we're on track to file the BLA by the end of the year. That basically puts us in position for a launch in 2021.

How long exactly the review procedure with the FDA will take? We do not know. But I would like to call out our earlier announcement that actually we did receive a fast track by the FDA..

Yes, congratulations on that. And then what would be plans for Europe? Is that something you would consider taking on yourself? I appreciate the commentary on Japan. But would Europe be a potential partnering opportunity, or would you expect to launch there yourselves as well? Thanks so much..

Yes. What we said in public that is that priority number one is going to be the U.S. Priority number two will be Japan. And then we have declared our intention to be active in Europe as a third priority where we called out the big five as the countries where we may become active. But that is our third priority..

Excellent. Thanks so much and beloved..

Thank you, Ted..

We will now be taking our next question from the line of Christopher Marai from Nomura. Please go ahead. Your line is open. .

Good morning. Thank you for taking the question. I was wondering first maybe for Keith, if you could describe your plans for the launch with respect to potentially launching this drug in a virtual mode? And then secondarily how ready you are for initiation of home infusions.

How much experience do the KOLs have with that right now? And how much do you expect docs to be able to adopt home infusions at the early part of the launch? And I have a follow-up. Thank you. .

Yes. Chris, thank you for the question. So as I mentioned in the prepared statements we're preparing for all scenarios across our launch work streams. Obviously this -- it's much more difficult to launch when you can't schedule in person interactions with the physicians and the patients and the payer groups.

However, we are managing to work with all three of those groups even in this current situation. We're not alone in this scenario. As you know many other -- every other company is in this scenario.

And what I can say is maybe we're a little bit lucky that we're not launching this year when COVID-19 hit us for the first time and we were into full launch because we still have time to learn to plan and to adapt.

And that's basically what we're doing is looking directly to more virtual and digital approaches while at the same time still trying to be innovative in our approach..

Okay.

And then just with respect to the home infusion how prepared are you? And how much experience do physicians have with your drug and home infusion dosage?.

So one of the steps that we have taken in clinical trials has been to make the availability of home infusion possible for some of our sites. So we have started to convert over to that in our clinical trials. We already know that many gMG patients that receive IVIg will get that from a route of home infusion.

So it is something that we were already exploring and speaking with the home infusion companies in preparation for launch. So I think to be able to adapt to this as a location for treatment should not be a challenge for us..

Okay. And then just one last one, with respect to potential for less frequent dosing compliance-type issues that could arise whether it's in a trial or otherwise. Obviously in MG the antibody is causal to the disease.

But I was wondering if you could frame and maybe Keith can frame this from a market access perspective or a market perspective compliance perspective how often you expect patients to be receiving doses and the potential for them to delay doses from what's happened sort of in the trial setting.

How are you thinking about that? How are maybe some KOLs thinking about that in practice? Thank you..

Yes. Well I guess first of all in regard to the dosing, I don't want to speculate. I'm looking forward to seeing the Phase III data. I do remind you Chris as you know that in the Phase II data 75% of the patients had a response of at least six weeks. And in reality the majority of those patients were still in response at week 11.

So we'll still need to see the data. When it comes to patients being compliant with their medication; when they have a customized dosing schedule this is, how many patients are currently being treated.

So I would call the example to chronic IVIg whereas if you look at patients with MG that are treated with IVIg, they are not all on an identical dosing schedule. Basically these MG patients can feel the beginning of the return to symptoms and then they are going to want to get their medication.

So I believe that how we've set this up is going to allow patients to be customized. But at the same time they will want to be treated because they want to live symptom-free life..

Thank you..

We will now be taking our next question from Tiago Fauth from Crédit Suisse. Please go ahead. Your line is now open. .

Hey guys, thanks for taking the question. I had a follow-up on enhanced formulation. I'm curious, if you generated additional in-patient data to support every-other-week subcu injection.

How does that stack up against the model data? And just a quick follow-up on pemphigus, if you could just recap the target population positioning for efgartigimod relative to rituximab and the commercial opportunity that we have in that indication? Thanks a lot..

Thank you Tiago for the question. You know that we did initiate the CIDP study using the efgartigimod subcu product. And initially that is going to be based on a weekly dosing Tiago. So we haven't made it yet to an every-other-week dosing schedule. That remains to be explored in the future of that trial or other trials.

