Good morning and welcome to the Y-mAbs Therapeutics Incorporated Third Quarter 2020 Earnings Conference Call. Today's conference is being recorded. Let me quickly remind you that the following discussion contains certain statements that are considered forward-looking statements as defined in the Private Securities Litigation Reform Act of 1995.

Because forward-looking statements involve risks and uncertainties, they're are not guarantees of future performance and actual results, they differ materially from those expressed or implied by these forward-looking statements due to a variety of factors including those risk factors discussed in the company's annual report on Form 10-K for the fiscal year ended December 31, 2019, as filed with the SEC on March 12, 2020, and in the company's subsequently filed SEC reports.

At this time, I'd like to turn the conference over to Thomas Gad, the company's Founder, Chairman and President. Please go ahead, sir..

Thank you, Jerry. Good morning everyone and thank you for joining us today. So the third quarter of 2020 has been strong for Y-mAbs. We believe we've made significant progress on executing our strategy. Naxitamab BLA is currently under review with the FDA as you know and the PDUFA date is coming up later this month.

Additionally, naxitamab has a rare pediatric disease designation, which means we are receiving a priority review voucher if naxitamab is approved. We are also expecting to resubmit the omburtamab BLA late 2020 or in the beginning of 2021.

In addition, the FDA has cleared our two INDs for the lutetium-labeled next-generation on omburtamab and we expect this exciting compound to enter into the clinic by the end of the year, targeting both pediatric medulloblastoma patients, but also B7-H3 positive brain metastasis in adult patients.

We ended the quarter 2020 with approximately $131 million in cash. So we believe we have a strong balance sheet to support the potential commercial launches of both naxitamab and omburtamab, while at the same time continue to advance the remainder of our development pipeline.

We also believe that our cash position should carry us through the end of 2022, without taking into consideration any product sales or potential partnership income, which Bo will elaborate on later on in this call.

As a company, we continue to work hard to stay true to our position in oncology field addressing clear unmet medical needs and focusing on advancing our therapies to reach the lives of pediatric patients living with rare disease.

Concurrently, I think it's very exciting to see our pipeline maturing into adult populations, such as lutetium-labeled omburtamab in adult B7-H3 positive cancers and our GD2, CD3 bispecific, which we anticipate will enter a Phase 2 small cell lung cancer study later this year.

We're also very pleased with the progress of our -- both of our technology platforms namely the Y-BICLONE bispecific platform, where we also have a CD33, CD35 bispecific plan to go into clinic for pediatric AML patients next year.

And our self-assembly disassembly radiopharmaceutical platform also referred to as SADA or liquid radiation as we like to call that. Today you'll hear remarks from Dr.

Claus Moller, our Chief Executive Officer who will provide a business overview; and from Bo Kruse, our Chief Financial Officer on our third quarter financial results and I'm pleased to hand over the call to Claus for that. Thank you..

Thank you very much, Thomas and welcome to Y-mAbs Therapeutics third quarter 2020 earnings call. We're very pleased that you have chosen to spend this morning with us. During the third quarter, we have continued to work hard to ensure that our pipeline including our lead candidates naxitamab and omburtamab advance toward the market.

As you know back in June the FDA has accepted our BLA for naxitamab for treatment of patients with relapsed/refractory high-risk neuroblastoma for priority review.

The FDA set a PDUFA date on November 30, 2020 and the agency also indicated that in the BLA filing communication letter that it is not currently planning to hold an advisory committee meeting to discuss the application.

If approved we expect that this indication will be approved under accelerated approval based on the overall response rate and duration of response. Continued approval for this indication may then be contingent upon verification and description of clinical benefit in a post marketing commitment.

We expect that the confirmatory post-marketing clinical trial required to verify and describe clinical benefit will be the Study 201, which is already ongoing. Study 201 will then have to enroll a total of more than 80 patients and measure overall response rates, ORR progression-free survival and overall survival.

The ORR is the primary endpoint of the study. The progression-free survival and overall survival are secondary endpoints in the long-term follow-up. Naxitamab has received priority review orphan drug breakthrough therapy and rare pediatric disease designations from the FDA.

