Acumen Pharmaceuticals, Inc.

Hello, and thank you for standing by. Welcome to Acumen Pharmaceuticals Q2 2024 conference call and webcast. At this time, all participants are in a listen-only mode. After the speaker's presentation, there will be a question and answer session. To ask the question during this session, you will need to press star 11 on your telephone. You will then hear an automated message advising your hand is raised. To withdraw your question, please press star 11 again. I would now like to turn the call over to Alex Braun, Head of Investor Relations. Please go ahead.

Thank you, Operator. Good morning and welcome to the Acumen Conference call to discuss our business update and financial results for the quarter ended June 30th, 2024. With me today are Dan O'Connell, our CEO, and Matt Zuga, our CFO and Chief Business Officer. Dan and Matt have some 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. These statements are subject to risks and uncertainties that could cause actual results to differ materially from those described in the forward-looking statements. Please see slide two 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.

Thanks, Alex. Good morning, everyone, and thanks for joining us today. We've made significant progress in the first half of 2024 as we continue to execute our clinical plans for Subirnatug, our next-generation amyloid beta-ligamer-targeted antibody for the treatment of early Alzheimer's disease. AltitudeAD, our Phase II study designed to evaluate the clinical efficacy and safety of Subirnatug in patients with MCI or mild dementia due to AD, is actively enrolling. ALTITUDE-AD is a randomized, double-blind, placebo-controlled, three-arm study with approximately 180 participants per treatment arm for a total of 540 participants. ALTITUDE currently has more than 50 sites active across North America, the UK, and the EU, with the first subject dosed in May 2024. At present, enrollment in ALTITUDE is progressing faster than our original projections, which is highly encouraging. We attribute this to Sobernatug's distinct profile based on its mechanism of action and positive feedback and interest from investigators supported by our strong phase one data. Additionally, our team has built highly productive working relationships with quality trial sites in all three regions. These combined factors have translated into an encouraging enrollment rate and underpin the growing interest in novel treatment options for early AD and differentiated treatment potential of Sobernatug. In July, we also announced we had dosed our first subject in a phase one study of subcutaneous Subirnatug. The study will compare the pharmacokinetics between intravenous and subcutaneous administrations of Subirnatug in healthy volunteers. We view this work stream as an important extension of Subirnatug's product profile, which aims to offer flexibility and convenience in dosing for patients and caregivers. We anticipate the top-line results from this study will be available in the first quarter of 2025. Once we have the PK bioavailability results in hand, we will be best positioned to discuss next steps and clinical plans for subcutaneous suburnatide. Turning now to continued learnings from our clinical experience with suburnatide, the Acumen team recently presented further data analysis from the Intercept-AD trial at the Alzheimer's Association International Conference, or AAIC. Our team presented posters at this major Alzheimer's medical conference, detailing patient interviews, biomarker data supportive of Suburnatug's mechanism of action, and Acumen's ultra-sensitive method of measuring small amounts of Suburnatug in cerebral spinal fluid. The takeaways from our patient interviews underscore the importance of incorporating the patient voice into trial design and humanizing the unmet need in Alzheimer's disease. As expected, nearly all patients reported difficulty with memory and cognition, difficulty with getting lost, difficulty with communication, and changes in mood were also commonly reported. Almost 90% of patients would like a treatment to slow the progression of disease or keep it from getting worse, as well as maintain the ability to recognize loved ones. We also received strong interest in the synaptic biomarker changes observed in our phase one study. Both pre- and post-synaptic cerebrospinal fluid proteins, VAMP2 and neurogranin, showed significant reduction towards normalization, which is consistent with Sobernafug's ability to inhibit amyloid beta-oligomer synaptic binding. These posters can be found on the investor section of our website if you haven't already had a chance to review them. As usual, there was a great deal of interesting information shared at AEIC, including a number of topics relevant to our subvertotype program. These topics included the continued development of fluid biomarkers like pTau217 as diagnostics for tracking the progression of Alzheimer's, further data on the important role that soluble amyloid data species play in the pathophysiology of AD, and extended safety and efficacy data on chronic dosing with anti-amyloid monoclonal antibody therapies. We believe the increased acceptance of the toxicity and persistence of soluble amyloid beta species, such as oligomers, will help move the field towards next-generation antibodies, such as the Bernadote, and the confluence of fluid biomarker breakthroughs will support expanded future access to novel treatments in AD. Finally, we are planning to host a virtual R&D day on October 2nd. We intend for this event to provide a deep dive into the scientific rationale supporting Sobernatug's mechanism of action, our phase one clinical results, and phase two clinical plans for Sobernatug. We will communicate the registration details and agenda closer to the event. We remain committed to delivering on our strategic priority to efficiently and thoughtfully advance the clinical development of Sobernatug and are encouraged by the direction the Alzheimer's field is headed with new data and an updated understanding of the disease that is in line with our science. I look forward to updating you as we work towards phase two data that we believe will provide a significant value inflection for the program and demonstrate Subirnatug's true potential as a next gen treatment with a highly compelling benefit to risk profile. And with that, I'll turn the call over to Matt for the financials.