When it comes to pemphigus' competitive positioning you need to know that pemphigus is a very bad autoimmune disease with too few tools in the toolbox. So today people actually have not much more than high-dose corticosteroids maybe some of the IFTs and then rituximab.

Antibody cusatuzumab of course is a major innovation in this space which is stuff for innovation. It's not a solution for all. We basically see a relatively slow onset of action. Patients need to be managed with high doses of corticosteroids until the effect of rituximab kicks in. And then we also see a pretty high relapse rate.

So from a competitive positioning point of view, we look at the world in terms of more tools in the toolbox not less. And I think efgartigimod is hopefully going to build its own unique proposition based on its rapidity of onset -- of action and then secondly the ability to taper steroids very fast.

So I think that's very complementary to for example a rituximab positioning..

Got it, thank you very much on the color..

Thank you. .

We will now be taking our next question from the line of Graig Suvannavejh from Goldman Sachs. Please go ahead. Your line is now open..

Great, thank you. Good morning. Good afternoon. I've got two questions. And thank you for taking them. One, I'm curious about 117. And I saw you're doing, COVID-19. When might data be initially available? I know its early days.

But what are you thinking about that? And then, a quick follow-up there is what would be the plan if you actually had positive data? And would that be a combination-study setting? Just how are you thinking about the potential further development plan there? And then, just one on the model, I know that the guidance is on OpEx to continue growing.

I'm just wondering if there's any lumpiness over the balance of the year in terms of SG&A or R&D, as we look out throughout the year. Thanks..

Thank you, Graig. And I will give the second question to Eric, in a minute. So, concerning ARGX-117 in COVID-19, this team has been pulling the trial together at record speed in very close partnership and collaboration with the regulators, the Belgian FDA and our academic partners.

So the deal, I think is that, when we have positive data, we will embark in a Phase II trial to build on these positive data. When exactly we're going to release data remains to be seen. Here in Belgium for the moment, the COVID-19 epidemic really cooled off. We are coming gradually out of the lockdown.

And experts believe that, it's going to be a balancing act between relaxing the measures and seeing again an increase of COVID-19 patients. So it will depend a little bit on how this pandemic is going to evolve and how fast how many patients, we can actually get on study.

And Eric I would like to refer to you for the second part of the question regarding R&D and SG&A expenses..

Absolutely, yeah, thank you, Tim. So Graig you will see to -- sorry you will continue to see our ambition levels going up as we advance the pipeline. The additional registrational trials we have with efgartigimod, as we start the clinical development with earlier assets also. And don't forget also the funding of 40% of the cusatuzumab development.

So all this will come with additional spend so definitely the burn rate is going to increase substantially..

Thank you..

We will now be taking our next question from the line of Akash Tewari from Wolfe Research. Please go ahead. Your line is now open..

Hey guys. So looking at your Phase II MG data, it seems like the MG-ADL drop, didn't plateau after your four doses. In fact if you kept dosing it felt like you may have been able to drop it a few more points.

Can you go over biologically? What's going on in these symptomatic patients? And what does that mean for your ability to maybe space out the dosing of a long-term extension or get patients into a long-term remission? Additionally, given you're enrolling a more moderate to severe population in the Phase III study, is there any reason to believe an FcRn, wouldn't show similar efficacy to a C5 inhibitor in this type of severe refractory population? Looking back at the C5 studies, it didn't necessarily seem like a higher MG-ADL score at baseline, led to a greater drop in corresponding scores at the week four end-point.

So I would be curious to get any color on that. Thanks..

Thank you, Akash for these questions. So, the way we configured the dosing schedule for MG in Phase II is basically on the PD curves or the total IgG curves. What you get to see in the Phase II publication of course is the total curve showing the means for the population, we tested not the individual patient curves.

So we have these individual patient curves. And we feel comfortable to basically see that after the last weekly infusion you max out on your PD effects, that is in sync, by the way with the Phase I data, where we played around with dose and dosing frequencies.

So we think we have maximized the IgG reduction, through the current block of four weekly infusions. Your question on C5 is an interesting one. And actually there is no scientific or biologic rationale, why an FcRn blocker would not be able to play in a severe and refractory patient population.

We all know that complement, recruitment is just one of the three pathogenic modes of action, of these pathogenic autoantibodies.