And upon potential approval we believe naxitamab will be a much needed breakthrough for the patients with relapsed refractory neuroblastoma, who historically not have had any approved treatment available. At the International Society of Pediatric Oncology Virtual Congress in October this year otherwise known as SIOP, Dr.

Mora from SJD Barcelona Children's Hospital presented data from the company's pivotal 201 multicenter study. The central independent evaluation showed an overall rate of response of 68% and the rate of complete responses was 59% for the 22 patients presented.

In addition, bone marrow clearance was observed with complete response in seven of nine patients, who had positive bone marrow at trial start. The median duration of responses for long-term follow-up was at the time of the conference 27 weeks.

In addition to BLA, the BLA for naxitamab in relapsed/refractory neuroblastoma, we have trials ongoing in Barcelona and at Memorial Sloan Kettering in New York for first-line neuroblastoma as well as chemo combination trials for refractory neuroblastoma patients. Now turning to omburtamab our second lead compound.

In October, we received a refusal to file a letter from the FDA regarding the BLA for omburtamab for the treatment of pediatric patients, with CNS/leptomeningeal metastases from neuroblastoma. Our BLA was originally submitted in August 2020.

Upon its preliminary review the FDA determined that certain parts of the CMC module and the clinical module of the BLA required further detail. No additional non-clinical data have been requested or are required. And it should also be noted that no additional clinical trials of additional patients was requested in the refuse to file later.

Y-mAbs is confident that it can address all points raised by the FDA, including providing the requested additional CMC information and supplementary data from Study 101, which will include response data from patients with evaluable disease among the patients included in Protocol 101. In addition, an oral presentation at SIOP, Dr.

Kim Kramer from MSK presented interim results for 17 patients enrolled in the company's pivotal 101 multicenter study. The study showed a 12-month overall survival rate of 87% with a median follow-up of 26 weeks. This compares very favorably to an OS of approximately 30% in a historical control group.

The preliminary overall survival data results from the multicenter study 101 are encouraging and appears almost identical to the results of Study 03-133, which was conducted at the Memorial Sloan Kettering.

While recruitment is still ongoing, we are very pleased to see the preliminary omburtamab data in the multicenter setting that appears to support the conclusions from the MSK data.

We believe the preliminary survival curves are very similar to the original MSK data and this is good news for children with CNS leptomeningeal metastases from neuroblastoma.

As previously disclosed, we are also developing omburtamab for diffused intrinsic pontine glioma, known as DIPG in a Phase I study at MSK, and we are planning to open a multicenter Phase II study for DIPG patients this year. For desmoplastic small round cell tumors known as DSRCT, we recently opened a Phase II study at Memorial Sloan Kettering.

Let's now turn to the lutetium labeled omburtamab. In October, the FDA-cleared, our IND for 177 lutetium omburtamab DTPA, for treatment of medulloblastoma, which is one of the most common types of primary brain cancer in children.

Medulloblastomas are invasive rapidly growing tumors that unlike most brain tumors spread through the cerebrospinal fluid and subsequently metastasized to different locations along the surface of the brain and the spinal cord.

177 lutetium omburtamab DTPA embodies the company's naked omburtamab antibody radio labeled with Lutetium 177, using DTPA to chelate the lutetium radioisotope to the antibody.

We anticipate that an international multi-center Phase I/II clinical trial will be initiated for the screening of pediatric patients with medulloblastoma during this quarter, after the opening of the IND.

And based on our clinical experience, with Iodine 131 omburtamab for B7-H3 positive brain metastasis, we are obviously excited to see 177 lutetium construct make its way into the clinic to potentially establish a safety profile and to determine the maximum tolerated dose in these patients.

In this study, we hope to leverage our clinical experience, from treating 27 medulloblastoma patients with the Iodine 131 omburtamab, again using indwelling catheters for intracerebroventricular drug delivery also known as the Ommaya catheter.

In addition, the FDA has recently cleared our separate IND for a basket trial in B7-H3 positive CNS leptomeningeal metastasis cancers in adults, where we hope to leverage our prior experience from treating more than 25 adults, with Iodine 131 omburtamab.

