アキュメン・ファーマシューティカルズ（ABOS）2026年第2四半期決算説明会：ALTITUDE-ADの結果発表は2026年後半を予定

アキュメン・ファーマシューティカルズ（NASDAQ: ABOS）の2026年第2四半期決算説明会は、サビルネツグの第II相ALTITUDE-AD試験の次回データ発表を中心に進められました。また同社は、現金および有価証券として1億1,020万ドルを保有していることを報告し、経営陣はこれにより2027年初頭まで現在の事業活動を賄えると見込んでいます。

主要ハイライト

• アキュメンは、第II相ALTITUDE-AD試験のトップライン結果の発表時期を、引き続き2026年後半と見込んでいます。
• トップラインデータセットには、主要評価項目であるiADRSをはじめ、CDR-SB、安全性およびARIAの発現率、体液・画像バイオマーカーが含まれる見通しです。
• 第2四半期の研究開発（R&D）費は2,780万ドル、一般管理（G&A）費は470万ドルでした。純損失は合計で3,270万ドルとなりました。
• 2026年6月30日時点の現金および有価証券は1億1,020万ドルで、2027年初頭までの事業継続資金（ランウェイ）が確保される見込みです。
• 非ヒト霊長類において、ACU401は未改変のACU234と比較して前頭葉皮質への曝露量が最大40倍に達しました。アキュメンは、最有力である脳移行性向上（EBD）候補化合物について、2027年半ばの治験申請（IND）提出を目標に掲げ続けています。
• 第II相試験のデータ発表に先立ち、サビルネツグ、EBDプログラム、およびアキュメンの投資理論を説明するバーチャルIRデーが9月16日に予定されています。

主要財務データ

事業および運営実績

ALTITUDE-AD試験が重大な第II相カタリストの時期に接近

ALTITUDE-AD試験では、プラセボを対照としてサビルネツグ（35 mg/kgおよび50 mg/kg）の18ヶ月間にわたる評価を行っています。どちらの有効用量も、これまでに薬力学的ターゲット結合が示された曝露範囲内にあります。

主要な臨床有効性評価項目は、認知機能および日常生活動作の評価を統合した複合指標であるiADRSです。経営陣は、2026年後半のトップライン発表には、CDR-SB、有害事象、ARIA発生率、ならびに体液および画像バイオマーカーも含まれる見込みであるとしています。

アキュメンは、第I相試験において3回投与後にアミロイドβオリゴマーへのターゲット結合とバイオマーカーの変化が実証されたと発表しました。サビルネツグは可溶性アミロイドβオリゴマーを選択的に標的とし、IgG1抗体よりもエフェクター機能が低いIgG2抗体フォーマットを採用しているため、差別化されたベネフィット・リスク・プロファイルを提供できると経営陣は考えています。

脳移行性向上（EBD）パイプラインの進展

アキュメンは、JCRファーマとの共同研究のもと、脳移行性向上（EBD）の候補化合物としてACU301およびACU401を選定しました。ACU301にはサビルネツグが採用されており、ACU401には次世代のオリゴマー選択的抗体であるACU234が採用されています。

非ヒト霊長類において、試験された3つのEBD二重特異性抗体すべてが未改変のACU234よりも高い脳内曝露量を達成しました。ACU401は前頭葉皮質において最大40倍の曝露量をもたらし、脳深部における曝露量の増加、可溶性アミロイドβオリゴマーに対する選択性の維持、および問題のない血液学的プロファイルを示しました。

同社は両候補化合物の研究を続けていますが、総合的に最も優れたプロファイルに基づき、いずれか一方を臨床開発へ進める予定です。候補化合物の最適化には、トランスフェリン受容体への親和性、単価（1価）対2価のフォーマット、脳内輸送、および貧血のリスクの可能性などが含まれます。

経営陣の見通し

• ALTITUDE-AD試験のトップライン結果は、引き続き2026年後半に見込まれています。
• アキュメンは、現在の手元資金により2027年初頭まで臨床および事業活動を継続できると見込んでいます。
• 同社は、最有力EBD候補化合物の治験申請（IND）提出時期を2027年半ばと引き続き見込んでいます。
• 経営陣は、第II相試験の成功後に期間を短縮できるよう、第III相試験に向けた準備活動を進めています。なお、第III相試験デザインに関する最終的な規制対応作業は、ALTITUDE-ADのデータに依存します。