And actually we expected by removing these autoantibodies, we should at least have the same effect as a complement blocker, potentially a battery effect because we also take care of receptor blockade, and receptor cross-linking and internalization-reducing signaling. And we agree with you.

There is no real correlation from the data we have or the data we have seen between a disease score. And the delta you can get in terms of ADL or QMG. So I think the jury is out there..

Thanks so much..

We will now be taking our next question from the line of Derek Archila from Stifel. Please go ahead. Your line is now open..

Hi, guys and thanks for taking the question. Congrats on all the progress. So, just a couple of quick questions on MG and one just an update on pemphigus' history. So on MG, can you just provide us what the run-in sort of potential of the Phase 2 study for the patients when they were on standard of care? That's a question that you frequently get.

And then secondly in the Phase 3 results how much information will we actually get on re-treatment of the active arm?.

So thank you for the questions Derek. I don't know by heart the run-in period for the patients in the Phase 2. I think that's disclosed in the publication. I think we are expecting the standard washout periods. And I do remember that for IgG-based medication that was six months.

What we also said in public is that on average a lot of the patients or all of the patients which came in into study had been for substantially longer periods on stable dose of background medication than the periods which we were requiring according to protocol.

So, we do know they were on stable dose, and therefore we do not believe that that background medication or changes in the background medication may have influenced the Phase 2 data. In terms of retreatment information, I think we still -- thinking internally on the specifics of the top line Phase 3 data communication.

Expect us to share primary end point analysis, assessment of safety and tolerability, and possibly some trends on some of the secondary end points..

Got it. And then a quick one on pemphigus. I just wanted to know, as you think about the Phase 3 trial, is this something that you're going to bring the IV forward, or is this an opportunity to also bring in the enhanced subcu version into that trial? Thank you..

Thank you for that question, Derek. So we will be giving more specifics on the Phase 3 trial design later in the year, when we disclose the Phase 3 trial design in its totality. We typically like to do that in the context of a KOL event, and we're currently thinking about how we could organize that in today's virtual world. So stay tuned.

The details of the Phase 3 will be the disclosed second half of the year..

Excellent. Congrats on the progress and stay safe..

Thank you, Derek..

We will now be taking our next question from the line of Matthew Harrison from Morgan Stanley. Please go ahead. Your line is now open..

Thank you. This is Max Skor on for Matthew Harrison. Could you comment on the evolving competitive anti-FcRn landscape, specifically Alexion's decision to advance only the subcu formulation? And also do you have an update on the subcu bridging study and time line for meeting with the FDA? Thank you very much..

So concerning the subcu bridging study, what we said in public is that we have an FDA meeting on our to-do list for this year, where we actually will discuss our proposal and hopefully come to an agreement. What we said is that when we will have had that meeting, we will have received the written minutes.

We will communicate to the stakeholders on the outcome of that meeting. Now in terms of the evolving competitive landscape, it is true that we see some shifts in that competitive landscape with the dropout of the Affibody molecule and some delays in some of the others -- competing trials. But I think the big picture Matthew is still very much intact.

I think there are a few players, which have shown Phase 2 efficacy data, and therefore we only have to navigate so far based on Phase 1 PD data and safety data. But I think we continue to be in an outstanding position, when it comes to differentiation.

I think from an efficacy point of view, in our MG ITP and PV trials, we've put the efficacy bar very high. On the safety side of things it's clear that not all accidents are made equal. I think we have a distinctly different and clean profile.

And I think on the convenience dimension, I think it is important to mention that we have a winning IV execution, and probably also winning subcu execution thanks to the Halozyme ENHANZE exclusive license. Mind you that we are also differentiating when it comes to trial design, and the way we work with patients.

I think the ADAPT trial design is unique. It's innovative. And if it is successful, we will be actually shaping up the market by what we are doing in the ADAPT study. And then of course, we also try to stay very close to the MG patient community through initiatives like MyRealWorld MG.

So I think in our efforts to differentiate, we've gone way beyond, I think a winning molecular design into clinical trial and patient-centricity thinking..

Thank you..

We will now be taking our next question from the line of Yaron Werber from Cowen. Please go ahead. Your line is now open..

Hi, guys. This is Brendan on for Yaron. Thanks very much for taking the question. And congrats on another great progress today.

