Good afternoon, ladies and gentlemen. My name is Leah, and I will be your operator on this call. After the presentation, we will conduct a question and answer session. Instructions will be provided at that time. Please note that this call is being recorded today, Wednesday, June 23, 2021 at 2 pm Pacific Time and will be available on the Investors section of Arcus' website at www.arkusbayo.com.
I would now like to turn the meeting over to Katie Bok, Vice President of Investor Relations and Corporate Strategy from Arcus. Please go ahead, ma'am.
Thank you. Hi, everyone. Thank you, Lia, and thank you all for participating in today's call on such short notice. Today, we will be discussing this afternoon's announcement regarding the interim analysis from the ARK7 study. Joining me from ArQA are Terry Rosen, Chief Executive Officer Juan Haiyan, President Jennifer Jarrett, Chief Operating Officer Bill Grossman, Chief Medical Officer and Karthik Krishnan, Senior Vice President of Clinical Development.
I'd like to remind you that on this call, management will make forward looking statements within the meaning of securities laws, Safe Harbor provisions. For example, statements about our clinical development programs, timelines and potential of the Artis Gilead partnership. All statements other than historical facts involve risks and uncertainties that may cause our actual results to differ. Those risks and uncertainties are described in our annual report on Form 10 ks and quarterly report on Form 10 Q, which have been filed with the SEC. We strongly encourage you to review those filings.
This conference call contains time sensitive information and is accurate only as of the live broadcast today, June 23, 2021. And with that, I'll turn the call over to Terry.
Thank you very much, Katie, and thank you all for joining our call today and your interest in Arcus. We really appreciate your engagement. As Katie mentioned, the point of today's call is to discuss our announcement this afternoon regarding the interim analysis from our ongoing ARP7 randomized Phase 2 study. We really recognize the intense focus around this disclosure and I'd have to say we're all genuinely excited to finally have the opportunity to see the data, share assessment of this data set and convey the potential opportunities that they afford us. 1st, I'll spend a few minutes reminding you why we have a digit program, which now includes 2 TIGIT antibodies in the clinic and then we can do a deeper dive into the ARC TENET study and results from the interim analysis.
I'll round up the call with a number of the other exciting things that we're doing here at ARCVIENDS as we continue on our journey towards the coming what we genuinely believe will be a fully integrated commercial biopharmaceutical company. So since our founding only 6 years ago, we've built a robust drug discovery capability to create highly differentiated small molecules. Our small molecule portfolio and focus today include both immuno oncology targets and mechanisms such as ATP's benefit pathway as well as cell intrinsic targets such as 52 alpha and ACTL. However, we also recognized from day 1 the essential need to own important backbone antibodies against PD-one and TIGIT, which we could combine with our small molecules to create and develop rationally designed combination therapies. And so we invested early and heavily to secure access to high quality PD-one and digit antibodies.
Through these efforts, I'm pleased to say that we now have 5 clinical stage modules of which the majority have moved into randomized or registrational trials. We also have another molecule, our HIF-two alpha inhibitor, AB-five twenty one, expected to enter the clinic in the second half of twenty twenty one. This will bring our total clinical stage molecules to 6. We have also built what we believe is one of the best oncology development capabilities in the industry, particularly when you think about a company of our size. And our goal has been to advance our molecules into randomized clinical studies as quickly and efficiently as possible.
And that brings me to TIGIT in our segment. First let me touch on the rationale for TIGIT as a target. TIGIT is an immune checkpoint receptor expressed on immune cells, including T cells and natural killer cells and is typically co expressed with PD-one. Activation of TIGIT by its ligand CD155 results in suppression of these immune cells leading to impairment of antitumor immunity. Clinical studies have shown that the combined inhibition of TIGIT and PD-one results in synergistic antitumor activity.
Most notable in this context were the CityScape Phase 2 data, which showed significantly higher response rate and progression free survival for an anti TIGIT plus anti PD L1 doublet versus the anti PD L1 antibody alone. Early on, we recognized the importance of TIGIT as the next back bone immunotherapy and in licensed our first stitching antibody. At that time, we made the decision to silence the efficacy function. We believe then and continue to believe now that depletion of intratumoral Tregs was not a requirement for the clinical activity of TIGEN antibody. And in fact, that long term depletion of Tregs in the periphery could result in unwanted toxicity.
