Good afternoon everyone. Thank you for standing by and welcome to the Atara Biotherapeutics Fourth Quarter and Full Year 2020 Financial Results Conference Call. At this time, all participants are in a listen-only mode. Later, we will conduct a question-and-answer session and instructions will follow at that time.

[Operator Instructions] As a reminder, this conference call is being recorded. I would now like to hand the conference over to your speaker today, Eric Hyllengren, Vice President of Investor Relations and Finance at Atara Biotherapeutics. Please go ahead, sir..

Thank you, operator. Good afternoon everyone and welcome to Atara’s fourth quarter and full year 2020 results conference call. On today's call, members from the Atara executive team will provide an update on our 2020 financial results and operational progress and also review our upcoming key milestones and objectives.

Earlier today, we issued a press release announcing our fourth quarter and full year 2020 financial results and operational progress. This press release and an updated investor presentation are available in the Investor & Media section at atarabio.com. Joining me on today's call are Dr. Pascal Touchon, President and Chief Executive Officer; Dr.

Jakob Dupont, Executive Vice President and Global Head of Research and Development; Utpal Koppikar, Chief Financial Officer; Joe Newell, Chief Operations Officer; Dr. AJ Joshi, Chief Medical Officer; and Kristin Yarema, Chief Commercial Officer. We will begin with prepared comments from Pascal and Jakob, then open the call up for your questions.

We would like to remind listeners that during the call, the company's management will be making forward-looking statements. Actual results could differ materially from those stated or implied by our forward-looking statements due to risks and uncertainties associated with the company's business.

These forward-looking statements are qualified in their entirety by the cautionary statements contained in today's press release and the company's SEC filings. These statements are made as of today's date, and the company undertakes no obligation to update these statements. Now, I’d like to turn the call over to Pascal.

Pascal?.

Thank you, Eric and thank you all for joining us this afternoon. In the fourth quarter of 2020, we advanced very significantly our three strategic priorities; Tab-cel, ATA188 in multiple sclerosis, and our next-generation allergenic CAR T programs. For Tab-cel, Atara is on track to complete a rolling BLA submission for EBV positive PTLD in Q3 2021.

As a reminder, we have already completed the preclinical module 4 in alignment with FDA requirements.

We are ready for initiating rolling BLA with this module once the FDA decide upon compatibility or not of the drug product manufactured by your academic partner for the historical non-pivotal studies and the one manufactured by Atara for the pivotal study.

Recall that FDA has already agreed that the non-pivotal studies will be supportive clinical data in the BLA submission in any case, and that this positive decision will just determine whether we provide the data as pooled or parallel analysis with a Phase 3 ALLELE data in a clinical module five.

Meanwhile, we are in frequent and productive discussion with the FDA on the content of CMC module 3. In fact, we just had an informal teleconference with the FDA CMC reviewer late last week, and we are making progress with the agency on the final content of this module.

Our plans remained unchanged, but we expect to initiate a rolling BLA and then complete the BLA submission with a clinical module in Q3 of each year once we add the final clinical data required by the FDA. And finally, in Q4, we expect to present data from the Phase 3 ALLELE study at an appropriate Congress.

With regard to a Tab-cel Phase 2 multi-cohort study in patients with other individuals and count cells, the opening of the clinical study sites is accelerating and the sites are actively evaluating potential study participants. As a reminder, there are six study populations, which may support meaningful label expansion.

The largest two are EBV+ AID-LPD and add EBV+ PID-LPD for which there is a high unmet need and a similar mechanism of disease to PTLD.

Most recently, new Tab-cel data in patients with life-threatening complication of EBV viremia were presented at ASH 2020, showing 50% to 80% objective response rate and overall survival at one year of 100%, for a median follow-up for 14.6 months.

Over the last 12 months, we have made significant progress on the manufacturing front in building Tab-cel inventory. Successfully HLA matching 89% of patients eligible for screening in a Phase 3 ALLELE study. We are on track to reach our goal of over 95% of PTLD patients cover at the time of commercial launch.

We have started to invest further in our U.S. commercial readiness activities in anticipation of Tab-cel approval and planned launch in the first half of 2022. We intend to undertake a very focused commercial approach consistent with rare disease models.

By the way, yesterday was Rare Disease Day in the U.S., which we were proud to support as patients with rare cancers like PTLD need to know that they are not alone in their fight. Atara's activities are already underway for disease area education, identifying key providers accounts, and performing specific analyses to support Tab-cel value story.