I actually just really quickly wanted to first ask -- actually looking ahead to the ITP trial, can you just really quickly remind us what the timing of a filing there would be? Would you look to file after the first and second confirmatory trials' readout, or would you wait for the full results of the subcu trial as well? Like are you thinking to launch right out of the gate in ITP with that subcu maintenance regimen? And then I have a follow-up.

Thanks..

Thanks, Yaron.

Maybe Keith you want to take the first question on the ITP trial strategy?.

Sure. Happy to do so Tim. So first of all, Brendan as far as the timing on the ITP trials Tim did share in the prepared statements that enrollment has slowed a bit due to COVID-19. So we are not in a position to provide firm guidance on what that timing would be. We don't know if we'll see a relapse of COVID-19 that could again slow trial enrollment.

So not ready to make a firm statement on that. In regard to the IV to subcu remember this is where we will use a subcu maintenance dose, which is a much smaller dose of efgartigimod. That third ITP trial, we will put patients in we will induce them with 10 milligram per kilogram IV and get them into response and then the idea is to maintain them.

We believe that although that trial is starting later than our first two ITP trials, it will be run concomitantly -- so concurrently. So there's a possibility that they could all finish up around a similar time.

But to answer the question direct if we find that the subcu trial is not ready and we're ready to file with the IV, we will move forward with the first two and continue to subcu. .

Got it. Great. That's super helpful. And then actually just one really quickly on the PV trial readout yesterday. It's obviously pretty exciting the possibility of this steroid-sparing effect.

I was wondering I know you guys had some really detailed information on a few of the patients in the deck, are we going to maybe get a little bit more granularity on the extent to which individual patients are able to taper off steroids? And I guess, how you're kind of thinking about showing that in a concrete way maybe moving forward.

Thanks very much..

So thanks. We already gave quite a little -- quite a bit of granularity I think in the Phase II presentation on the individual patients when you look at the individual PDI scores and then the three patient anecdotes, which I think are pretty representative for what we are seeing in the trial.

I think we had quite a few patients, which actually managed to taper off steroids in a pretty impressive fashion. I think we had in total 13 patients out of cohort three and four where we successfully and aggressively tapered the steroids.

I think you will find more detail on this in a publication, which we would plan to release the full details of the Phase II study. But I think the three patient anecdotes which we show you are pretty representative for what we have seen in cohorts 3 and cohort 4..

Okay. Great. Thanks very much, guys..

Thank you..

We will now be taking our next question from the line of James Gordon from JPMorgan. Please go ahead. Your line is now open..

Hello. James Gordon from JPMorgan. Thanks for taking the question. First one was just to echo MG ahead of the ADAPT results. Just generally when we go from Phase II to Phase III you often get some efficacy deterioration maybe because of less rigorous patient selection.

And then we've got some helpful data about what the Phase II would look like when you did a six-week responder. But you're doing a four-week responder which may be filtering less noise.

So just when planning the trial how much weakening were you allowing for? How much buffer have you got? And what's sort of the minimum you need to get over the line would be the first question please..

Yes. So when we were moving from Phase II to Phase III, James of course we had an opportunity to test-drive the primary end point definition we would use in the ADAPT study on the Phase II patient population.

We feel comfortable with the responder definition of seeing an at least two-point improvement on the ADL score in at least four subsequent visits in the first eight weeks. I think the separation from placebo is still strong.

I think we have been saying in public that if you would apply that end point on the Phase II study you would still have a 75% response in the efgartigimod arm and a 33% response in the placebo arm.

Our statisticians had the benefit of looking in detail at this data, but also the placebo response in the REGAIN study and some of the other small Phase II proof-of-concept studies. So whilst we haven't been public on the exact powering of the study, I can assure you that we took a pretty conservative approach to the powering of the study. .

Thank you. And then second question please. Is just about recruitment in the ADHERE studies in CIDP.

Can you talk about how many patients you are planning to recruit into the study so far?.

We're not public on the number, but the study is open as we said in the release. We did not pass the study. The study is openly screening patients. The first patient entered the study already some time ago and we will continue to screen patients and work towards the 30-patient go/no-go decision point.

We always said that this study would run relatively slowly because of the three filters, which we installed at the start of the study for patients to go through into Part D. But so far I think that study is coming nicely out of the gate..