We expect to initiate the study for the first adult patients to be treated with 177 lutetium omburtamab DTPA during the fourth quarter of 2020, and we are thrilled to widen our clinical reach to include adult indications. Now let's talk about Nivatrotamab, our GD2 CD3 bispecific antibody.

In September, the FDA granted orphan drug designation and rare pediatric disease designation to our leading bispecific antibody Nivatrotamab for the treatment of neuroblastoma.

Nivatrotamab is a humanized anti PD2 bispecific antibody in a Phase I/II clinical development in collaboration with MSK in patients with relapsed refracturing neuroblastoma as well as high-grade osteosarcoma and other PD2 positive solid tumors where patients have relapsed or are refractory to previously known standard therapy.

We plan to expand the ongoing study of Nivatrotamab into two separate Phase II arms one in neuroblastoma and one in osteosarcoma, as well as initiating a separate Phase II multi-center study in small cell lung cancer.

We expect to submit an IND for the lung cancer study during the fourth quarter of 2020 and we are excited to widen Nivatrotamab's clinical reach to include adult patients also. Turning to the commercial aspect, we are giving the small universe of pediatric cancer centers that treat the majority of the neuroblastoma patients.

We believe that we have built a lean and highly targeted commercial organization ahead of the launch of both naxitamab and omburtamab if approved. Assuming approval of naxitamab, our commercial team is in place and ready to launch naxitamab within a few weeks of its approval in the U.S.

and we believe we are also well positioned for the launch of omburtamab, if approved in the U.S. The European marketing application for omburtamab is potentially only a few months behind the U.S. and we plan to begin staffing our European commercial organization in the next few months. And then on to our exciting SADA technology.

As you will recall, in April we entered into an agreement with the Memorial Sloan Kettering Cancer Center and Massachusetts Institute of Technology for a worldwide exclusive license and research collaboration to develop antibody constructs based on the SADA radioimmunotherapy platform.

The SADA technology two-step payload delivery has been shown in an in-vitro setting to shrink or to completely eliminate tumors also in vivo in animals, while other tissues were spared. No clearing agent was needed and no significant toxicity to the bone marrow kidneys or liver tissues were observed.

We believe that the SADA technology may allow for rapid clearance of the compound, while maintaining high target uptake, and thereby causing less immunogenicity. In addition, the SADA technology appears to be modular whereby any data modified radioactive payload combined with any therapeutic antibody seems possible.

We are excited about the prospects of the SADA technology. And thus far we have announced four SADA targets in preclinical development. This includes our newest construct B7-H3 SADA, which we intend to use for treatment of prostate cancer.

We plan to submit the first IND for SADA construct in the second half of 2021, and we have high hopes to see liquid radiation transforms today's cancer treatments. Finally, a few more general comments, to support our growth plans, we increased our headcount about by 25 to a total of 114 employees during the quarter.

Due to the recruitment of sales force and supporting functions, the increase is significant compared to recent quarters. With the PDUFA date of naxitamab coming later this month, and the planned resubmission of the omburtamab BLA coming up, we believe that we are well positioned to transform Y-mAbs into a commercial state company.

Concurrently, we plan to widen and deepen our pipeline by advancing our antibody constructs through the clinic. Predominantly, the SADA constructs the bispecifics and the next-generation omburtamab radiolabeled antibodies. With this, now let me turn over to Bo and invite him to share his remarks on the second quarter financials.

Bo?.

Thank you, Claus. We reported net loss for the quarter ended September 30, 2020, of $32.8 million, or $0.82 per share basic and diluted comparing to a net loss of $23.9 million, or $0.70 per share basic and diluted for the quarter ended September 30, 2019.

We ended the third quarter with a cash position of $131 million, compared with the 2019 year-end cash position of $207 million.

As our work on the omburtamab BLA submission has progressed through the quarter and as we have continued to accelerate the commercial ramp-up for the potential launches of naxitamab and omburtamab, we've seen our cash burn increase.

We expect that the cash burn from operating expenses for the fourth quarter in 2020 to increase slightly, but remain roughly in line with the third quarter.

As we take a closer look at the operating expenses for the third quarter, we note that research and development expenses have increased by $1.3 million from $19.7 million for the quarter ended September 30, 2019 to $21 million for the quarter ended September 30, 2020.