We believe that the unique attributes of PTLD as a serious and deadly disease with no approved therapies. Together with Tab-cel potential unique benefits as a transformative therapy support the targeted and highly efficient commercialization model.

Regarding Tab-cel in the EU, which has time designation of Pediatric Investigation Plan or PIP was approved in December 2020. In fourth quarter of this year, we plan to submit an EU marketing authorization application for Tab-cel in EBV+ PTLD. Recently, we announced we are seeking a partner for the commercialization of Tab-cel outside the U.S.

and discussions with interested parties have started. Moving on to ATA188, or potentially transformational multiple sclerosis program for patients with poverty form of MS. And rollout is progressing well in the Phase 2 randomized double-blind placebo-controlled study or RCT, following first patient enrolment in June of 2020.

Atara will conduct an interim analysis for this study in first half 2022, including efficacy and safety in patient with progressive firms of MS. Following the IA, we expect to complete enrollment of this Phase 2 study in first half 2020.

Ahead of the IA next year, we plan to present in second half of 2021 long-term two-year clinical data from the Phase 1a open label extension or a lead study, as well as translational data from the Phase 1a.

Recently, we've seen increasing momentum independent publications and review articles, reinforcing the association between EBV and MS, as well as possible rationale for EBV latent infection to be a triggering factor for disease progression.

In parallel, we are seeing significant interest from patients, patient advocates, and physicians in our RCT and separately significant interest from a number of large companies regarding the potential of collaboration involving ATA188. Turning now to a differentiated next generation CAR T portfolio.

Atara CAR T programs are based on EBV T cell platform and our ability to leverage new technologies such as novel co-stimulatory domains like 1XX, and novel armoring technology, like PD1 DNR to improve efficacy, persistence, and durability of response, hence addressing limitations of [Indiscernible] and other allogeneic CAR T.

In December of last year, we announced a strategic collaboration with Bayer for the development in CAR T program.

While only a few months have passed since the collaboration began, the rollout has been very smooth due to the commitment of both parties to bring lifesaving cell therapy to patient and also both parties prior expertise in meditating as an oncology target.

Our partnership with Bayer allows us to accelerate and expand the development of ATA3271, our allogeneic Mesothelin targeted CAR T to parallel studies in multiple germaphobes potentially speeding its delivery to patients and creating shareholder value. Atara will perform IND enabling studies and process development for ATA3271.

Bayer will submit the IND expected in Q2 or Q3 of 2022 and lead its subsequent clinical development and commercialization. For ATA3219, our allergenic CAR T for patients with B cell malignancies, Atara recently presented exciting preclinical data that Jakob will detail shortly.

We plan to submit an IND for ATA3219 in Q4 2021 or Q1 2022, in line with our strategic goal to develop the asset as best-in-class in B cell malignancies. Now moving on to our financials. With regard to a cash position and runway, we ended the fourth quarter of 2020 with $500.7 million in cash, cash equivalents, and short-term investments.

This cash balance includes the net proceeds from the upfront cash payment from the Bayer collaboration, proceeds from the December 2020 financing, and proceeds from stock sold through our ATM facility. With this cash balance and projected revenue from U.S.

Tab-cel sales, we believe we are sufficiently funded into 2023, inclusive of expenses for the BLA filing and U.S. commercial launch of Tab-cel. Reflecting now upon Atara in 2020, a highly unusual and challenging year for all due to the COVID-19 pandemic.

I would like to express gratitude to extraordinary Atara staff whose tireless efforts enable the company to deliver on our milestones.

In the past year together, we conducted the Tab-cel IA, made significant progress on the Tab-cel regulatory front, initiated the ATA188 RCT, initiated a CAR T clinical study, and signed CAR T strategic collaboration with Bayer.

Not only did we meet these extraordinary milestones doing what we say we will that the Atara team also stepped up to support one another during the global pandemic, an incredible achievement.

Atara's progress in leveraging our unique allogeneic EBV T cell platform to deliver transformative therapy to patients during a challenging year like 2020 is only possible because of the perseverance of Atara staff in collaboration with patients, caregivers, academic, and industry partners, as well as investors.

I will now turn the call over to Jakob.

Jakob?.

Thank you, Pascal. Now, as Pascal mentioned earlier, we've made tremendous progress across all three of our strategic priorities in 2020 and are poised for continued success this year. For Tab-cel, we continue our plans to initiate the rolling BLA and are on track to complete the rolling BLA submission for EBV+ PTLD in Q3 of this year.