Thank you..

We will now be taking our next question from Jason Butler from JMP Securities. Please go ahead. Your line is now open..

Hi. Thanks for taking the questions. First one for Keith.

Obviously, when you look forward to the launch and you think about potential virtual strategies, are there things that you're doing now with your MSLs that you can build into your education strategies awareness strategies to gain some experience with virtual tools ahead of a potential launch? And then second question, Tim in addition to the work you're doing with 117 in COVID-19, are you doing any additional work to leverage the platform for antiviral antibodies? There was some work published recently on camelid antibodies in coronaviruses.

So just wondering if there's any application for your simple platform here? Thanks..

Great. Thanks for the question Jason. In regard to the launch and having to launch potentially in a combination of virtual and in-person, as I said we are learning a great deal right now and fortunate that we're not launching at this time. However, we are very active with the medical community.

You mentioned our MRLs and the learning that is taking place right now. Our MRLs are still as well as our thought leader liaisons are active with the KOLs in MG.

And not only are we able to continue to discuss with them treatment disease those that are participating in our trial in regard to our trial, but we're also getting an understanding from them of what they believe the new normal is going to look like in an institution-by-institution basis.

And we're doing a lot of listening right now so that we can develop because I think that you're going to have a lot of companies that are going to be proposing and going with a digital marketing tool. And unless you create something that meets the needs of the health care professional, it's going to fall on deaf ears.

So that's how we're utilizing the MRLs and TLLS right now is to understand how people want to be communicated to, if we are launching in a virtual setting..

And then to the second question Jason, the answer is simple. It's no. I mean the news which was seen a couple of days ago relates to an academic initiative by one of the knowledge institutes here in the cluster called VIB. They're working with single domain antibodies of camelids to go after this virus.

We have focused specifically on our ability to contribute through our C2 complement inhibitors. So there are no further antiviral or anti-infective initiatives going on in our company today..

Great. Thanks for taking the questions..

Thank you..

We will now be taking our next question from the line of Yatin Suneja from Guggenheim Partners. Please go ahead. Your line is now open..

Hi, guys. Appreciate the opportunity. Just on the MG pivotal study, a little bit of a positive surprise that all of the patients have completed the 26-week threshold probably two weeks earlier than we were anticipating.

So could you maybe talk about the next step as you start to lock the database? Do you need any more follow-up beyond the 26-week on all patients before you announce the data? Any other gating factor before you sort of lock the data and clean it up and sort of announce it and what the time line might be?.

Yes. Yatin, good to hear you and thanks for joining today. I'm not a clinical operations expert. So there are indeed a number of steps which have to do with cleaning data, verifying data, cross-checking the data before actually you go and lock it and you start to extract the data.

So you want to be absolutely sure about the quality of the database before you freeze it. And we all know that that takes actually some time. So in terms of next steps, these are the routine clinical operation steps which need to happen to have comfort in the quality of the database. But none of these individually would be a specific gating item.

It is true that for the top line data, we do need the full ADAPT 26 week's datasets, whilst then the open-label extensions study continues. And we will be able to extract safety information from that open-label extension study in order to further supplement the BLA filing with the required safety information..

Got it. That's helpful. And then just a follow-up on a previous question that somebody asked on the placebo side.

So in terms of other trials that have looked at similar end point, which is responder rate and a little bit different than that you have versus what Soliris did, are there other trial that we can look at beside your Phase II to get a better understanding of how the placebo might perform in these patients based on that end point?.

In terms of the longitudinal ADL and QMG curves, I would encourage you to really look at the REGAIN study. I mean this is the only decent study published out there where you can probably extract some learnings.

I think the placebo effect which they saw with their inclusion/exclusion criteria resembles the placebo effect which we saw with pretty much overlapping inclusion/exclusion criteria. So I think that it's probably the best study to guide you towards..

All right. Thank you very much..

Thank you..

We will now be taking one more question from the line of Yanan Zhu from Fargo Securities. Please go ahead. Your line is now open..

Hi, thanks for taking the question. So first question is on the ADAPT trial secondary end points. How would the results on the secondary end points affect approvability? And I'm particularly interested in the 26-week end points, which is obviously going to incorporate effect of flexible dosing.