This increase was primarily attributable to a $2.4 million increase in personnel costs $0.5 million increase in clinical trials and $0.4 million increase in professional and consulting fees. These increases were partially offset by a decrease of $2 million in outsourced manufacturing costs.

G&A expenses increased by $6.9 million from $4.7 million for the quarter ended September 30, 2019 to $11.6 million for the quarter ended September 30, 2020.

The increase in G&A expenses primarily reflected $2.2 million increase in personnel costs, $3.2 million increase in expenses for the building of our commercial infrastructure-related to the potential launch of our two lead drug candidates naxitamab and omburtamab and $1.6 million for business insurance and professional fees.

Cash used in operating activities as per September 2020 show that the cash burn increased by $24.6 million from a $48.9 million for the nine months period ended September 30, 2019 to $73.5 million for the period ended September 30, 2020. The increase was primarily caused by the increase in the net loss for the period.

The net loss itself increased by $41.5 million for the period ended September 30, 2020 and was partially offset by an increase in non-cash expenses including depreciation and stock-based compensation of $16.9 million. If naxitamab receives approval from the FDA, we will receive our first PRV.

Under the terms of the MSK license agreement, we are obliged to monetize the PRV and share the net proceeds thereof if any with MSK who will receive 40% of the net proceeds and the remaining 60% is going to us.

We've entered into an engagement level with a leading institution in the field of monetizing PRVs and assuming FDA approval of naxitamab expect to complete a transaction either late 2020 or in the beginning of 2021. It's worth noting that we also have received rare pediatric disease designations for omburtamab, Nivatrotamab and the GD2, GD3 vaccine.

So our point in potential approval of these compounds will have another three PRVs coming. In terms of financial guidance, since the secondary offering last year, we've said that the cash on hand would cover our operating expenses and capital expenditures through the fourth quarter of 2022.

This does take into account the potential net proceeds from monetization of naxitamab and omburtamab PRVs, but does not take into account any revenues we may receive from the commercialization of either naxitamab or omburtamab upon the potential approval all the proceeds we may receive from any potential future partnerships.

So we continue to believe Y-mAbs remains in a very healthy financial position. This concludes the financial update and I'll now turn the call over to Thomas..

Thank you, Bo. Okay. This concludes the remarks of -- our prepared remarks today. I think at this time, we will let the call go over for questions to Jerry and let's open up any Q&A session we have right now. Thank you..

Thank you. [Operator Instructions] The first question is from Robert Burns, H.C. Wainwright. Please go ahead sir..

Hi, guys. Thanks for taking my question and congrats on the quarter. Three from me right now if I may. So for the first one, one of the reasons cited by the FDA for the refusal to file letter was that they are requesting to evidence of anti-tumor activity I mean i.e. response rate data before proceeding with the filing.

Now unfortunately, we did not see any response rate data from the Phase 2 multicenter study of omburtamab presented at SIOP, despite it being a secondary end point.

Can you provide any color to the level of response we've seen in that trial? And is the FDA looking for a minimum specific response level here?.

So yes, let me start just replying to this. Well we have not presented the data yet and we're discussing to what level and how much the FDA wants to see. I can assure you that we are definitely having a group of the patients that are showing measurable disease and that we are seeing responses in these patients.

It looks like right now that maybe about 40% of the patient has measurable disease, but we're still a little early to say, how many we will be able to check measurable disease and look for eventual tumor responses are. But we are definitely seeing responses.

And I'm feeling comfortable that the level of responses will be able to present will be satisfactory to the FDA when we agree on all the details of the refiling..

Okay. Thanks.

So my second question is around the lutetium 177 labeled omburtamab, now considering that lutetium 177's maximum beta particle energy is not -- doesn't seem that much lower than Iodine 131, how reasonable do you believe it is that you may see a relatively similar efficacy benefit between the 177 labeled omburtamab as compared to the one -- Iodine 131 label omburtamab.

What does the market sizes look like for the B7-H3 positive medulloblastoma as well as these B7-H3 CNS mets tumors in adult patients?.