リスクおよび注視すべき点

• アキュメンは、ALTITUDE-AD試験の2つの有効用量群における詳細な統計的検定力や分析上の前提条件を開示していません。経営陣は、両用量ともに有効性が示される可能性があると述べています。
• 同社への投資判断は、臨床的有効性、安全性、ARIA発生率、バイオマーカーの知見を含む、2026年後半の第II相試験のデータ発表に引き続き大きく依存しています。
• ACU301とACU401のどちらを選定するかは確定しておらず、初期臨床試験の設計についても協議が続いています。
• 経営陣は、EBDプログラムを健康成人被験者から開始するか、それとも直接患者を対象に開始するかについて決定していませんが、実用的な範囲でできるだけ早く患者への投与を開始することを目指しています。
• デジタルツイン解析やMTBR-tau243などの新しいバイオマーカーは依然として探索的な位置づけであり、初期段階では保管サンプルを用いて事後的に評価される可能性があります。

アナリスト質疑応答の要点

• ALTITUDE-AD試験のデータ発表： 経営陣は、トップライン結果には主要評価項目だけでなく、iADRS、CDR-SB、体液および画像バイオマーカー、安全性指標が含まれる予定であることを確認しました。
• 第III相試験の準備状況： アキュメンはCMC、パートナーとの協議、施設関連の計画を進めていますが、第III相デザインに関する最終的な規制当局との対話は第II相試験の結果次第となります。同社は、良好な結果が得られれば、単一の検証的第III相試験をサポートできる可能性があると期待しています。
• 安全性の差別化： 経営陣は、サビルネツグのオリゴマー選択性とIgG2フォーマットが免疫活性化を抑え、差別化されたARIAプロファイルをもたらす潜在的な要因として強調しましたが、その確認はALTITUDE-AD試験の結果次第となります。
• バイオマーカー： p-tau217は患者スクリーニングに使用され、評価項目としても評価される予定です。保管された血漿サンプルにより、後日MTBR-tau243やその他の新しい血液バイオマーカーの解析が可能になる可能性があります。
• デジタルツイン： Unlearn.AIとの共同研究は探索的評価項目として活用されており、患者選定への応用の可能性や、今後の解析における予後共変量としての評価が行われています。
• 併用戦略： 経営陣は併用療法をアルツハイマー病における長期的な方向性になり得ると捉えており、アミロイドβオリゴマーのポートフォリオと並行して、タウ標的アプローチや抗炎症アプローチを取り入れる機会を評価していく予定です。

決算説明会文字起こし全文

決算説明会の完全なトランスクリプト

経営陣による説明

Operator

Good day, and welcome to the Acumen Pharmaceuticals Second Quarter 2026 Conference Call and Webcast. [Operator Instructions] Please note this call is being recorded.

I would like to turn the call over to Alex Braun, Head of Investor Relations. Please go ahead.

Alex Braun

Thanks, Michelle. Good morning, and welcome to the Acumen conference call to discuss our business update and financial results for the quarter ended June 30, 2026. With me today are Dan O'Connell, our Chief Executive Officer, and Matt Zuga, our CFO and Chief Business Officer. They will have brief prepared remarks, and then we'll open the call for questions. Joining for the Q&A session, we also have Dr. Jim Doherty, our President and Chief Development Officer, and Dr. Eric Siemers, our Chief Medical Officer.

Before we begin, we encourage listeners to go to the Investors section of the Acumen website to find our press release issued this morning that we'll discuss today. Please note that during today's conference call, we may make forward-looking statements within the meaning of the federal securities laws, including statements concerning our financial outlook and expected business plans. You will see Slide 2 of our corporate presentation, our press release issued this morning, and our most recent annual and quarterly reports filed with the SEC for important risk factors that could cause our actual results to differ materially from those expressed or implied in the forward-looking statements. We undertake no obligation to update or revise the information provided on this call or in the accompanying presentation as a result of new information or future results or developments.