And that the potential depletion of inter tumor cytotoxic T cells, which are the very same cells that we're trying to reinvigorate could diminish the potential synergy between TIGIT and PD-one antibodies. Consistent with how we pursue all of our programs, shortly after we selected our first anti TIGIT antibody dongmabilumab, which we also we call dong, we initiated work on a second differentiated molecule directed against the same target. We recognize that an Fc functional antibody with the potential to deplete TIGIT positive cells could be beneficial for certain tumor types. More specifically, in solid tumors, HIDGIT is found only on immune cells and not on cancer cells. However, in certain hematological malignancies, the cancer cells actually spread TIGIT.
In this case, depletion of the TIGIT bearing cells will be beneficial. So we recognize the optionality that this provided and specifically designed our second molecule 8,308 to be Fc enabled. And certainly, investment is now paying off. Dom has the potential to be the 2nd or third TIGIT antibody for the market and potentially the first in certain sessions. And we have another anti TIGIT molecule right behind it in Phase 1 combination studies with XAN, and we expect to initiate our 1st expansion cohorts with this regimen later this fall.
We believe it was only company with 2 anti TGA antibodies in clinical development. Before I get to the results of the interim analysis, I really want to step back, take a moment to thank our patients and investigators for participating in the ongoing ARK7 study. As a reminder, we designed this study to target patients with first line metastatic non small cell lung cancer with 50% or greater PD L1 before the release of the CityScape data. The CityScape study utilized a PD L1 antibody and so the results we will discuss today represent the first public discussion of randomized readouts for a TIGIT antibody combined with a PD-one antibody in the study. The ARP-seven study includes 3 arms ZYN, which is our PD-one antibody, ZYN plus DAL, to which I'll refer to doublet and ZYN plus DAM plus etrimum, which is our adenosine 2A2B receptor antagonist, which was previously known as AD928.
I'll refer to this 3rd arm as the triplet. This randomized study has a target total enrollment of 50 patients per arm or 150 total patients. As a reminder, the CDC results in the PD L1 type patient population were based on 29 patients per arm. ARP7 was designed to provide us with a lot of valuable information, notably not just how the doubling performed relative to ZYN alone, but also whether the true month might get efficacy to that doubling. If positive, this triplet combination would allow us to develop a completely novel and differentiated therapy for this patient population.
This arm is really the type of combination that ARTIS is all about, unique and rational differentiation, which creates a potential home run for patients. Let me just give you a reminder that we and our partner Gilead have been blinded to the ArcS7 data. We blinded ourselves to maximize the integrity of the study and to preserve our ability to use this study for regulatory purposes. This first interim analysis, therefore, was designed to provide us with an early look at these data to form our future development decisions for both the doublet and the triplet. Now to the results from this interim analysis.
As you know, we've been very clear that we would not share quantitative data from this interim analysis at this time. This is an ongoing study that is still enrolling and as a result, it is critical that we not disclose data that could potentially bias investigators or impact our ability to complete enrollment in the study. Also, the intent of top line releases is to preserve the ability to present the results in a medical conference, which we obviously want to be able to do. So today, I'll share as much qualitative information as I can. So the initial decision we made based upon the results of the interim analysis is that we and Gilead agreed that both ARK7 and ARK10, which is our registration study for down foot VIM in the same population should continue its plan.
In addition, we and Gilead agreed that the results of this interim analysis support the continuation of our ongoing joint efforts to prepare for additional Phase III studies for DAS. Before diving into further details, I would first like to remind folks, given that this is an early block, clearly the total number of disease available patients in the interim analysis was relatively small and the data still need time to mature in the ongoing study. Also, as with any ongoing clinical study and because this is an early look, the data could change over time. I will now spend a few minutes on each of the arms. The first thing that we wanted to confirm with this study is that ZIM showed activity similar to that of other marketed anti PD-one antibodies in the study.