Well I mean the lutetium is correctly, it has an energy of about 80% of the electrons of the lutetium that are thrown off is about 80% of the energy of electrons thrown off in Iodine. So they're pretty similar. Half-life of the two isotopes also pretty similar five to six days for the lutetium and maybe seven days for the Iodine.

And so that also tells you that the penetration in tissues is almost like in the same ballpark with lutetium maybe be about 70%, 80% penetration in damaging versus Iodine. And therefore, we believe that it should be possible also to up the dose a little bit of the lutetium versus the Iodine 131.

Big benefit is that it's a lot easier to retro label with the lutetium on a DTPA elated antibody construct. Size of the market, I mean, it's very difficult, but for the adults -- for the pediatrics, the medulloblastoma is about 350 kids per year in the U.S.

So that's the ballpark size of the medulloblastoma indication, but the adult indication, we're looking at tens of thousands of patients per year dying from CNS leptomeningeal metastasis with B7-H3 positive cancers..

Okay. Thanks for that Clause. Last one for me and then I'll hop back in the queue.

So, given the proximity to an FDA approval for naxitamab in relapsed/refractory neuroblastoma, could you discuss a little more in detail now, how you're currently viewing the regulatory path and time line for potential label expansion into the frontline setting as well as for the HITS protocol?.

Yes. Well, I think, what we have said all along and what I'm still saying is, let the FDA approve naxitamab, then the idea is to ask for a Type B meeting and go back and discuss what do they need to see for a frontline study. And then -- so let's have that Type B meeting with the agency after we have gotten the approval.

But, as you know, we have two single center ongoing front line studies already. We have already presented the first set of data from Dr. Mora's frontline study about 11 months ago. And the MSK study is almost completely enrolled. It's supposed to enroll 59 patients. And so, very soon we should also have data for that.

So when we go to the FDA, we'll be able to bring data from two separate clinical studies in frontline and ask them about the potential design of a multicenter phase frontline study Phase II. And then, find out what more do they need to see. But as I said, let's get the approval for naxitamab in second line.

And the same goes for the chemo combination, that's also a discussion we would like to have with the FDA, for them to expand the label into a chemo combination, what more is needed.

Because we also -- as you know, we have a combination study with irinotecan-temozolomide and GM-CSF and naxitamab at both MSK and again a single center study in Spain investigator-sponsored by Dr. Mora there. And we are planning for additional studies in that setting also. So that's where we are now.

We need to talk to the FDA, get clear regulatory guidance from their side, rather than us second-guessing what they actually need. But we have data and we are definitely planning to meet and get that..

Awesome. Thank you, Clause. I’ll hop back in the queue and congrats again..

Thanks..

The next question is from David Lebowitz, Morgan Stanley. Please go ahead, sir..

Thank you for taking my questions. Given that naxitamab is going to be potentially launched very soon, could you just run us through, I guess, what we should look for in an initial launch? What type of, I guess, revenue growth could we see? I mean, the first market opportunity is clearly on the smaller side.

And what your sales organization looks like at this point?.

Sure. I mean, as you know, David, most companies are very cautious on predicting on sales when launching a new product. And so, what we -- having said that, we know there's about 300 kids a year that are primary or secondary refractory neuroblastoma patients and right now they don't have any approved therapy.

So those are the ones that we are going to start digging into and making our customers. But how many we will reach? Let's get the product approved, we will launch. And let's see how it develops in the first year. But we are definitely very excited. We have very strong expectations.

We also have a very strong collaboration with the Memorial Sloan Kettering still, as you can hear from everything that, I think, every second paragraph I was using had almost one reference to collaborations with MSK.

And they are very committed to using naxitamab and have been using it, both in frontline and second-line and third-line for neuroblastoma patients in various combinations or as monotherapy for the last five years. So they would obviously continue doing that, even if naxitamab becomes a commercial product, rather than a clinical development program.

So in terms of the sales team, we have our 10 people in the sales organization those that actually are responsible for visiting doctors. They are all in place. We have our medical science liaisons and research nurse team, also set up and ready to go.