So just wondering do you have to hit statistical significance on the 26-week end points for approval. Thanks..

Thank you for the question.

Keith would you mind taking this one?.

Yeah, happy to do so Tim. So first of all, I think probably the most important secondary end points that we have there is that this is the first trial to include these seronegative patients, so these MuSK LRP4 and agrin patients. The seronegative population is not a part of the primary endpoint.

The primary endpoint is only going to be on acetylcholine receptor positive. We did not want to put our Phase 3 study at risk in a patient population that we believe can benefit from efgartigimod, but we had not tested it in seronegatives yet.

So certainly if that secondary end point gives a similar result to the primary endpoint it can be label-enabling and we would be the first and only therapy approved for this population of MG patients, which is about 15% of the total MG population.

In regards to the additional secondary end points, we will disclose those and you will see that they will align to further build out and round out the successful primary end point by utilizing other scales like QMG and such.

To your question of a 26-week endpoint, the primary endpoint is measured in the first eight weeks, okay? And the other end points are measured throughout. But as far as the statistical significance it will occur. The statistical significance of the primary end point is observed only in the first eight weeks..

Got it. Thanks for the clarification. And also another question is on the pemphigus data that was just released. So just want to clarify a little bit about the 70% CR rate. I think that is based on 10 patients who were on optimal dosing defined as efgartigimod at least every other week plus a low-dose corticosteroid.

But I'm just wondering because the cohort three and cohort four had a total of 23 patients and it seems like the majority of them should be on at least every-other-week efgartigimod and as well as on low-dose corticosteroid.

So just wondering about how you arrived at the 10 patients and what are the reasons for the other patients not included in the calculation? Thanks..

Yeah. Thank you for that question. It was only in the last cohort that we actually specified the use of corticosteroids per protocol. Before that it was actually at the liberty of the investigators. And we were still triangulating our way through these data to come to the change in the protocol for Cohort 4.

What you need to know in Cohort 4 is that actually when patients reach end of consolidation, which is again an important clinical milestone, the patients were given the option to continue into CR or to actually already start to taper off corticosteroids. And that's where we learned the importance of steroid tapering for patients.

Actually that's why we show the third patient anecdotes in the presentation because this is really representative patients for those who actually elected not to go into CR, but to aggressively taper off these hated corticosteroids. For them it was more important to go to an acceptable level of steroids than it was to go to a PDI score of zero.

For those patients who actually opted to continue to go into CR these are the 10 patients. Indeed for these seven out of 10 on the optimal dosing regimen, we achieved the fast CR. So it's based on that information that now actually we can go and craft the Phase 3 trial design..

Thanks for the color..

Thank you for the question..

We will now be taking our next question from the line of Sandra Cauwenberghs from KBC Securities. Please go ahead, your line is now open..

Okay. Thanks for squeezing me in and thanks for the update today. I still have a question -- I know we touched already upon the competitive landscape for efgartigimod in MG with regard to competitors and late-stage trials on FcRn complement space subcu and IV. But I quickly wanted to touch base as well on the IVIg market.

What I've picked up is that this is a market that is quite severely hit today by the COVID pandemic which might last a little bit into 2021. Is this something that could be of benefit for the positioning of efgartigimod in 2021 so for the launch potential market share? And if I may still a small follow-up on PV the adaptive trial afterwards..

Sure Sandra you're very welcome.

Keith do you want to take question number one please?.

Sure. So, thanks for the question Sandra. And we have heard a rumor of potential IVIg shortage. And as you can imagine we monitor this situation because it does affect our patient population. In MG, it affects our patient population directly. In CIDP, it could have an enormous impact.

I don't think we can offer anything other than speculation at this time. The IVIg companies would be able to provide you a much more in-depth knowledge. So I'd rather not comment on what the situation is of their supply.

But we've always said that we believe efgartigimod can be positioned broadly across multiple indications that IVIg is utilized in today. And so it does present a potential increase in opportunity to disrupt the IVIg market..

Okay. Thanks. A follow-up question on PV on the adaptive trial specifically on the fourth cohort where I was intrigued by the combination of the tapering for steroids for the dosing there and the increase in efgartigimod dosing going up to 25 milligram per kilogram if I'm correct. And there was some efficacy seen on the skin tissue which was enhanced.