And in fact, the results today continue to demonstrate that ZIM has activities similar to that of the market anti PD-one antibody. Having our own anti PD-one antibody provides us with a huge amount of optionality. So the performance of this first arm is important observation for both Arcus and Gilead, which shares the rights of this molecule with Arcus. 2nd, we wanted to demonstrate that doublet and triplet provide superior anti tumor activity relative to Zimelone. Both armories with bound based combination showed encouraging clinical activity that Arcus and Gilead believe are sufficient to continue enrolling our existing studies as planned and to continue with our preparations for additional Phase 3 studies.
We're doing that together. In particular, we were intrigued and actually quite excited about the activity seen in the triplin R, which is the 1st data set reported for an anti TIGIT and adenosine receptor antagonist combination. Allowing the data to mature will enable us to better assess the relative contributions of each of DALM and Intrusion. Given the exciting data from the triplets, we look forward to evaluating this regimen in other studies. In summary, we are encouraged by the data we have seen to date in all three arms and particularly the 2 down containing arms.
As we go through clinical studies, we understood there would be a trade off between an early look and data maturity, but we're excited about the data and thrilled that they support the continuation of our ongoing digit development plan and strategy. The opportunities in this space are enormous and our approach is to be thoughtful but expeditious, generating randomized early data on Fermion to support our future investment in both the solid and the triplet is an example of just that mindset. A key observation from this initial data set is that the time to response across all arms is rather long with an average time to response of over 3 months and therefore the study and the data will benefit from greater maturity and more disease assessments. In fact, more than 25% of our responders did not achieve a partial response until after their second tumor scan. We find this extremely encouraging hallmark of the profile and benefits associated with immunotherapy based therapies.
Data from March 7 will be submitted later this year for presentation in the medical meeting. So what does this mean for the Gilead option? The mechanics of the option are such that Gilead has to first determine whether triggering events for an Argus program has been met. If they make this determination upon delivery of the data package, Gilead would have a certain period of time, typically a few months to make a decision. As a reminder, Gilead's guests will chase 1 bite in the ammo for Dom after a triggering event has been met.
Also once they lead to operate their program, they become responsible for 50% of the joint development costs. Since this was a blinded study, when we unveiled the data to the Gilead team, they shared their excitement to continue moving forward, particularly the Dom combinations, including the Triplett given the potential differentiation of this combination. I'm sure they will also communicate this with all of you. However, Gilead has determined they will not start the opt in review period this time. They expect to make a decision on the opt in by year end following maturation of the R7 data to confirm the results that were observed in this interim analysis and to better understand the relative contribution of DAWN and ETRUMA.
Both parties recognize the importance of moving quickly here. This is also why we will continue with our Phase III planning and the timing for the opt in should not slow down 1st patient in for these studies. Since dealing with options also include AB-three zero eight, I wanted to spend a minute on the status of our second kitchen antibody, which is actually advancing very quickly. As a reminder, this molecule is in a Phase 1b study in combination with VIM. This also has the potential to advance into pivotal programs for heme malignancies even if we advance down in solid tumors.
We started this study with 2 important advantages resulting from our extensive clinical experience with PIGIT. 1, we started dose escalation of AB-three zero eight directly in combination with XAMPP and 2, we started at a dose level of AB-three zero eight that we predicted based on our prior studies would be relatively close to the dose level we would want to take forward. And in fact, AB-three zero eight achieved full receptor occupancy in our first dosing cohort. We've already completed enrollment of the 2nd dosing cohort and we expect that the 2nd or third dosing cohorts will likely be our going forward fixed dose for 8,308 and ZYN, put into the position to start our expansion cohorts later this year. Before we leave the Q and A, I want to update you on the other events happening over the next several months.
First off, will be an update on our R8 study for AB680, which is our small molecule CD73 inhibitor in first line metastatic pancreatic cancer expected to be presented in full. The data set will include updated data from the ASCO GI presentation in January from the dose escalation portion of the study and data from the dose expansion. We continue to be very excited about potential of this molecule and what we all know is a truly devastating disease. 2nd, we will be initiating the 1st clinical study for our HIF-two alpha inhibitor, AD521, also in the fall. We also expect to submit ARK7 data for presentation and medical conference by year end.