We remain on track with and continue to have frequent and productive conversations with the agency on the most appropriate and expeditious pathway to approval for this life-saving therapy.

In addition, through our advanced and leading process science and manufacturing efforts, we have created reliable and reproducible allogeneic cell therapy products like Tab-cel and ATA188. Evidence of our advanced manufacturing was recently featured at last month's 2021 Transplantation and Cellular Therapy or TCT Meeting.

At that meeting, we presented for the first time transcriptional data for Tab-cel demonstrating consistency of the products activation profile, irrespective of donor and consistent enrichment of receptor targeting EBV-driven diseases. The study evaluated the in-vitro characteristics of Tab-cel that help elucidate its proposed mechanism of action.

These results demonstrated that upon stimulation Tab-cel exhibits a consistent activation signature at a level of gene expression to cell receptor engagement and secretion of factors associated with effective T cell responses.

We've made significant progress on manufacturing a consistent off-the-shelf drug product, which is critical in order to get Tab-cel the PTLD patients who had very limited options and can't wait. Continuing with our program ATA188 for Multiple Sclerosis.

Recently, we provided an update to our discussions with the FDA regarding the ATA188 clinical data, the design of the randomized control trial and potential registrational path for this potentially groundbreaking therapy and multiple sclerosis.

Regarding the registrational path for ATA188, the FDA articulated a preference for an EDS as improvement endpoint and agreed the patient population criteria that Atara used to define patients with non-active secondary progressive MS and non-active primary progressive MS are appropriate for registrational studies.

Furthermore, the agency agreed that our Phase 2 RCT study duration should be at least 12 months after the initiation of treatment.

Based on this feedback from the agency, we've amended the study protocol, changing the primary endpoint of the study to EDS as disability improvement, assess the 12 months, and increase the number of patients to 80 to accommodate for this change. Biological and functional endpoints will still be maintained.

In our discussions, the FDA also agreed to an interim analysis and the ongoing Phase 2 RCT and that statistical power should be allocated to this IA for the sake of rigor.

The timing of the IA and the Phase 2 RCT will be the first -- in the first half of 2022 and this will include efficacy and safety, and shortly thereafter, enrollment will be completed also in the first half of 2022. We will have a number of options for the AI data.

Firstly, we can discuss with the FDA the potential to amendment study for registrational intent based on the FDA feedback. Secondly, with the data we can discuss with potential partners, opportunities for partnering; and thirdly, we can make sample size adjustments to the trial since the IA will occur before enrollment is completed.

Furthermore, the body of evidence supporting the potential role of EBV in Multiple Sclerosis continues to grow as highlighted in the recently published New England Journal of Medicine review paper, by [Indiscernible] and Hauser from UCSF. This review paper adds new information regarding EBV and that it may be implicated in Multiple Sclerosis.

Now, we know that EBV is implicated in the pathogenesis of MS. Specifically, from other evidence; we know that 100% of MS patients are EBV+. EBV infection appears to be necessary for the development of MS in genetically susceptible individuals. There's also a strong correlation between the presence of EBV antibodies in the blood and disease onset.

EBV-infected B cells and plasma cells can also be detected in the brain of patients with Multiple Sclerosis and there have also been reports of elevated antibodies against EBV antigens such EBNA1 being associated with more MRI disease findings MS like cortical atrophy.

Now, with the New England Journal of Medicine publication, we find that there is another argument added to the EBV-MS hypothesis. Specifically the publication reviews how EBV may be involved in molecular mimicry, in which protein sequences in EBV can induce a CD4 T cell immune response that can also target a protein in the brain.

As such EBV may trigger the pathological cascade of MS.

As noted, the body evidence for EBV as a causative agent for the development of Multiple Sclerosis is growing and we are enthusiastic about our ATA188 program that specifically targets EBV infected cells in Multiple Sclerosis with the hope of providing significant clinical benefit to these patients. Turning now to our CAR T programs.

As Pascal mentioned, we recently started a strategic collaboration with Bayer for Mesothelin CAR T therapy specifically ATA2271 and ATA3271 for the treatment of solid tumors.

Starting with ATA2271, or Autologous Mesothelin targeted CAR T, we've already started enrolling patients as performed by our collaborators at Memorial Sloan Kettering to an open label Phase 1 clinical study. ATA2271 incorporates both a novel 1XX co-stimulatory domain and a PD1 dominant negative receptor for intrinsic checkpoint inhibition.

