Acumen Pharmaceuticals, Inc.

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SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This Annual Report on Form 10-K contains forward-looking statements, within the meaning of the Private Securities Litigation Reform Act of 1995, about us and our industry that involve substantial risks and uncertainties. All statements other than statements of historical facts contained in this Annual Report on Form 10-K including statements regarding our future results of operations or financial condition, business strategy and plans and objectives of management for future operations, are forward-looking statements. In some cases, you can identify forward-looking statements because they contain words such as “anticipate,” “believe,” “contemplate,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “plan,” “potential,” “predict,” “project,” “should,” “target,” “will” or “would” or the negative of these words or other similar terms or expressions. These forward-looking statements include, but are not limited to, statements concerning the following:

•the sufficiency of our existing cash and cash equivalents and marketable securities to fund our future operating expenses and capital expenditure requirements;

•our ability to obtain funding for our operations, including funding necessary to develop and commercialize sabirnetug, subject to obtaining necessary regulatory approvals;

•the ability of our clinical trials to demonstrate the safety and efficacy of sabirnetug, and other positive results;

•the therapeutic potential of sabirnetug, including its potential for improved safety and efficacy as compared to other monoclonal antibodies approved and or in development, as well as our expectations concerning our ongoing ALTITUDE-AD clinical trial and any future clinical trials we may conduct;

•the structure, focus, success, cost and timing of our development activities, nonclinical studies and clinical trials, and the reporting of data from those clinical trials;

•our plans relating to commercializing sabirnetug, subject to obtaining necessary regulatory approvals;

•our ability to attract and retain key scientific and clinical personnel;

•our ability to contract with third-party suppliers and manufacturers and their ability to perform adequately;

•our reliance on third parties to conduct clinical trials of sabirnetug and manufacture sabirnetug for nonclinical studies and clinical trials;

•the success of competing therapies that are or may become available;

•our plans and ability to obtain or protect our intellectual property rights, including extensions of existing patent terms where available or the use of data market exclusivity to provide protection from generic or biosimilar versions of our product;

•the scope of protection we are able to establish and maintain for intellectual property rights covering sabirnetug and our technology;

•potential claims relating to our intellectual property;

•existing regulations and regulatory developments in the United States and other jurisdictions;

•our ability to obtain and maintain regulatory approval of sabirnetug, and any related restrictions, limitations and/or warnings in the label of any approved product candidate;

•our plans relating to the further development and manufacturing of sabirnetug, including additional therapeutic indications we may pursue;

•our ability to develop and maintain our corporate infrastructure, including our ability to design and maintain an effective system of internal controls;

•our financial performance; and

•our expectations regarding the time period during which we will be an emerging growth company under the Jumpstart Our Business Startups Act of 2012, or the JOBS Act.

You should not rely on forward-looking statements as predictions of future events. The outcome of the events described in these forward-looking statements is subject to risks, uncertainties and other factors described under the header “Risk Factors” and elsewhere in this Annual Report on Form 10-K. Moreover, we operate in a very competitive and rapidly changing environment. New risks and uncertainties emerge from time to time, and it is not possible for us to predict all risks and uncertainties that could have an impact on the forward-looking statements contained herein. The results, events

ii and circumstances reflected in the forward-looking statements may not be achieved or occur, and actual results, events or circumstances could differ materially from those described in the forward-looking statements.

The forward-looking statements made in this Annual Report on Form 10-K relate only to events as of the date on which the statements are made, and we undertake no obligation to update them to reflect events or circumstances after the date of this Annual Report on Form 10-K or to reflect new information or the occurrence of unanticipated events, except as required by law.

Unless the context otherwise indicates, references in this report to the terms “Acumen,” “the Company,” “we,” “our” and “us” refer to Acumen Pharmaceuticals, Inc.

We may announce material business and financial information to our investors using our investor relations website (investors.acumenpharm.com). We therefore encourage investors and others interested in Acumen to review the information that we make available on our website, in addition to following our filings with the Securities and Exchange Commission, or SEC, webcasts, press releases and conference calls. Our website and information included in or linked to our website are not part of this Annual Report on Form 10-K.

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RISK FACTORS SUMMARY

Our business is subject to a number of risks of which you should be aware before making a decision to invest in our common stock. These risks are more fully described in “Part I, Item 1A. Risk Factors” of this Annual Report on Form 10-K, including the following:

•We are a clinical-stage biopharmaceutical company with a limited operating history.

•We have no product candidates approved for commercial sale, we have never generated any revenue from product sales and we may never be profitable.

•We will require substantial additional funding to finance our operations, complete the development and commercialization of sabirnetug for Alzheimer’s disease, or AD, and evaluate future product candidates. If we are unable to raise this funding when needed, we may be forced to delay, reduce or eliminate our drug development programs or other operations.

•We are substantially dependent on the success of sabirnetug, our sole product candidate, which will require significant clinical testing before we can seek regulatory approval and potentially launch commercial sales, and which may not be successful in clinical trials, receive regulatory approval or be successfully commercialized, even if approved.

•We have concentrated our research and development efforts on the treatment of AD, a field that has to date seen very limited success in drug development.

•Our approach to the potential treatment of AD is based on a novel therapeutic approach, which exposes us to unforeseen risks.

•Nonclinical and clinical drug development involves a lengthy, expensive and uncertain process. The results of nonclinical studies and early clinical trials are not always predictive of future results. Sabirnetug or any other product candidate that we advance into clinical trials may not achieve favorable results in later clinical trials, if any, or receive marketing approval.

•Clinical failure can occur at any stage of clinical development, and we have never submitted a biologics license application or other marketing authorization application.

•We may incur additional costs or experience delays in completing, or ultimately be unable to complete, the development and commercialization of our product candidates.

•If we are unable to enter into a commercial collaboration or, alternatively, establish internal sales, marketing and distribution capabilities for sabirnetug or any other product candidate that may receive regulatory approval, we may not be successful in commercializing those product candidates if and when they are approved.

•We face significant competition in an environment of rapid technological and scientific change, and there is a possibility that our competitors may achieve regulatory approval before us or develop therapies that are safer or more effective than ours.

•We currently rely on contract manufacturing organizations, or CMOs, to supply components of and manufacture sabirnetug. The loss of any of these CMOs or the failure of any of them to meet their obligations to us could affect our ability to develop sabirnetug in a timely manner.

•We intend to rely on contract research organizations and other third parties to conduct, supervise and monitor a significant portion of our research and nonclinical testing and clinical trials for sabirnetug and any future product candidates, and if those third parties do not successfully carry out their contractual duties, comply with regulatory requirements or otherwise perform satisfactorily, we may not be able to obtain regulatory approval or commercialize our product candidates, or such approval or commercialization may be delayed, and our business may be substantially harmed.

•If we are unable to obtain and maintain sufficient intellectual property protection for sabirnetug and any future product candidate, and other proprietary technologies we develop, or if the scope of the intellectual property protection obtained is not sufficiently broad, our competitors could develop and commercialize products similar or identical to ours, and our ability to successfully commercialize our product candidate, and other proprietary technologies if approved, may be adversely affected.

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