Last, we are currently evaluating etruum up in 3 different randomized studies. In TKI refractory EGF receptor mutant lung cancer and second line plus colorectal cancer and second and third line metastatic catheter resistant prostate cancer. We look forward to being able to share the data from these studies, which we hope will further validate the potential of etruumab in multiple patient populations. Finally, I wanted to wrap up with an update on our financial position. First of all, we feel we are fundamentally well aligned with Gilead in how we are looking at these programs.
So we think it is unlikely we will advance our programs into registrational studies without the support of our partner. To date, Gilead has made a greater than $650,000,000 total investment into ARGUS through their upfront payment and equity investments, including the 19.5 percent ownership to date, the most recent raise in February. And we believe their commitment to ARKUS is as strong as ever. As a result, we have over $885,000,000 of cash and cash equivalents as of the end of March and plenty of capital to prosecute our programs over the near term. We'll now open up the line to
Your first question comes from the line of Alicia Young from Cantor. Please go ahead.
Hey, guys. Thanks for taking my question and congrats on the moving forward with all three arms. Just I guess the question on everyone's mind is that thinking of obviously the Roche data and your internal bar being around the 50% or so, I'm just curious about how to think about views of competitive views around double and a triple. I mean, does it need to be kind of in that 60s neighborhood to be competitive? And I know you don't want to give numbers, but like anything qualitatively you can do to help us understand like kind of how to stack this up and how you view positioning this asset competitively?
Thanks.
Thank you, Olivia, and thanks for the question. So as we said, we aren't going to get into any quantitative numbers. But first of all, let me remind you a couple of key things. So zembrolumab performed just like the market in the anti PD-one. Both of the combinations met our internal thresholds to continue going forward.
Our data set is relatively small. It's clearly difficult at this point to compare it to the CityTape data. Clearly, we don't have the maturity of that data set yet. But based upon everything that we've seen, we think that our combination of our anti PD-one plus our anti TIGIT is going to look like any of the other anti PD-one anti TIGIT. And we feel that the data that we generated today, if it holds up with the triplet, could offer a clear competitive advantage.
That's part of the reason why we actually are feeling very good about it. Having looked early, it's helping to inform how we think about the proportion of registrational study. Do we actually start to shift toward a greater proportion where we might be taking on the triplets. And we feel like the next several months, given where we are in the study, will actually help to see how that doublet and triplet arm actually end up separating with a little bit more time.
And then just as a follow-up, for the triple, I mean, should we expect some sort of kind of further update there by the end of this year or is it more like kind of in 2022? Because said it takes like 3 or 4 months
it sounded like. Thank you, Rodrigo. So we will present the totality of the data together at that medical conference we were talking about. So full update, both the doublet, the triplet as well as the monotherapy.
Great. Thank you very much.
And your next question comes from the line of Robin Karnauskas from Truist Securities.
Alicia prepped me well. So let me just ask this clear question. So it sounds like what you're saying is that you both both combos met the internal bar for going forward. I think going in, I think I even have written from you all that like 50% or above would be good. And so when people say that encouraging, you use the word encouraging, they're worried that that doesn't mean that 50% bar was met.
Can you make people feel a little bit better about the word encouraging? That's the first question. And then it sounds like this combo, making a statement for the combo is a little bit of a lot more optimistic than even what we were thinking. Maybe give us a little bit more color around, is Gilead looking at that combo as well? And you said that basically they're going to make a decision end of the year.
That means they're going to get data in a few months because they have 2 to 3 months. When will they get that data? Could the opt in go later than that if they have to wait for more data? So I know there's 2 questions there. Basically, make people feel better about the word encouraging.
And second, a little bit more granularity about what that often qualifying mark is? Thanks.
Thank you, Robin. You know how my brain is and that was a little that's a lot of words, but I think I got the totality of your question. So first of all, what does encouraging me? One thing to get that we want to make very clear going along. So during 2020, as we evolve from an independent company working by ourselves to an independent company collaborating with Gilead, we had a number of things that we've been working on from a communication standpoint.