Thank you. Thanks, Dan. As a reminder, our second quarter 2024 financial results are available in the press release we issued this morning and in our 10Q we will file later today. As of June 30th, we had approximately $281 million in cash and marketable securities on our balance sheet and continue to expect the cash runway to last into the first half of 2027. R&D expenses were $19.5 million in the second quarter. The increase over the prior year was primarily due to the increased spending to support the altitude AD trial. GNA expenses were $4.8 million in the quarter, with the increase over the prior year primarily the result of increased headcount. This led to a loss from operations of $24.4 million in the quarter. I'm very pleased with our clinical execution thus far in 2024. We are well resourced for our phase two study and to develop a subcutaneous formulation of Subirnatog and are committed to delivering on the opportunity ahead of us for the benefit of patients, caregivers, and shareholders. And with that, we can open the call for Q&A. Operator?

Thank you.

Ladies and gentlemen, to ask the question, please press star 11 on your telephone and then wait to hear your name announced. To withdraw your question, Please press star one again. Please stand by while we compile the Q&A roster. Our first question comes from the line of Tom Schrader with BTIG. Your line is open.

Good morning. Thanks for taking the question and the updates. I have a question on the phase two trial and what patients you're getting. What is enrollment like in the U.S. with two approved products? Is it tricky or are patients highly compelled by the potential for less ARIA? And I would expect enrollment in Europe, people are very enthusiastic, but are you going to limit or are you going to require some number of U.S. patients? Thank you.

Hi, Tom. Yeah, thanks. Great question. And as I mentioned earlier in the prepared remarks, we are encouraged that the enrollment rate And to date, it has exceeded our expectations from our original forecasts. I think this is a consequence of the unmet need in this population, as well as the phase one data that really underpin the differentiation of Subirnatog. Lastly, the study design itself, the feedback from sites and investigators has been very favorable in that the study incorporates two active doses versus placebo, and then an open label extension. So in terms of choice and participation we're seeing a lot of demand to participate in the altitude ad study and we do anticipate a split between north america and europe um can't haven't preset those those mix but think we'll have patients covering each of the territories or regions that i mentioned earlier okay all right thank you maybe i just add a little bit to that um yeah the the uh

rate at which we're seeing patients really exceeds our projections and expectations, which is great. You might ask yourself why that might be. And as Dan mentioned, it's probably multifactorial, but I think partly it's the strength of our phase one data that was done in patients. We've seen a lot of biomarker changes that are really encouraging for the drug. And secondly, what we've heard from the sites is that They do like the protocol design. It's a phase two study, but really it's like a small phase three study with an open-label extension and the sites like that. We started the study in the U.S., and that's where currently we have most of our patients. But now we're adding sites. We've already added sites in Canada, the U.K., and then Europe. So we'll be enrolling more patients in those other sites. Okay, great.

Thank you.

Thank you. Please stand by for our next question. Our next question comes from the line of Jason Zemestat with Bank of America. Your line is open.

Hi. Good morning. This is Cameron Bosdog on for Jason. Congrats on the quarter and thanks for taking our question. So in thinking about the anti-A-beta commercial landscape, you know, what do you think have been the major challenges or gating factors? Is it educating physicians, you know, engaging with patients, or has it been an issue of infrastructure, payer access, reimbursement? And then, appreciating it's early, but do you see opportunities for Subirnatag to potentially differentiate itself, or is it more that, you know, the broader market needs to finish undergoing maturation itself? Thank you.