Initial Phase 1 one safety and efficacy data for ATA2271 are targeted to be presented in Q4 of this year. We're excited about the potential for this innovative construct which is being used for the first time in this setting.

We believe this approach could be a way to address the prior challenges other CAR T have had in successfully treating solid tumors. Now turning to 3271, the first preclinical results of ATA3271 are allogeneic EBV CAR T cell therapy targeting Mesothelin designed for the treatment of solid tumors were presented at SITC recently.

Findings from in-vitro ATA3271 study shows potent anti-tumor activity against Mesothelin expressing cell lines and potencies maintained in the presence of high tumor PDL1 expression.

These data support the design of ATA3271 to maintain function in the presence of suppressive PDL1 expression commonly associated with solid tumor microenvironment, including mesothelioma non-small cell lung cancer and other solid tumors.

In addition, results further support the combined functional design of ATA3271, 1XX co-stimulatory domain technology and maintaining a memory phenotype, while limited cell exhaustion in the content -- context of repeated tumor cell challenges, which could be particularly important for the success of CAR T therapy in solid tumors.

Now, in-vivo ATA3271 exhibits potent anti-tumor activity and significant survival benefit in mice implanted with mesothelioma cells and highly -- that highly expressed both Mesothelin as well as PDL1. This in-vivo potency was demonstrated without evidence of toxicity such as allocytotoxicity.

Both in-vitro and in-vivo results for ATA3271 suggested allogeneic Mesothelin CAR T engineered EBV T cells are a promising approach for the treatment of Mesothelin positive cancers.

Now finally, with regard to 3219, our next generation off-the-shelf allogeneic CD19 CAR T utilizing again 1XX technology without the need for TCR editing for the treatment of B cell malignancies, we are on track to submit an IND in Q4 of this year or Q1 of next year.

We presented promising preclinical data showing potent anti-tumor activity both in-vitro and in-vivo, with long-term functional persistence and no evidence of allocytotoxicity in-vivo at the December 2020 American Society of Hematology Annual Meeting.

Preclinical results presented at ASH detailed findings from in-vivo and in-vitro evaluations of ATA3219. Specifically, the studies demonstrate potent anti-tumor activity of 3219 against CD19 expressing target cells and in-vivo against the disseminated tumor model of ALL.

We believe these results are associated with long-term persistence and survival benefit. In addition, both in-vivo and in-vitro assessments of 3219 allocytotoxicity support a potentially favorable safety profile that would be required for an allogeneic off-the-shelf CAR T cell therapy.

Together these findings support advancing ATA 3219 to clinical evaluation. I would like to conclude by reiterating Pascal's comments of thank you to our Atara staff, collaborators, patients, and caregivers. We could not have accomplished this much in 2020 without your dedication to bring these lifesaving therapies to patients.

I will now turn the call back to the operator to begin Q&A portion of the call.

Operator? Operator?.

Hello operator, ready to begin the Q&A portion please.

Well, operator, can you hear us, we're ready to begin the Q&A portion please?.

Yes, thank you. [Operator Instructions] We have our first question coming from the line of John Newman with Canaccord. Your line is open..

Hi, guys. Thanks for taking my question. Congrats on the progress in 2020, especially such a difficult year for everyone. I just have two quick questions.

The first one regarding the Tab-cel rolling BLA submission, I'm just curious if the agency needs to come to a definitive conclusion as to whether they consider the prior Tab-cel material comparable to the current material? Or if perhaps you might be able to just submit both analyses at some point and let them choose? The second question on the Mesothelin CAR T program, just curious if we might happen to get an update from the study that Sloan Kettering had running, started a few years ago? I'm just not sure if they might give us an update earlier this year, or if we will wait for your product later this year? Thanks..

Thank you, John, for your questions.

Jakob, do you want to take the first one?.

Sure. Thank you, Pascal, and, John, thank you for your question. So, I'll begin by saying we've had productive and frequent discussions with the FDA and that's obviously because of our breakthrough therapy designation status.

The focus of the current discussions is to secure all the guidance that we need to complete our module three or the CMC module of the BLA.

In parallel, with gaining the necessary guidance on completing module three, we also are expecting resolution to the procedural decision from the FDA whether we can submit the clinical data from the historical non-pivotal studies as pooled or parallel as you're alluding to, and that's obviously data -- with data from the 302 or LEO study.

So, overall, we're very pleased with the progress that we've made with the FDA and we are on track and this is really important to complete the rolling BLA submission for Tab-cel in the third quarter of this year..

Thank you.