And, of course, the whole additional support organization with the market access and marketing and co-pay, et cetera. All this has also been set up and are ready to go. So, everybody is extremely excited these days and we're continuously monitoring for any final and new development.

And I'm very confident that we are very close to a potential marketing authorization for naxitamab..

Thank you for that.

And looking over to the omburtamab franchise, could you just, I guess, discuss the challenges of having such a therapy being prescribed by, I guess, radio pharmacies at the hospitals and how that dynamic could differ between the iodine and the lutetium version?.

Well, I think, it's more kind of a productivity issue. Right now, the -- what we are planning for and as a part of our BLA are suggesting is that, we are responsible for the radio labeling of the omburtamab with iodine. So that means that our central radio labeling is happening.

We are releasing the ready-to-use product with a potential use within 72 hours. And so, the only thing that radiopharmacy at the hospital need to do, and that is a requirement for the hospital, they need to have a radiopharmacy, but any large hospitals in the U.S. has that and definitely all the hospitals treating pediatric oncology.

So the only thing that the radiation pharmacy needs to do is, to receive the radiolabeled antibody in the little lead box and check and control everything and pull out the radioisotope, the radiolabeled antibody from the vial in a syringe that contains the dose, the prescribed dose with a 50 millicurie radioactive iodine and then put that in a different lead box and send it up to the department and then they are ready to inject.

So it's very simple. There's no tricky steps. They don't need to do anything but check what they're receiving is what they order. And make sure that the total amount they track up and the syringe is equivalent to 50 millicurie of radioisotope antibody. And that's it. If we look at the lutetium, it's going to be exactly the same.

We will deliver ready-to-use lutetium labeled antibody and the dose and the -- typically the vial will contain maybe 80, 90 millicurie of radio actively labeled antibody and it will have a prescription saying that, X microliters of this solution contains Y millicurie.

And then the radiopharmacy is responsible if the patient is prescribed 50 millicurie, they will take that dose out of the vial and the rest is discussed by the radiopharmacy. The lutetium is exactly the same. They will just have X amount of lutetium labeled antibody in the vial.

But for us, as a company, it takes about one-and-a-half hour to radio label the antibody and quality check it and put it in a vial, pack it and ship it off. Whereas when we radio label with lutetium, it takes 15 seconds.

So it's a much easier radio-labeling process and we don't need to double check that it still has the necessary binding affinity because it's -- lutetium never affects the binding affinity of the antibody at least until what we know today, but it's giving good reasons because, the challenge with the omburtamab Iodine is that the Iodine is known for sometimes disrupting the binding side of the antibody because, one of the tires seem to -- is sitting pretty close to the binding side.

Now it becomes technically. So to summarize shortly, it's a lot easier for us to radio label with lutetium. It's a more stable product. And therefore, we can ship it out to tens of thousands of patients every year. Whereas for Iodine, it's definitely doable to send out a couple of thousand vials per year and you can probably scale it up a bit more.

But it's just much easier with the lutetium construct..

Thank you for that. Appreciate it..

The next question is from Etzer Darout, Guggenheim. Please go ahead, sir..

Great. Thanks for taking the question. Just a couple for me. But first, maybe if you could elaborate a little bit on the Type A meeting with the FDA on omburtamab and what's your positive takeaways from that interaction with respect to sort of the refiling of the BLA. And I have a second question..

Sure. I mean, it's pretty clear that on the CMC, we have resolved all the issues that they have requested and we are ready to put that together in a resubmission package. There are still some issues, we need additional clarification on in terms level of response rates and number of patients they want to see response rates from.

And they and us, are still discussing it. We are putting a briefing package together for them to be resubmitted next week. So, we are on the track, as we have said to get everything put together and I'm very confident that we will be able to do that. That was referring to the Type A meeting.

Your other question was?.

Yes. So the other question was on the bispecific programs. I guess, first, with the GD2 bispecific asking the obligatory question, as to when we may be able to see sort of the initial data. And then on the CD33 T cell engager, any potential differentiation that you are seeing preclinically from other programs? And maybe some color there..

I think it's too early for us to give any details on that. I think we have said that we are trying to see, if we can present data on a company science day update that we hope to hold in December this year.