Thanks, Cameron. And I think you've listed out the multifactorial sort of issues that are basically inhibiting or at least metering out the ramp and the growth and expansion of these treatments, these first couple of approved products. We think that it's interesting now with Lilly coming into the marketplace, the infrastructure will continue to be built out, that awareness around the possibility of seeking treatment will continue to draw more awareness and patients into this new treatment paradigm. There are also, I think, one of the points we made from the AIC meeting is that the anticipation of fluid biomarkers, you know, blood-based diagnostics, is likely to impact the growth and expansion of this field. So it is multifactorial. I think there's been good progress made, and there will continue to be the infrastructure rolled out. In terms of Sobernatug and differentiation, we absolutely have high conviction that its mechanism is differentiated, and yet as a consequence of that has the promise of differentiating either or both on efficacy and safety. And that's really our single focus is to offer early AD patients an improved treatment option in terms of benefit to risk profile. So I think that addresses most of your questions. I don't know, Jim or Eric, if you have any follow-on comments.

Thank you. Thanks. Please stand by for our next question.

Our next question comes from the line of Paul Matias with Stifel. Your line is open.

Hey, this is Mark. I'm from Paul. Thanks for taking our questions. So, we were curious, what does the path forward look like for the sub-Q formulation for Subirnatug and then You know, would that be assessed in parallel to the intravenous formulation if the phase one were successful? And then separately on that, you know, what dose could you pursue? And would that, you know, enable robust plaque target engagement? Or would that be more of like an oligomer dose? And then if you could provide any additional details for the altitude AD interim analysis, that would be great as well. Thank you.

Sure. I want to direct that one to Jim as our lead on development efforts.

Sure. Happy to take it, Dan. Mark, the answer to your question, I think, is we're the first step, really, for the subcutaneous development program is to understand the bioavailability of a sub-Q version. So, that's the goal of the first study here in Healthy Volunteers is to really align the PK from the sub-Q administration with the halazine formulation with what we're learning from the IV studies from Intercept and ongoing work with Altitude AD. You know, I think beyond that, we have a number of options on how to proceed. I think from the point of view of dosing, the targeting of the dosing is intended to hit the same range that we're targeting with the IV formulation. And the purpose of that, of course, is based on our target engagement data from phase one. We've got high confidence that we are targeting a range that's having an effect dose-dependently on soluble oligomer in the brain. And also, as we've demonstrated from Intercept, some evidence for plaque reduction as well. And I think, you know, we see these as both effects of subvernance. We're focused around the hypothesis. that reduction of soluble oligomers is going to be beneficial to synaptic function and to overall cognitive function in AD. And I think no reason to think that would be different for the subcutaneous formulation. So that's sort of where we stand at this point. Our efforts are to complete the ongoing phase one sub-Q study by the end of the year. And then we'll, based on a data-driven analysis, move forward with next steps.

Thank you. Thank you.

Thank you. Please stand by for our next question.

Our next question comes from the line of Pete Stavropoulos with Cantor Fitzgerald. Your line is open.

Hi, this is Samantha on the line for Pete. Thanks for taking our question. So the Altitude AD study is enrolling patients with early AD Considering the outcomes from other A-beta antibodies in the subpopulations that showed greater clinical benefits, such as those with low tau versus high tau, how are you thinking about the patient population you would like to ideally enroll? Are you looking to have patients with a higher proportion with specific baseline characteristics like centraloid levels, PLAS, or tau to perhaps increase the likelihood of seeing efficacy signals? Thanks so much.

Thanks, Samantha. Eric, do you want to take that one?

Yeah, sure. So, yeah, great question. We're targeting actually the same patient population that we used for the phase one study, which is patients with MCI and mild dementia, which is frequently being called early symptomatic Alzheimer's disease now. You know, as you point out, people who have less tau based on other antibodies may have a better response those results carefully. What we've done in our trial is that people can enter the trial based on either a PET scan, an amyloid PET scan, or CSF. For the PET scans in particular, we're using a visual read, which is what's used in practice right now. But by doing that, you tend to get people with a people who are relatively a little bit earlier in the disease. And so we feel pretty confident that we've targeted the right population here. So there are obviously people who have amyloid and they have Alzheimer's disease, but they're relatively early in the course of it, both based on symptoms and based on PET scans or CSF.

And maybe just to add to that a little bit, Samantha, this is Jim. I think part of the reason we're investing so much in both imaging and fluid-based biomarkers in the altitude study is that the space is still evolving and understanding exactly what the diversity is amongst patient populations. And so I think, as Eric's pointing out, we're very intentionally targeting the early Alzheimer's space. But I think as our understanding as a field grows in this area, Acumen is going to be very well positioned to understand the importance of individual biomarkers and how that's going to relate to the emerging understanding around different patient populations. So, we think we're in pretty good shape at this point.