On the second question about the third generation academic study that was done with different Mesothelin CAR T, Jakob?.

Absolutely. So, thanks for the question, John, on the academic Mesothelin program. So, importantly, for Atara, as you know, now in our partnership with Bayer, we have these two programs, 2271, which is the autologous program and then 3271 which is the allogeneic program.

So those are the ones that Atara over see in collaboration with our partners now at buyer. Now, as you alluded to, there is an academic program that preceded the Atara partnership. And this had the Mesothelin binder in it and it was a more conventional or first generation co-stimulatory domain there.

Now, we are separate from that program it's not part of the Atara partnership. So in that sense, we don't have insights into when -- the colleagues at Memorial Sloan Kettering going to be producing that data? But certainly, we look forward to any updates from them..

Yes. And we know they're continuing to follow the patient. So one might expect some data at some stage but this is not being supported or funded by Atara.

Does it answer your question, John?.

Yes. Great. Thank you very much..

We have our next question coming in from the line of Salim Syed with Mizuho. Your line is open..

Great. Thanks so much for the questions, guys. There's a couple from me on ATA188.

So, Pascal or Jakob on the interim analysis that you'll be conducting in the first half of 2022, I'm trying to understand, what you guys would perceive to be a best case scenario here, worst case scenario and a middle case scenario? I know, we've sort of touched on this before where you can increase the end, a little bit or you can go large here.

And is there a futility analysis? So just maybe some color on? How should we be perceiving the different scenarios coming out of the RCT -- fee increase and a little bit or a lot, or nothing at all? And then just a second question on the OLE, I noticed in the slides, that you're no longer presenting first half 2021 OLE data.

And I'm just curious why that's the case? Thanks so much..

Thank you, Salim for your question, AJ do you want to answer the first question, please?.

Sure. Thanks for the question, Salim. From the -- from the perspective of the interim analysis, this is going to be kind of your classic interim analysis where we spend some alpha to take a look at everything. So this is going to be you know, efficacy, safety, all those general parameters you'd look for.

So in any one of these kinds of analyses, you look at everything, right? You know, I think the best way to look at this is, from what we do, coming out of that interim analysis you'll have a pretty good idea of what -- where we're going, right. So -- and we'll try to be as clear as possible once we make any adjustments to design.

So once we see the interim analysis, to your point earlier, we've got a robust Phase 2 study design, a small increase in sample size maybe something that we do just to make it a bit more robust.

A large increase in sample size match would be an opportunity where we're having discussions with FDA, where they're thinking that this can be more supportive of even a larger registrational pathway.

So I think what we'll try to do is, you will see changes we make to the development plan not -- hopefully not too many, but you know, it'll all depend on what the interim looks like. But we'll try to provide some clarity on it.

However, we won't provide the specific data that's coming out of that interim analysis that will be provided really at the end of the primary observation period -- or end of the study, I should say..

And I could add that the base case scenario for us is that the study is powered to be at the right level for a potential significance between placebo and absolute treatment there. So having to increase the sample size, to a certain extent, is something that will just increase the hopelessness of leads as a Phase 2 study.

But as AJ said, the best case scenario will be really that then we can further increase the sample size to make it one of the pivotal study that we might want to see.

And that will be done in discussion with the FDA, because we can discuss the detailed data with the FDA, which is something that will be important for the next step moving forward there. Now, on the second question, AJ, you like to comment on the new data coming for the OLE..

Sure. And the -- to your question around the timing of the data. Now, as we've been going through this, you've seen that we've provided data, almost like three months up cuts, this point doesn't it doesn't really make sense to keep dribbling that data out.

What we really want to think about is now, what are the meaningful data releases that we're going to have. And what's nice about that second half is it allows us to have a full two year readout on the open-label extension study.

So that's why we're targeting the second half is to give kind of that -- that meaningful two year readout for all the patients..

And we also hope to have some transnational data available by that time from values type of study that we are conducting on the Phase 1a..

Great, super helpful. Thanks, AJ. Thanks, Pascal..

We have our next question coming from the line of Michael DiFiore with Evercore. Your line is open..

Hey, guys. Thanks so much for taking my question and congrats on the progress. Two questions on ATA188, if I may.

One regarding to change of the primary endpoint from sustainability improvement to EDSS, does this change that was mandated by the FDA or preferred, I should say, in any way diminish your confidence in the program given that any benefits in time 25 foot walk that would have -- that would have occurred? And would have been attributed to FDA or not possible? And I have follow-up next..