And what I would say is, at this point, we've gotten to a situation where we're being very highly aligned in how we communicate on the same topic. One of the things that we talked about is we don't want to get quantitative about this at this point. With that said, what does encouraging mean? So encouraging reflects a number of things. First of all, that the Zimbrelimab performed as the marketing anti PD-one antibody.
2nd, that both the doublet and the triplet met the hurdles that we've talked about wanting to see for us to go forward. Over the course of the year, we've used the metaphor, thumbs up, thumbs down. Gilead has communicated these data to give us a thumbs up. We want to pursue as we planned. We're continuing the planning with our trials.
To your point about the triplet and how should we contextualize the triplet based upon what we already just said about the doublet. Our look, we believe, is similar to Gilead. And that's why we're looking to have this additional few month period. If those data continue to hold up, I believe that Gilead shares our enthusiasm that the triplet could represent a truly differentiated opportunity from the other doublets that the rest of the world is pursuing.
Quick follow-up if I can. So for 3 0.8, a lot of questions obviously going into this around FC enabled versus FC Notch. But your decision to continue on with this trial and continue on with a pivotal trial have anything to do with that the current drug is sufficient, you don't need FC enabled? Or how do we view the FC enabled versus FC not debate? Can we learn anything from this press release?
And then I'm done, sorry. Thanks.
Sure. No, thank you, Robert. One thing I should really make a point because maybe this helps with both yours and Olivia's question. One of the other things we talked about is that we weren't simply looking at a single numerical number. We've really looked at the totality there.
For example, the spider class, I mentioned the time to response. Virtually all of the patients by far the vast majority in both the doublet and the triplet remain on study. So all of that encourages us as to how things will play out with greater data maturity. Coming back to the 3 0 8 question, you should keep in mind that's exactly the same way we've been positioning that for ages. Basically, we've been moving it along, recognize the opportunity that and the optionality that it provides us in certain other settings and hematological malignancies and we're going to be very aggressive about that.
In fact, the data and the speed of which that's enrolling is awesome for us and we're excited to have both of those. In terms of FC versus non FC, I think we'll start to switch the narrative or at least from coming out of our mouth on that question. As you know, it's something that probably is never going to be proven unless someone literally runs an anti TIGIT plus the same anti PDX side by side. So based upon the totality of the data that we've seen today, we feel we have an anti TIGIT antibody that looks like an anti TIGIT antibody. We don't expect there to be any differences between the Fc or non Fc function.
Thank you, guys. I appreciate you taking all the questions and congrats on hitting this milestone.
And your next question comes from the line of Umer Raffat from Evercore ISI. Your line is open.
Hi, guys. Thanks so much for taking my questions. Maybe three quick things, if I may. First, I know there's a lot of focus on the 50% threshold for the combo arm. Let me go to the other side of the spectrum on the PD-one monotherapy.
And I feel like there's a fair amount of spread even for the commercially marketed PD-1s. For example, 227 for Opdivo is in the high-30s, whereas KEYTRUDA in QNO24 is in the mid 40s. And as we think about those two numbers in the context of 50%, that makes one of them look like only a 5% spread versus combo, the other one looks like a double digit spread versus the combo. So I'm trying to interpret that in the context of Terry, how you described the doublet being sufficient to continue and triplet being something you were intrigued and excited about. I would really appreciate any thoughts there.
And then if you could also remind us what the median duration of follow-up is? Thank you very much.
Thanks so much, Amarna. I'm actually going to let Bill Grossman take the question.
Hi, Amaron. Thanks for the question. As you can refer to, there are a number of different things out there for model PD-one and PD L1 and PD L1 population. If you look at the majority of those studies, primarily KEYNOTE-forty two, IMpower-one hundred and ten as well as CheckMate 227, the range really is much closer, I believe. I think it's really in the 35% to 40% range.
KEYNOTE-twenty four did have a higher response range around 45%, but we think we're right in the typical range of all our PDX antibodies out there. So our performance is right in line with what we hoped and we were hoping that we wouldn't see necessarily an underperformance in a patient population, which was not the case so far.