Thanks so much.

Thank you. Please stand by for our next question. Our next question comes from the line of Trung with UBS. Your line is open.

Hi, guys. Trung Nguyen from UBS. Thanks for taking my questions. Just on the sub-Q administration, I've got a couple on there. So do you have any details on this? Is it an auto-injecture? Can it be done at home or in the hospital? And what's the injection volume that you're using? Just trying to get an idea of the convenience of this product. And then can you just give us any color on what could be presented in OneQ with this data? In particular, could we see any safety data? Thanks very much.

Thanks for the question. I'll just quickly, we will have safety data and we'll have bioavailability data. At this point, we're not guiding or disclosing sort of volumes and so forth. I do think that we're trying to establish the bioequivalence of sub-Q versus IV dosing in that therapeutic range that we're using in altitude AD. And I think we will have looked for a variety of different delivery formats. We have a fairly clear view as to what we want to deliver on in terms of dosing frequency and volumes. But at this point, I'm not prepared to comment. We're fortunate to be partnered up with Halazime on this program, and they've brought to bear a good bit of information and content and been good partners to help us assess how to advance the subcutaneous formulation of sabernetide.

Yeah, and maybe just to expand on that a little bit, just to remind you that this study is in healthy volunteers. It's not in patients. And so ARIA really shouldn't be an issue in terms of safety. So the safety is more just injection site reactions and that sort of thing. But we anticipate that that should be quite good.

And just following up, you mentioned a partnership with Halazime there. Should we expect what the financials there, should we expect to pay our way here? I know it's a bit down the line.

Yeah, so it's down the line. I mean, the terms are not disclosed publicly. I think it's been a matter of public record, though. It's a non-exclusive arrangement with Halazime.

Thanks very much.

Thank you. As a reminder, ladies and gentlemen, that's star 11 to ask the question. Please stand by for our next question. Our next question comes from the line of Ananda Ghosh with AC Wainwright. Your line is open.

Yeah, hi. Congrats on the quarter. I have two questions. The first one is, can P tau 217 predict a low and high tau patient population? are there data from the prior clinical trials? And the second question is, with the licanumab data at the AIC showing a long-term benefit due to its specificity for neutralizing protofibrils, what's the read-through for ECU193?

Thanks, Fernando. Eric, do you want to address that question?

Yeah, so as far as the PTAL217, great question. You know, intuitively, you would sort of think that, well, this is a form of P tau, so it should correlate with tau PET. As it turns out, it's such a sensitive early marker, it actually tends to correlate with amyloid PET, which is not as sensitive. So what we've actually done in our trials is to use PTAL 217 as a screening measure for people who go on then to PET or CSF. And what we found is by doing that, we reduced the number of negative PET scans and negative CSF by about 50%. So it seems to be working quite well as a screening procedure. And we actually think that that's something that could play out in clinical practice, that if physician gets a blood PTAL 217 and a lot of people who otherwise would go on to have a negative PET scan. So I think it's a really good biomarker. And I'm sorry, I didn't quite catch your second question.

You know, with the Likanimab long-term study, they are showing that, you know, that patients have this continued benefit based on the, you know, their ability to target protofibrils. So what's the read-through, you know, with the Subanitab?

Well, yeah, so we've followed that very carefully, and there's really interesting data, and I think What the field is learning, and we're learning along with the field, is that if you just look at amyloid based on PET scans, it's a very slow increase once you've reduced the amyloid that's there. But what you also see is that apparently PET scans are not that sensitive because some of the other pathology increases in GFAP increases in various forms of P tau, those things come back a lot sooner than your PET scan gets worse. And so in our view, that's a good indication that partly because, or maybe because licanumab targets these protofibrils, that when you stop treatment with it, the pathology comes back relatively quickly and And you don't pick that up just based on an amyloid PET scan. And we think that's completely consistent with our hypothesis of targeting these soluble oligomers. Got it. Thanks, Eric. Very helpful.

Thank you. Ladies and gentlemen, I'm showing no further questions in the queue. I would now like to turn the call back to Alex for closing remarks.

Great. Thanks everyone for joining the call today and for your interest in the company. Please don't hesitate to reach out to us if you have any follow-up questions and have a great day.

Ladies and gentlemen, that concludes today's conference call. Thank you for your participation. You may now disconnect.