So with that, I'll turn the call over to Dan.

Daniel O'Connell

Great. Thanks, Alex. Good morning, everyone, and thanks for joining us today. During the second quarter, our focus remained on disciplined execution as we advanced sabirnetug towards the highly anticipated topline readout from our Phase II ALTITUDE-AD trial, which we continue to expect late this year. We believe this will be an important efficacy readout in the Alzheimer's field. ALTITUDE-AD remains a critical test of our central scientific thesis that selectively targeting synaptotoxic amyloid-beta oligomers may offer a differentiated approach to treating Alzheimer's disease. A substantial body of evidence supports this hypothesis, and we are excited by the opportunity to evaluate that thesis in a well-powered, randomized Phase II study with clinically meaningful endpoints.

Our Phase II results have the potential to substantially expand on our Phase I results, which included demonstration of A-beta oligomer t arget engagement and biomarker changes that we're seeing as early as 3 months of treatment, as we previously reported. We continue to be encouraged with the engagement of patients, caregivers, investigators, and study sites participating in ALTITUDE-AD, as well as in its 12-month open-label extension study. Their commitment has been instrumental in bringing us to this important inflection point. I believe the strong relationships the Acumen team holds with study sites and investigators is particularly supported by Acumen's patient-centric approach.

At AAIC last month in London, we presented patient experience data collected from participants and study partners prior to treatment in ALTITUDE-AD. Results illustrate the diverse ways individuals with early Alzheimer's disease experience, respond to, and cope with cognitive and functional changes, underscoring the importance of capturing patient experience directly to better understand the meaningful benefit at this stage of disease. As we previously described, ALTITUDE-AD was designed to detect a statistically significant difference on its primary clinical efficacy endpoint, iADRS, after 18 months of treatment with sabirnetug compared with placebo. We expect the topline dataset to include results from the primary endpoint, key secondary measures such as the CDR-SB, safety assessments including adverse events and ARIA rates, as well as important fluid and imaging biomarkers.

The study is evaluating two dose levels, 35 mg/kg and 50 mg/kg, compared with placebo. Both these dose levels are within the exposure range previously shown to achieve pharmacodynamic target engagement. While we remain focused on execution and preparation for the readout, enthusiasm across the organization continues to build as we approach this landmark catalyst. We believe that sabirnetug has the potential to demonstrate a differentiated benefit-to-risk profile given its unique product attributes as an anti-A-beta oligomer IgG2 monoclonal. We look forward to sharing the results later this year.

In the second quarter, we announced the nomination of two enhanced brain delivery candidates for the treatment of Alzheimer's disease, representing the only program combining a validated blood-brain barrier penetrating technology with an anti-A-beta oligomer-selective therapeutic antibody. Building on robust preclinical data from both in vitro and in vivo studies, we exercised our options with JCR Pharmaceuticals and will advance two candidates, ACU301 and ACU401. ACU301 is a bispecific antibody incorporating sabirnetug, and ACU401 incorporates a novel next-generation A-beta oligomer-selective antibody with differentiated properties. This is known as ACU234. We view our EBD program as expanding the optionality in our pipeline and will continue to evaluate both candidates in the lead-up to support a filing of an IND. Confirming our mouse data in non-human primates is a pivotal step in this work.

At last month's AAIC conference, we presented data showing that after intravenous dosing, all three EBD bispecific antibodies achieve greater brain exposure than unmodified ACU234 alone. ACU401, in particular, achieved up to a 40-fold greater frontal cortex exposure in non-human primates and significant increase in exposures in deep brain regions. The degree of brain penetration observed in cynomolgus monkeys, combined with preserved soluble A-beta oligomer selectivity and a clean hematological profile, exceeded our expectations and gives us confidence in the differentiated potential of our EBD program's approach. We continue to anticipate an IND filing for our lead EBD candidate in mid-2027.