And your next question comes from the line of Geoffrey Porges from SVB Leerink. Your line is open.
Hey,
guys. This is Nafan on for Geoff. Congratulations on the progress. So are the study responses confirmed responses? And are the investigator assessed or independently verified?
And then a follow-up is, what is the longest duration of response in the combination arm? Thanks.
So I'm going to let Doug Rosman handle those questions as well.
Yes. So right now, we're just primarily looking at unconfirmed response rates and they're based off of investigator assessments right now. We will be looking at with longer follow-up and to be confirming all those responses. As Terry mentioned, it's early days in the follow-up period. So we will be looking that as well.
And your last question was around the response. Is that correct, the longest responder?
Yes, the longest response.
Yes, longest response.
And the combination arm.
Correct. Yes. So without getting the numbers between the 2 different combinations arms along with durable response we have is right around 8 months at this time.
Thank you. That's very helpful.
And your next question comes from the line of Salveen Richter from Goldman Sachs. Your line is
open. Good afternoon. Thanks for taking my question. Could you just help us understand what the gating factors are for Gilead to opt in here in this program?
Yes. Thanks, Salveen. I think obviously you won't have a chance to ask them. But I think that part of this is they have the opportunity to let the data mature a little bit more. They're able to do it.
If you ask me, it's actually smart. The data looks quite encouraging to us, but I think that they find it valuable when you look at how these data are playing out as we talked about the time to respond, the spider class, it gives them a few more months to just see if everything holds up the way things are
looking today.
Great. Thank you.
And your next question comes from the line of Mara Goldstein from Mizuho. Your line is open.
Great. Thanks so much for taking the question. Just, I had a question just on the A, the presentation of data and where you anticipate that may occur as we're close to the second half of the year and much of the clinical bigger clinical conferences are really coming up very quickly. And then secondarily, I'm just curious, given that you're approaching that Phase 2 dose in ARK three zero eight, it appears. By the time you round out the year and have a data package for Gilead, with DALM, where will you be with the three zero eight study?
Bill,
you can probably handle both of those
Yes. For the first question, the medical confidence is still to be determined. Once we get more data maturity, the plan has to submit an abstract by the end of the year. As you point out, there is not that many conferences towards the end of the year, but we'll be looking at our opportunities for presentation at the end of the year once we see the data the next data cut. And then as far as like AD308 package, as we mentioned as Trey mentioned, we're in our 3rd cohort for dose expansion.
Right now, we do expect either the 2nd or third cohort expansion to be our recommended dose for expansion to go forward. We are exploring additional flat dosing combinations in that study as well as the expansion cohorts. And then we'll be looking at presenting that study again at that amount of confidence as soon as we can in the near future.
Okay. And if I could just also ask, just on the doublet versus the triplet combination, and I understand you're not necessarily giving specific data. But could you maybe help us understand what you are seeing in terms of inflection differential between those 2 different arms?
So all I would say at this point is that both look very interesting, but the triplet certainly looked like it was doing something more. And we think we simply will with a few months more data maturity, it also bring in not only more data, but more patients that will help us to ascertain whether and how meaningful that difference is.
Okay. All right.
Thanks. I appreciate it.
Thank you, Mark.
And your next question comes from the line of Yigal Nochomovitz from Citigroup. Your line is open.
Hi, thank you very much. Just following on the last question, Terry, regarding the Doubler versus the Triple. I know you're not giving numbers out. But can you please confirm or sorry, can you confirm that the sub the doublet and the singlet was comparable in terms of the separation rather the separation between the triplet and the doublet. Did you see a similar separation there between triplet and doublet and doublet and singlet?
We don't want to get into specific quantitative numbers, but certainly there was a separation from both the Dublin and the triplets were separated from the same lift.
Okay. And then another question, just you mentioned that the time to response was over 3 months for all the arms and that the study would benefit from greater duration. And then you said that 25% didn't respond to the 2nd scan. I'm just wondering if there was a slower if the time to response for the triplet was in fact a little faster than the doublet?