AJ, you want to take that one?.

Sure. Thanks for the question. It's a good question. Really for us, the good news for us to really throughout the entire Phase 1a program is when you look at the basis of improvement that we saw in sustained disability improvement, the vast majority of it was driven by EDSS.

So from our perspective, it actually doesn't really hurt us at all, in terms of the likelihood of success at the end of the study when we focus just on EDSS. Because, again, all of that improvement, the majority of that improvement was driven by EDSS. We did make a small sample size adjustment issue to the 80 patients.

So you can see it's a very minimal adjustment to account for that change. But our confidence is high. Because whether it was in the main 12 months of study or to the open-label extension, we continue to see EDSS as a driver of improvement..

Great, that is helpful..

And do you have a follow-up question?.

Yes, I do. Second question is regarding the interim analysis for ATA188. It sounds like after the interim analysis occurs, but before enrollment is complete, you're going to have that discussion with the FDA.

What I mean -- what do you think the FDA could be looking for in terms of a treatment EDSS treatment effect in order to kind of support moving forward and expanding the enrollment of the trial to a registrational study?.

AJ?.

I think there's a couple of things that we want, in terms of one of the big things that we need to kind of align on with FDA is the population target here. Because, we are as you know, we've got non-active for Secondary Progressive MS and non-active Primary Progressive MS.

The -- we need to kind of align with FDA; do they want to treat those as separate populations or combined populations? And that's an important piece, because, you know, for us, we're conducting the study. So it really doesn't matter, which way they go, we've got it robust enough so that we can either put them together or keep them separate.

But in terms of the next step, this is where it really comes in. Because once we do the interim analysis, so step one, we expect to align with them over the next couple of months on exactly where they want to go.

Then, when we do the interim analysis, it allows us after the interim analysis to actually apply for an expedited pathway, because the expedited pathway that we're talking about, do require you to have a very specific target population. That's an important step to apply for Express pathway.

But also from a registrational perspective, you have to have that specific population well identified. So, that's one key piece that we're going to be doing between now and the interim analysis.

And to your point, you're asking about what would now make the interim analysis registrational? One, you need that alignment, and then two is you know that that's going to be really just a question of when the interim analysis comes out, and we take a look at those datasets, how the FDA looking at it both in terms of population dynamic, as well as the early results we're seeing on the interim..

Yes. And I will add that, as usual. We will also see like to see of course, a significant difference between placebo and active treatment.

And then the question will also be about the safety database, how many patients would like to see to transform these oldest Phase 2 into the regulatory pivotal trial there? So, that's a different aspect we discuss with the, And that's why we plan that i.e.

before finalizing the enrollment because when we say that, we'll finalize the enrollment in the first half 2022, that's what Phase 2 of the study to then go to pivotal program.

But of course, if the FDA aligns with us, and they say, on one hand, you have significant difference versus placebo, you have good safety on your patient, but they would like to see more patients there.

And at the same time, there is the clarification on the population, then that allows us to expand that study before it's fully enrolled by definition, want to expand it before there. And that's why the timing is very important.

And we have very well organized to really address that particular timing aspect of firstly, IA, then the funding duration of the enrollment, depending on the discussion with the FDA..

Very helpful. Thank you..

We have our next question coming from the line of Anupam Rama with JPMorgan. Your line is open..

Hi, guys. Thanks so much for taking the question. On the ATA188 Phase 1 presentation in the second half, you mentioned a couple of times on this call some translational data that will be presented at the conference, maybe you can give us a little color on what specific translational analyses we should be focused on? Thanks so much..

Thank you Anupam for your question, AJ?.

Yes. So thanks for the question, Anupam. I think, we've got a variety of different translation elements that we've looked at in the Phase 1a study. We’ve mentioned previously that we're working on that assay to detect ATA188 in the serum and CSF and we've conquered kind of the main technological barriers, now we're just looking to validate that assets.

That's one component that we might see. There's other things, as you know in the study that, we had different elements of MRI results and some other biomarkers that we assessed in the Phase 1a study. So, some of those may also be possible to present in the second half. So, right now, we're just putting some of those data together.

And there will be some combination of those elements that we anticipate in the second half..

Thanks so much..

Thank you, Anupam..

We have our next question coming from the line of Salveen Richter with Goldman Sachs. Your line is open..

Good afternoon and thank you for taking our question. This is Elizabeth on for Salveen.

Just wondering if you could talk a little bit more about your commercial readiness plans ahead of the Tab-cel launch in the first half of 2022, what that could look like and then what a sales force might look like there?.