Coming up, I'd like to flag for investors an anticipated virtual Investor Relations Day to be held on September 16. Please mark your calendars to view live or as a recording, as we hope this will be a helpful review for the Acumen investment thesis prior to ALTITUDE-ADPhase II data readout. The advance of sabirnetug and our next-generation blood-brain barrier EBD candidates underscores the strength of both our scientific platform and our ability to execute, positioning us well for a significant, eventful remainder of 2026. I look forward to updating you on our program and on our Phase II results for sabirnetug late this year.

And with that, I'll turn the call over to Matt.

Matt Zuga

Thank you, Dan. As a reminder, our second quarter of 2026 financial results are available in the press release we issued this morning, and in our 10-Q we will file later today. We ended the second quarter with $110.2 million in cash and marketable securities on our balance sheet, which is expected to support our current clinical and operational activities into early 2027. R&D expenses were $27.8 million in the second quarter. The decrease over the prior year was primarily due to reductions in manufacturing and materials costs as well as CRO costs as we get into the final leg of our clinical trial.

G&A expenses were $4.7 million in the second quarter, roughly flat for the same period in the prior year. This led to a loss from operations of $32.6 million and a net loss of $32.7 million in the second quarter. We are confident in our scientific innovation and strong track record of execution as we work toward our Phase II ALTITUDE-AD readout later this year and advance our EBD program. We remain dedicated to building value with our portfolio of A-beta oligomer-targeted antibodies for Alzheimer's patients, caregivers, and stakeholders.

And with that, you can open the call for Q&A. Operator?

Operator

[Operator Instructions] Our first question comes from Paul Matteis with Stifel.

質疑応答

Matthew Ryan Tan

This is Matthew on for Paul. I guess another company doing an oligomer-specific approach read out some blinded data recently. Maybe can you talk about like what are the differences between their approach versus yours and trial design, and how much can we, you know, kind of read through on their clean safety to your upcoming data?

Daniel O'Connell

Hey, Matthew, thanks for the question. Yes, we saw the announcement of the blinded interim assessment, but this is really early-stage data. So there's not too much we can conclude from that reporting or that announcement. And we'll be interested to see how that study reads out sometime early next year. We reported Phase I results in 2023, which, to our view, established a really robust clinical target engagement of A-beta oligomers. And with just 3 doses in that Phase I study, we're seeing effects on both fluid and imaging biomarkers that sort of exceeded our expectations and underpin our confidence in why in a large study, in an efficacy-based study such as ALTITUDE-AD, sabirnetug is positioned for success.

Matthew Ryan Tan

Okay. And maybe a quick follow-up. In the selection of your EBD candidates, what were the parameters that you sought to optimize? And where do you think your second molecule might be better than the bispecific sabirnetug?

Daniel O'Connell

Thanks. I can quickly comment. I mean, I think for our EBD program, we envision from a product profile standpoint, subcutaneous administration as a convenient form for delivery, as well as preserving the oligomer selectivity, potentially enhancing that selectivity, and an efficient transport across the blood-brain barrier using the transferrin carrier technology as partnered with JCR. So I think we're looking at safety, efficacy, and broader exposure in a format that would lend itself to convenient sub-Q dosing. So both of the candidates have, at least so far, demonstrated all of those attributes, and some of that data has been presented at meetings, and we'll continue to report on findings in that program as we march towards an IND filing on a lead sometime in mid-'27.

James Doherty

Matthew, this is Jim. Maybe I can add a little bit to what Dan has been saying. Of course, when you see the candidates that we announced, those represent the sort of culmination of a process. And we had a really robust collaboration with JCR. And what it allowed us to do is really look at a bunch of different parameters for optimizing for the right fit to match the carrier and the cargo to come up with the final product. And so we looked at a number of things. We looked at affinity for TfR. We looked at valency, monovalent versus divalent. We looked at a bunch of parameters around the potential risk for anemia and things like that. And so it really represents the culmination of a whole campaign to optimize for what we think is the best fit to deliver these oligomer-targeting antibodies into the CNS.

Operator

Our next question comes from Jason Zemansky with Bank of America.

Jason Zemansky

You described ALTITUDE, I guess, as designed to detect a stat-sig difference in iADRS, but with two active doses, can you clarify the framework and whether each dose is independently powered against placebo? If only one succeeds, under what circumstances would constitute a statistically robust positive study? And then a quick follow-up, please.