I think it's way too early and way too few patients to start to make those type of comparisons. I would just say if you look at the spider class, they look like you would expect for a immunotherapeutic regimen, too early to try to call out differentials.
Okay, thanks.
Thank you, Vikas.
And your next question comes from the line of Peter Lawson from Barclays. Your line is open.
Hey, thanks for taking the questions. Just as we think about the data being presented, that be presented ahead of Gilead's opt in or would the Gilead opt in delayed data presentation?
We probably can't get that granular with any knowledge we even have about exactly how that's going to play out. So I would just say that we don't have any enough fidelity to make a call on that. Thanks, JP.
Thank you. And then could you remind us about the opt in time and events for Gilead around adenosine?
I'll let Jen know that one.
Yes. So we have not disclosed what the trigger for these amnestine programs are nor are we. And then I just want to come back to Salvi's question as well that also related to the option for TIGIT, it's patient number based. So we have not disclosed what that is. It's been adapted in the agreement, But it's patient number based.
It's not based on the need for efficacy pre emerge or anything along those lines.
Got you. And then just final question just around the spider plots. Do they look encouraging, pointing downwards? Or is there any kind of worry around the
Wonderful, Peter. The Spider Plus and that's one of the things we talked about is we're talking last year that we got to ask sort of qualitative question on the data. That's why we're excited. The spider plot are the telling story and the pattern is very, very, very consistent. That's why we mentioned so many patients remain on study.
That gives you how those butterflies are looking today. Give it a few more months, Ryan, I think they're going to look pretty beautiful.
Perfect. Thanks so much. Congrats.
Thank you, Steven.
And your next question comes from the line of Sis Yang Hsu from Berenberg. Your line is
Congrats on the progress. I have a few questions to have. First is, can you comment on the PFS? I know it's probably immature, but have you seen similar data around 5 months, 6 months as compared to CityScape? And the second question is around the safety.
I think, Terry, in your prepared remarks, you mentioned without depleting Tregs, you may have better safety profile, I guess. Have you noticed any better safety profiles compared to other Fc enabled TIGER antibody? And the third question, I think I want to get a bit more clarity on the opting options on Gilead. I wonder the decision for them to delay to make decision to opt in, would that be associated with the fact that they want to see more data from your 3 0 8 data package given these 2 modules are bundled? Thank you.
Well, thank you very much for those questions. So I'm going to let Bill answer the PFS and safety questions and then I'll comment on the opposite.
Yes, Andy. So from a PFS perspective, Yes, Andy. So from a PFS perspective, that's the time to event endpoint that we have as part of our co primary study. However, at the current maturity data, we don't have PFS data. So that will be forthcoming as the study matures with further enrollment as well.
So no PFS at this time. As far as safety, again, reiterating what Terry had said before, there's no unexpected safety signals across the unit three arms. The current safety profile really appears consistent with all the known checkpoint inhibitors or combinations that have been presented to date for TIGIT antibodies. So we haven't seen anything that is unexpected across all of the matters.
So coming back to the offline question, actually I'd like to frame that. So interestingly, this is not actually a delay in the opt in and in fact what this is would have been like an early opt in. And so Gilead has the time to look, It's smart. It shouldn't be interpreted at all in the context of AB-three zero eight. So I think Gilead and us are both motivated to go as fast as possible.
I should point out that the way this is all staged and how the timing works out is that both the ongoing studies and our planning, it won't be affected by when if they choose to opt in prior to the end of this year, it won't slow us down in anything that we're either doing or planning.
Great. Thank you very much.
Thank you.
And your last question and your next question comes from the line of Jonathan Miller from Evercore ISI. Your line is open.
Hi, guys. Thanks so much for taking the question. You mentioned a couple of times that the data is not mature enough to get a real sense of some very important metrics and that we should wait for that data to mature. That makes sense. When we see this data at a medical metering later this year, at that point, do you expect to have enough follow-up to the giving us not just detailed ORR estimates, but to have a meaningful sense of PFS curves and separation there as well?