Thank you for your question.

Kristin, do you want to take that question?.

Yes. Thanks for the question. So PTLD as we know is an ultra-rare disease. And so consistent with that, we're really looking at a commercialization approach that's very much in the model of a rare disease model. So that will include a very limited number of highly specialized commercial as well as medical field staff.

And then we will have – we’ll be supplementing that with different sorts of communication, multi-channel, peer-to-peer congress and so forth..

Thank you. And I think what I will add as well is that these patient population of PTLD, first line therapy is very well identified. I mean, these patients have gone for transplants then they have unfortunately been diagnosed with PTLD. They've added their value setting including EBV positivity of PTLD.

Then they get the first line treatment, which could be as you know, rituximab, or rituximab plus chemo, and then really, they’re well identified.

So what's important from a commercialization point of view is that at that time the physicians will be aware of Tab-cel and be able to plan in advance in case the patient does not respond to first line therapy, or is a factor or is relapsing after response the first line therapy, but it can immediately access Tab-cel.

So this ability to identify the patient early on in their pathway is extremely important in the way we're going to commercialize Tab-cel to make it a product that is sufficiently available in a way for the physician, so they know when to act for their patients in the best interest of their patients care.

Does it answer your question, Elizabeth?.

Yes. Thank you..

We have our next question coming from the line of Ernie Rodriguez with Cowen and Co. Your line is open..

Hi. Thank you for taking my call and my question also. Actually, my question is also on the commercialization of Tab-cel.

You mentioned thinking about partnerships for ex-US commercialization, I was wondering if you can add any color to that or what kind of -- what are you focusing on those partnerships -- focus on the indication on a very particular geography or how are you approaching it? Thanks..

Well, thank you for your question.

So in terms of partnering discussion ex-US, we have initiated a number of discussion with interested parties that are really focused or first on Europe, because as you know, we have a very clear line of regulatory pathway in Europe, Jakob Dupont has mentioned and our regular interactions with the reviewer there in Europe.

So we know exactly what is needed there. And we know the timing for submissions now that is planned for Q4 2021. So that means these key regulatory path in order to have a discussion with interested parties, so they get ready to be able to launch Tab-cel in Europe in the second part of 2022.

The type of partner we're looking for, is a partner that has already an infrastructure for commercialization in Europe, around a hematology, transplantation and rare diseases in oncology in general, because that's where this partner could really leverage that infrastructure in creating further value with such transformative therapy that, as you know is a therapy that is much easier to deliver and supply than for example, autologous CAR T because this is truly an off-the-shelf product.

So the partner just add to the commercialization and of course, medical infrastructure there to handle such a product to get access. But the delivery and supply could easily be managed by Atara product partner in this type of geographies.

And in fact, we already have experience of that, because we have opened clinical sites for pivotal study and for the 205 study in Europe, so we already delivering in Europe Tab-cel as we speak to these clinical sites, when there is a patient included into a study.

We've also done conduct a NAAQS [ph] program in Europe, which was to treat patients there. So that experience is really at Atara. And we will be looking for a partner that can prolong that experience into the wellness and commercialization of Tab-cel in Europe.

Beyond Europe it will be really depending on the type of partner we're talking to, because some of them might have interest. We have already experienced in Australia, of course. We are also opening site now in Canada.

So there are a number of geographies where there is already the possibility to treat patients and it might be an interest for partner there as well.

Does it answer your question?.

Yes, very helpful. Thank you..

[Operator Instructions] We have our next question coming from the line of Matt Phipps with William Blair. Your line is open..

Hi. Good afternoon. Thanks for taking my question.

Just you wanted to clarify the discussion with the FDA around the final content for CMC module 3? Is that related to the procedural question on the non-pivotal data? Or is that a separate discussion?.

Thank you Matt for your question.

Jakob?.

Yes, absolutely. So, Matt, thanks for the question. So, in essence, as mentioned, we've had a number of productive discussions with the FDA about module 3, and we want really want to secure responses regarding the module 3 in the guidance for the CMC content of the BLA.

And so with that guidance, we're also going to be receiving the guidance when it comes to the presentation of the historical non-pivotal data. So it's really connected in point of fact, but our key point here is that we want to get that -- secure all of that guidance needed to complete the module 3 for the BLA..

Yes. And I will add to that also that having this alignment with the FDA on the content of module 3 is something very important in advance of the submission to optimize the chance of success in the BLA submission, and the FDA agrees with us.