So, don't hold your breaths for it, but look forward to the company update in December, where we hopefully can provide the first data sets from the bispecific antibody study..

Great. Thank you..

We have a question from Alec Stranahan, Bank of America. Please go ahead..

Hi guys, thanks for the update and thanks for taking our question. Just two from me.

First, with the studies for omburtamab DTPA getting underway, can you just help us frame, whether there are any unique differences in these expanded patient populations from omburtamab 131 in the pediatric setting in terms of limitations with delivery method or preference for individual tumor types in the adult study? And I guess along those lines, do you see the intracerebroventricular administration made capping expansion into some of these larger patient populations? And secondly for naxitamab in frontline neuroblastoma, how compelling for physicians and patients do you see removing the need for standard ASCT in this setting? And do you think this alone could be enough for clinical adoption? Thanks..

Alex, let's start with the first question about the omburtamab DTPA. Then we can get back to your second one. So, you were asking about the DTPA.

And as I said, the medulloblastoma as I also reported earlier is an indication where we already have seen some indications of efficacy in the 03-133 study, where we treated already 27 patients with medulloblastoma. And we're kind of looking at this as a very important setting.

And rather than using the neuroblastoma patients, where we already are achieving very great results, we wanted to see if there was a possibility to further increase the dosing and the efficacy of omburtamab in a population, where we are seeing clear signals of efficacy.

And therefore, it was a nice and perfect fast track pass for the omburtamab DTPA lutetium from a development perspective to go on with the medulloblastoma. We have clinical evidence from the iodinated form and we have a group of patients with an unmet medical need and we are staying true to our commitment to develop pediatric oncology compounds.

So that made a lot of sense and it's also attracting quite a bit of interest from pediatric brain tumor consortiums in the U.S. to participate in that development. And yes expanding with this construct, the DTPA conjugated omburtamab into the adult setting is clearly going to increase the number of patients.

Will the Ommaya catheter, the intraventricular catheter be a limiting factor? I don't think so. I think a neuro surge run in both Europe and the U.S. is perfectly skilled in placing these catheters. And it's kind of like in my opinion just a CNS portacath. And any surgeon can put in a portacath and any neurosurgeon can put in an Ommaya catheter.

So, I don't foresee that being a limiting issue. And there almost never any issues because the vessel vial is placed under the skin. So, you don't have infection risks from the outside. So it seems, as it's pretty safe and a clear possible way forward for these constructs. That was the omburtamab question.

Then you had a question about naxitamab also?.

Right. Yes, the first line ASCT and whether this is a decision for clinical adoption in your view..

The first-line, I'm not sure I understand the question..

Right.

So first-line neuroblastoma, I guess how compelling would be removing the need for standard ASCT setting?.

I think, my take on this is that, if we can show that we have similar long term call it two year entry survival with naxitamab and we can show that we have a significant reduction in the hospitalization and the use of morphine when treating frontline neuroblastoma patients with naxitamab versus dinutuximab, it's pretty well-established what the days of hospitalization and the use of morphine is for patients in frontline treated with dinutuximab.

And if we can show that the number of hospitalization days goes from 35 to 40 days per five cycle treatment goes down from that to less than three days which we know, we have less than one day on average with naxitamab, and at the same time, the total use of morphine goes down from X to 0.25x, I mean we have shown what I would consider a clear clinical benefit if there's -- even if there's no significant difference in side effect profile.

And I think you will see that the side effect profile, although we of course also see side effects hypertension and pain with naxitamab compared to the amount of side effects you see when giving dinutuximab in frontline in combination with IL 2, which is the indication that they have is significantly lower.

So I think that -- what would it take to be compelling? As I said significant reduction in use of morphine and hospitalization and serious adverse events and at the same time same level of two-year event-free survival.

And two-year event-free survival is pretty well-established for without PD2 antibody 40% to 45% two-year event-free survival with dinutuximab, 60% to 65%. And the only data we have seen so far is Dr. Mora's two-year event free survival of about 70%. So -- and that was on his first 37 patients. And that was very compelling..

Thanks..

Thank you..

We have a question from Anupam Rama, JPMorgan. Please go ahead sir..