Yes. It's a little bit hard to say is a little TBD, but from a PFS perspective, probably not. If you look at the City's case data, they're on the 6 month mark, which I think is where we need to be across all of our enrolled patients. But we will be able to at least express and show information on some of the durability of the responders. And so that type of data will be able to definitely include in the presentation around our response rates.
Great. And at that point, just of course, obviously, this depends on enrollment and follow-up, but about how many patients would you hope to have by that medical meeting later this year?
So we make sure we're not actually disclosing anything quantitative about enrollment, but I'll tell you that the study is enrolling quite well. We've got over 60 sites up, it's doing well.
Okay. Thank you so much.
And you have a follow-up question from Robyn Karnauskas from Chuvreux Securities. Your line is open.
Hi. Sorry to ask another one. Two questions. Just think about the competitive landscape, you've got a lot of people going after TIGIT. How much of your press release and lack of color is given around the thought to other people reading the data?
And second, you've got a lot of catalysts for adenosine in the back half of the year. Could you set the bar for people who don't seem to give much credit to adenosine? What would be the bar for the next readout you have for adenosine and why people should care about that data set? Thanks.
Sure. So certainly there are elements of keeping things a little tighter now due to the competitive nature of things. We feel we need to give qualitatively, let the world understand what we're seeing. But I think we recognize this is a quite competitive field and particularly as you start to think about these differentiators like a triplet that start to move you away from just how fast you can execute on a doublet in a given setting. I'll remind you that's what we've been saying all along is the unique aspects of ARKUS.
And so we want to get the color as to what we're seeing, but we will be a little tighter on that information. I also think maybe James can comment a little bit on how the rest of the year is going to play out in the far as the advancing programs, which by the way, we're extraordinarily excited about those. And in fact, that we've been saying for ages, the triplet is a key aspect of what we were interested in. And so I think it's a very logical juxtaposition of question. So thank you, Robin.
Appreciate your question.
Yes. So the most likely net data will be the ARC-eight update. So that's for 8,680, crystal molecule CD73 units that are in first line pancreatic cancer. So we submitted an abstract presentation at a conference. So we hope that will be in the fall.
That's something we're very excited about. As I think we've mentioned in the past about the start of the second line cohort in that study sort of continuing to what we started with our date. But that will be more mature data set for both the dose escalation data was presented earlier as well as the initial data from the expansion cohort. So that will be 20 plus patients in that expansion cohort. We also hope to have, as we talked about by the end of the year, the presentation of the ARK7 data at a medical conference.
So that will include data on the triple arm, which I think we try to convey today we're very excited about. So this will be the big events for the remainder of the year. And then the first half of next year we should have randomized data from all of the studies that Gary pointed out particularly ARP6 which is a study evaluating the tumor and metastatic prostate cancer which we're very excited about that would be randomized data and again, randomized data again for echturma plus chemo and BDFR positive lung cancer.
And your last question comes And your last question comes from the line of Mara Golston, a follow-up question from Mizuho. Your line is open.
Thanks. Just quickly, one of of the things that you guys have said is that the ability to do this interim allows you to make any adjustments to ARC10. And I'm just curious as to at this early juncture whether or not you've learned anything that has prompted you to revisit any of your assumptions?
Thanks, Marshall. That's an easy answer. Our plan is proceeding just as planned. The one thing that I would like to highlight though, because I think it's an important aspect of this, this took on a very public and external flavor as we went through the year. But as we always talked about, this was intended as an internal decision making enhancing tool.
And in fact, probably the biggest thing that came out of it for us, taking that early look is helping us think about what we might do differently insofar as the doublet versus triplet. You can imagine we were in full planning mode on a number of doublets. We're still continuing that, but we're building into the planning the possibility that we may shift just how we think about doublets versus potential triplets and when we might start to execute on those pending the data holding up is to get more mature.
Okay. Thanks. I appreciate it.
Thanks so much, Amaro.
And these are all the questions we have. Please continue.
So let me just thank everybody on the call again for joining. We really appreciate your continued interest and all of the awesome questions. So we look forward to maintaining dialogue. Thank you.
And this concludes today's conference call. Thank you for participating. You may now disconnect.