Daniel O'Connell

Thanks, Jason. Good question. As we have not specifically provided details on the powering and the analysis. I think, I don't know that we can go into greater detail on that this morning. Yes, we do have both doses, both of which have demonstrated target engagement. We think both of these doses could emerge as efficacious doses, and we'll be looking forward to providing more information as we get closer to the data readout later this year.

Jason Zemansky

Got it. And then maybe without getting too much into the efficacy bar, can you speak to the work you're doing now to minimize the interval between the Phase II results and the initiation of a Phase III? Any regulatory engagements, CMC, partner discussions, site planning? Which activities are sort of gated until the data?

Daniel O'Connell

Thanks, Jason. Well, you can imagine there are elements of everything that you mentioned that are ongoing now, with the exception perhaps of regulatory interactions in terms of establishing the Phase III design and so forth. But there's a lot of activity and anticipation to minimizing the white space. And we're hopeful for a successful readout in ALTITUDE-ADthat really will help facilitate and accelerate our ability to move sabirnetug into a single pivotal Phase III.

Operator

Our next question comes from Pete Stavropoulos with Cantor.

Samantha Schaeffer

Hi, this is Samantha on the line for Pete. My first question is there are biomarker data that suggests certain tau fragments like p-tau217 can be used as a marker for amyloid pathology, while markers like MTBR-tau243 identifies tau tangle pathology in Alzheimer's disease. I know that you've incorporated and will look at p-tau217 in the ALTITUDE-ADstudy, but can you talk about tau243? Do you plan to look at it in ALTITUDE, and how could you incorporate it into a Phase III? Can it be leveraged to help or expedite patient selection?

Daniel O'Connell

Thanks, Samantha. Go ahead, Eric.

Eric Siemers

Yes, so this is Eric Siemers. Maybe I can take that one. So, yes, the biomarker world in Alzheimer's is moving really quickly, especially with regard to blood-based biomarkers. As I think you probably know we use p-tau217 as part of our screening procedure actually for enrolling people into ALTITUDE, but it'll also be an outcome measure that we'll look at after we're unblinded at the end of the study.

MTBR is relatively newer, and so it really wasn't being discussed at the time we designed ALTITUDE. But one of the things that we have talked about is that, we have, a large number of patients and a lot of actually plasma samples that will be stored. And so we have the opportunity to look at things like MTBR, new biomarkers that, especially the blood-based biomarkers, that become interesting after we actually complete the study.

So yes, MTBR is one of the things we talk about, but I think it's not just that. Any other new blood-based biomarker that may look interesting, we'll have the opportunity to look at.

James Doherty

And Samantha, this is Jim. Maybe just to add a little bit onto what Eric is saying. I think he's totally right. It's really an exciting time in the field for looking at these fluid-based biomarkers. And the reason for that is it really provides a lot of information about patients. And so I think what we're seeing is people are beginning to measure these multiple markers in a lot of different studies, looking at a lot of different things. It potentially gives you the opportunity to look at where a person is in their progression with disease. It has the ultimate potential, I think, to start identifying patients who might be better candidates than others.

I think we're too early days for those kinds of applications, but I do think that's where the field is going. And so what we'll do exactly as Eric is saying, is as we go along, we'll continue to monitor all this. We'll use these tools as we can in our trials, and we have the opportunity to go back and measure some of these things, even in a post hoc fashion. So I think this is going to continue to be an important part of Alzheimer's trials moving forward.

Samantha Schaeffer

Awesome. And just one quick follow-up. In July, there was an announcement of a collaboration with Unlearn utilizing digital twins. Can you help us understand what this tool is and how it's incorporated into the Phase II, and how can you possibly leverage it for Phase III?

James Doherty

Yes, absolutely. This is Jim again. I'm happy to take that one. As you say, we have partnered with a company called Unlearn.AI to use these digital twins. And we see it again as another tool, another emerging tool that potentially provides some value. Essentially, these are almost individualized digital models relying on the data from thousands and thousands of patients who have been studied for the progression of their disease in clinical trials and in other formats. And so at this point, there's a tremendous amount of data about how disease progresses over time. And of course, it's incredibly complex and differentiated patient to patient. But what these tools do is allow for using baseline data to predict how their individual course of disease will progress over time.