Hi, guys. Thanks so much for taking the question, and congrats on the progress. Just a quick clarification question on the GD2-GD3 vaccine.

Sorry, if I missed this in the opening comments but the Phase II trial in neuroblastoma is supposed to start in the first quarter of next year, right? But what are the gating factors to starting this study? Thanks so much..

Yeah. We are still looking at the combination with the beta ligand that they have been using and discussing with MSK both the sourcing of the beta ligand and the eventual need for that. And but besides that there are no major gating factors.

And we're also discussing with patient organization about a -- the first study we're looking at is to start a study in second CR. There's clearly an interest of participating in a frontline study from patient organizations with the vaccine where you randomize between vaccine and placebo.

But besides all the other things that we also need to do, I don't see any significant gating factors..

Great. Thanks so much for taking our question..

Next question is from Peter Lawson, Barclays. Please go ahead sir..

I like the pronunciation of my name, I become more European. So it's Peter Lawson, Barclays. And just on -- I may have missed this. I apologize as well.

So the initial data for the GD2-CD3 bispecific, is that going to be your potential R&D Day? And like what could we see would that be patient responses to that point?.

I don't have any data that I've seen yet, but it's our plan to treat -- how much we can track out of the database and have it available for our update scientific update in December..

Okay.

And then just on the random criteria data for omburtamab that the FDA requested would we see that as well at some point?.

I definitely plan to see if we can present it at scientific update data also if we cannot disclose it before..

And that would be a scientific conference not at your R&D Day?.

No. I think we will try to -- because I know that there's such a big interest for what we have available. So we would probably try to see if we can communicate at least preliminary evaluations of that. But as I said it's -- and I don't think it would be fair to wait.

So if we haven't said anything before, I would definitely try to see if we can present what we have available at the scientific update there..

Got you. Thanks.

And then how should we think about the cash runway just with series of launches and the potential monetization of vouchers?.

I'll let Bo answer that question..

Yeah. So frankly Peter, I didn't hear your question. I was just making some other notes on the financing runway..

On the cash runway, just with the potential launches and then the monetization of the vouchers, how should we think about the runway?.

So basically the launches themselves if they happen would, of course, require some funding. However in spite of that, we are good through the end of 2022 including only our current cash position and the net proceeds from monetization of the two PRVs for -- on naxitamab and omburtamab.

So when we say that we're good through the end of 2022, it's excluding the product revenues and any income from potential partnerships..

Thanks so much. Thanks for taking the questions..

We have a follow-up question from Robert Burns, H.C. Wainwright. Please go ahead sir..

Hi, guys. One more question for me.

So given the advantages of also allowing for scintigraphy and subsequent dosimetry with the lutetium labeled omburtamab in addition to the manufacturing advantage that you guys would have with that asset do you envision potentially developing the lutetium labeled omburtamab in a manner with which you could potentially replace 131 omburtamab in the indications that 131 is going after?.

Well, I mean, it's a fair question. I think in the end, it's uphill to start doing a new study in the leptomeningeal metastases from neuroblastoma or even the DIPG where we already have more than 40 patients on the study and we are starting a Phase II multicenter study in DIPG before year-end this year. So I do not foresee that.

I foresee that we will have primarily the omburtamab DTPA lutetium for the adults and we will keep for the first indications because you know as well as I do, we're just starting Phase I/II studies now with omburtamab DTPA. So we are looking at something that potentially could come to the market.

I mean, if we are really world record setters in developing new drugs six, seven years from now, we could have the product in the market. And omburtamab hopefully comes to the market next year.

So I do not foresee planning to substitute omburtamab in the first indications that we're getting approval for with the iodinated version with anything for the next six to seven years. And if you know what you're doing six to seven years from now let me know, because I don't know what I'm doing six to seven years from now..

That's completely fair Claus. Thanks for taking the question and congrats again..

Okay. Thanks again..

There are no further questions at this time. I'd like to turn the conference back over to management for closing remarks..

Well, thank you everyone for dialing in and participating. And look forward to continuing Y-mAbs and have a great weekend. Thank you. That concludes the call..

This concludes today's teleconference. You may disconnect your lines at this time, and thank you for your participation..