So, do you have any learnings that you can extract from that particular part of the study with regard to the mode of action for these patients?.

Yes, this is an interesting question Sandra. So, the ingoing hypothesis was that while everybody is measuring total IgGs in circulation nobody actually knows what happens in the different compartments outside of the circulation. So, the skin compartment specifically here is a question how much of the drug makes it and how fast into the skin.

We do know that efgartigimod has a very high-volume of pie distribution and is therefore traveling fast. But we wanted to see whether we maxed out the effect in the skin by maybe seeing differences in onset of action for example.

The truth is that it's difficult to compare between cohorts one two three and cohort four because in cohort four we happen to have the most severe patients of all and therefore it's very difficult to compare. But I think we expected some lessons learned.

We're going to communicate in the Phase III trial design when we will present to you the dose and the dosing schedule for efgartigimod. So stay tuned on this one..

Okay. Thank you..

We will now be taking our next question from the line of Damien Choplain from Kepler. Please go ahead, your line is now open..

Yes, good afternoon. Thank you for taking my question. I was just wondering why the recruitment in the cusatuzumab trials have been paused compared to efgartigimod trial that are still recruiting. I mean is it a question of indication or geography or maybe something else? If you could elaborate a bit on this would be nice. Thank you..

Thank you for that question. I mean there are two reasons for that. First of all, efgartigimod is a development plan which is completely under control of argenx only. And I think we did the benefit-risk analysis for our studies. And we concluded that for efgartigimod it was safe to actually continue to enroll patients.

In the cusatuzumab development we are 50/50 partners with Janssen so we are not making the decision alone. And secondly, we need to study of course specifically AML patients, which have a very much weakened defense system against infection. Actually infection is a very high risk of mortality, and therefore, the decision was taken to pause enrollment.

And it remains to be seen how exactly and when exactly we can resume enrollment to the trial.

Okay. Thank you..

We will now be taking our final question from Emily Field from Barclays. Please go ahead. Your line is now open..

Hi. Thanks for fitting me in. And I missed the beginning of the call, so I apologize if I'm asking any questions that could perhaps be redundant. I guess, I was just curious, I know you commented on potentially planning for hybrid launch, whether it's virtual or totally in person.

Sort of along with that, do you -- have you had any conversations with FDA, or do you expect that inspection of any manufacturing facilities could potentially be impacted by COVID if the pandemic were to persist? And secondarily, I don't know if you could talk at all about how you're thinking about pricing.

And if any of your thoughts have changed, if there is a potential that we could be entering a more protracted recessionary environment last year if that's something that enters your calculus at all. Thank you..

Thank you for these two questions, Emily. So Keith, I will hand over the question to you in a minute. With regards to question one, so far what we have seen and heard from colleagues in the space is that actually FDA continues inspection visits, but they simply do that in a virtual fashion.

So we can, of course, not look into the future, but today we know that FDA continues its activities, inspection activities in a virtual fashion. And that's what we're exactly preparing for.

And then Keith would your mind taking on question number two?.

Yes, happy to. So first of all, when it comes to the pricing of efgartigimod, we've said for quite some time that there's a lot of pricing research that we are taking into consideration that we are ongoing right now in particular when we see the data and the overall value to the patient on the annual treatment for MG.

There's a great deal of information that we're learning that will help us in pricing from our real-world evidence study, as well as some of the health economics outcomes research studies that we're doing. We have a large window to price in potentially for MG.

If you take a look at the high end of the spectrum where Soliris is which we will not be pricing up near Soliris, and you go down to what it costs for a patient to be on IVIg to treat MG, so there's a large window that we can play in.

Now to your point about how does COVID potentially impact this? What I had mentioned before is in the various work streams that we have in our launch readiness that we are doing all types of scenario play.

One of those work streams is obviously pricing and reimbursement, and you can take things into consideration like will we be looking at a larger population of unemployment? Does that mean there are going to be more patients on Medicaid? How does this affect overall out-of-pocket expenses? So it is considerations like that that we are taking -- learning -- taking in and learning right now and building our various scenarios of where we'll play.

And then finally, the last comment is as we go to set price for MG, we'll have a good idea on the progress and success of where we are with our other four indications with efgartigimod. So that will certainly weigh in..

That's very helpful. Thanks very much..

Thank you..