It's a model, and I think there have to be lots of questions about how robust the models are, what you can say about them, what you can't say about them, but potentially, they have the opportunity to do things like allow you to refine your patient selection. They have the opportunity to do things like be used as a prognostic covariate in analyses following trials. And I think there are a number of potential applications, but honestly, the only way to really evaluate how much value these things have is to begin to get in there and work with it yourself. And so that's effectively what we're doing.

We're using this at this point as an exploratory endpoint. We're trying to understand how these tools might be useful to us in the future. And I think, as I was saying, there are several potential ways they can be used. So that's what our evaluation will be to understand which ones are the best ways to apply this technology for Acumen.

Operator

Our next question comes from Thomas Shrader with BTIG.

Thomas Shrader

A little background or next steps on the EBD franchise. Do you anticipate you would take both candidates into humans? Do you have to start with healthy volunteers? And any sense of how many patients or people you would need to get a read on anemia?

Daniel O'Connell

Thanks, Tom. Jim, why don't you take that one as well?

James Doherty

Yes, happy to. Some great questions, Tom. These are things that the team is actively working on at this point. To the first question, we have identified and nominated two candidates, ACU401 and ACU301. We're doing work on both molecules, and it really is intended to identify which one offers what we think is the best overall profile. So what we would intend to do is move into clinical development with one molecule, and that'll be the one that we think offers the best of possible profiles.

As far as additional work that we're doing, there's a tremendous amount of work on CMC and on tox study preparation in preparation for our plan to file an IND in mid-2027. And, I think we're still working on study design. There's a lot of active discussion around it. We've got a lot of experience from the INTERCEPT-AD study with sabirnetug that is going to help us identify what's exactly the best trial design to use. I think what I could say at this point is it's really going to come down to what's the most efficient design. We are going to try to get as much information as we can as we did in the INTERCEPT-AD study, but we also wanted to move this exciting program forward as quickly as we can. So more details later on what those design choices are going to turn out to be. But I can tell you there's a lot of active discussion right now with the program team trying to land what is going to be the most efficient design.

Thomas Shrader

And are you going to start in healthy volunteers or are you not saying?

James Doherty

So, that's one of the things that we're going to see. I think the goal is to transition to patients as quickly as we think is practical because you get a lot of valuable information from patients, as in INTERCEPT-AD. But I think, exactly when that would be is honestly one of the things that we're still talking about. So, yes, I just, we haven't really made a final decision yet.

Thomas Shrader

And one quick one for Dan. Do you expect to go radio silent at some point? And any guidance about when?

Daniel O'Connell

So, Tom, we continue to be convinced we'll have the topline results for ALTITUDE-AD late '26, consistent with our guiding for some time now. We have mentioned, as I mentioned on the call, we'll have an Investor Relations Day, September 16. And that'll be a forward-looking public-facing discussion. We anticipate participating in some of the early fall activities. So we'll be visible and accessible at some point as we get closer to the end of the year. In the fourth quarter, I think we will probably have to shut down some of our public-facing engagement in anticipation of results. But the timing and specific dates for that, can't comment on.

Operator

Our next question comes from Geoff Meacham with Citi.

Geoffrey Meacham

I have two quick ones. The first, I know the focus on oligomers obviously differentiates you from Kisunla and Leqembi, but how would you set expectations on safety and tolerability and the differences there? I guess, particularly as we get more real-world experience with these two agents in the industry commercially.

Second question, I want to get your view of the recent competitor tau data when you kind of think about the post-ALTITUDE-ADdata. Is there a way to fast track perhaps a combo proof of concept if you think that's a viable strategy?