That's why we are talking in advance and we have this BTD status that was also very frequent and productive interaction with the FDA. In fact, if you think about it, we are the first company coming to the FDA with BLA submission for allogeneic T-cell therapy.

The FDA knows that in fact, we are that are the expert on a product and goal of the ongoing discussion is make sure that we fully align before the submission. And it's not a gating factor, because we know that the gating aspect is more related to the maturity of the clinical data that allows us to be able to finalize the submission into FY 2021.

But all this work, all the progress we are making now are really there to optimize the chance of success in a BLA submission, especially on the CMC aspect of the file.

Does it answer your question?.

Yes, I think so.

And then have you submitted any additional data to the FDA? Because maybe comparability, assays or something like that, since you started having these discussions on the procedural question?.

Yes, when we’re discussing about Module 3, in fact, we are -- it's not only a discussion in principle, it's a discussion based on data. So we are submitting to them data for the typical Type B setting.

We have already had in the last few months two Type B meeting on different topics with them on the CMC file where we find -- we submit to them data, and we discuss about these data. And then how do they want to see the data being presented in the final submission.

So it's not only a conceptual description, it's really a data driven discussion, which I think is very important to make progress here..

Yes. And maybe one other comment there that for each of these interactions, there are formal briefing books that are submitted in advance of those Type B meetings, but they'll even be requests that come from the agency for additional information that we service to our reviewers over at the FDA.

So this is a very rich, very productive, and very frequent engagement that we have with the FDA on this topic.

And even when we are -- what we call informal call the one we have last week, we sent to them in advance really a briefing book with all data analogies and details that we think are important to discuss, even in an informal call, which then is different from the Type B meeting Type B within response there..

Great. Thanks..

We have our next question coming from the line of Maury Raycroft with Jefferies. Your line is open. Maury Raycroft, your line is open, you may ask your question..

Hi, this is Ken Chan on for Maury Raycroft. On 188 whether the current Phase 2 can be used as registration, is there -- what data does the FDA need to accept in a pooled PPMS plus SPMS arm versus running separate trials for the two arms? Thanks..

Thank you for your question.

AJ, you want to take that one?.

Sure. Yes, it's essentially the same data that we're generating. We're generating one set of data that's driven by EDSS as the disability improvement endpoint.

The only question that we're aligning on with them is, what population are we looking at? So we do we say it's a single non-active progressive MS population, which by the way, if you really talk to the thought leaders in the space, that's how they look at this, they think that the progression in this space is identical in both settings.

So, that's what we're issuing for. Or, again, if the FDA decides to look -- say to look at the population separately, they're still going to look at the endpoints in the same exact fashion. So we still need to have separation of ATA188 versus placebo, within whichever population target that they agree to. So there's no difference.

It's just the population piece..

And that's why if I may had what we say that these Phase 2 study, we're running right now the randomized control trial, in fact, adapted to either scenario from our point of view. And that's great, because that's the most worthy discussion of the FDA and then the IA and then to adopt to whatever alignment we have with the FDA there.

Does it answer your question?.

Yes, thanks..

We have our last question coming from the line of Yigal Nochomovitz with Citi. Your line is open..

Hi, this is Carly [ph] on for Yigal. Thanks very much for taking our questions.

For MS can you just talk about how changing the primary endpoint to EDSS impacts the interim analysis if it does at all? And can you just remind us of what triggers the interim analysis, and whether increasing the enrollment means you'll need to enroll more patients to trigger the interim or does that trigger not change? Thank you..

Thank you for your question.

AJ?.

Yes. So the EDSS change does not really impact us at all on the interim analysis. But the goal for the interim analysis is that we've talked about the enrollment target that we have of 80 patients, the way the interim works is, we're really going to do the interim analysis, just before we hit that 80 patient target.

And so the driver is getting close to that enrollment target more so than anything else, because that allows us to have the most profitable data when we do the interim analysis. And then once we -- and then again, once we do the analysis, when you're talking about expansion of the study, again that'll just depend on the numbers that we get.

But Pascal kind of alluded to this before, with a strong Phase 2 a small expansion would be meant to just kind of beef up that statistical target. A large expansion may signal for example, the possibility that FDA says, hey, this could be potentially registration and we want a little bit more safety and a bit more total all numbers for your study.

Does that answer the question?.

Yes, that's helpful. Thank you..

Thank you..

There are no further questions at this time. This then concludes today's conference call. Thank you for your participation. You all may now disconnect..