Daniel O'Connell

Thanks, Geoff. Good questions. I think in terms of safety, tolerability, and sabirnetug, as we described, ALTITUDE-ADwith two active doses is intended to demonstrate a clinical efficacy signal and a risk-benefit profile, both inclusive of the clinical efficacy relative to safety that is differentiated from existing treatments. So we're hopeful and enthusiastic about that possibility. And really just the magnitude of the study, the duration of exposure, we think it's a well-designed study to underpin and validate the oligomer hypothesis as we've positioned it. So that's sort of our expectations for sabirnetug and ALTITUDE.

I think that you mentioned the, I think that you're referring to the Biogen BIIB080 program that was reported at AAIC in July. And I think those are interesting data. It looks as though they'll move into a Phase III study for that molecule. And I think it serves as, depending on how you view it, the first clinical validation of a tau-directed approach. Ultimately, I think we take the view that Alzheimer's is a disease that will be more adequately addressed with combination strategies. So we'll continue to evaluate ways to leverage not only our portfolio of A-beta oligomer-directed approaches or treatments with other potentially synergistic combinations whether it be tau or anti-inflammatory approaches, but it just sort of underpins sort of the stage we're at in terms of establishing better treatment options for patients.

We think the future is quite bright for safer, more efficacious, and more robust treatment for the early stages of the disease. And as I'm sure folks on the call are aware, the move into the preclinical population, and hopefully a way to avert or otherwise delay the onset of symptoms. So it is a really robust innovation ecosystem right now in the space, and we think that will continue to accelerate both commercially with products being adopted and grown in the marketplace and then with further research innovations that will continue to build on better options for patients.

Eric Siemers

Yes, and this is Eric. If I could just expand on that a little bit. In terms of safety and tolerability, there's sort of two aspects of that that are differentiated with sabirnetug. So first of all, it's the target. It's very selective for oligomers rather than plaque, and we think that that has some potential benefits in terms of safety. And the other thing that is important to keep in mind, I think, is that this is an, what's called an IgG2 antibody rather than an IgG1 antibody. Without going into too many details, the IgG -- all the other monoclonal antibodies are IgG1s, and they have more what's called effector function.

In other words, they call in your immune system to get rid of things that you don't want there. In the case of these monoclonals, it's typically plaque. And that can lead to problems like ARIA. But for an IgG2, there's less of this effector function, so it's less effect on calling in immune cells. And for our mechanism, targeting oligomers, you really don't need that to happen anyway. So there's two reasons to think that our safety and tolerability could be quite good. One is that we have this differentiated target, oligomers, and the second is that we have an IgG2 antibody with less effector function and less immune system activation. So we're looking forward to seeing the data from ALTITUDE, obviously.

Operator

Our next question comes from Dev Prasad with Lucid Capital Markets.

Dev Prasad

Just a couple of follow-up questions. First is to follow up on the biomarker data question. Will that biomarker data be in the topline release or will it follow later? And the second is, what should we expect from September 16 IR Day? Will it include new EBD data or a preview of ALTITUDE-ADanalysis plan or a venue to select EBD lead candidates?

Daniel O'Connell

Thanks, Dev. So for your first question, the topline results, as I mentioned in the prepared remarks, will include the primary outcome, the iADRS, which is a composite including both cognitive and functional measures involving the ADAS-Cog as well as the ADCS Activities of Daily Living. We'll also have the CDR Sum of Boxes, again, another cognitive functional endpoint familiar to the agency and others in the field. We intentionally will include both fluid and imaging biomarkers as part of those topline results. We really want the ALTITUDE-ADreadout to be a robust readout that really determines sabirnetug's safety and clinical efficacy as part of the study design. So, yes, we do anticipate having both imaging and fluid biomarkers with the topline results late this year.

Alex Braun

And then for IR Day, yes, so I would expect that to be more of a review of the investment thesis of Acumen. So whoever would like to get up to speed on sabirnetug and our EBD program prior to that Phase II data, that would be a good event for, viewers to tune into. So, yes, please keep it on your calendar.

Operator

I'm showing no further questions at this time. I'd like to turn the call back over to Alex Braun for closing remarks.

Alex Braun

Thanks, Michelle, and thanks to everyone for tuning in today. As always, we are at the company for follow-up questions, and I hope everyone has a wonderful day.

Operator

Thank you for your participation. You may now disconnect.