Acumen (NASDAQ: ABOS) advances two EBD Alzheimer’s drug candidates
Filing Impact
Filing Sentiment
Form Type
8-K
Rhea-AI Filing Summary
Acumen Pharmaceuticals has nominated two Enhanced Brain Delivery (EBD) development candidates, ACU301 and ACU401, for Alzheimer’s disease under its collaboration with JCR Pharmaceuticals and has exercised its option to license and develop them. The candidates combine Acumen’s amyloid-beta oligomer–selective antibodies with JCR’s J-Brain Cargo blood-brain barrier–penetrating technology.
Both candidates showed strongly enhanced brain penetration in non-human primates, with antibody levels 14–40x higher than native antibodies at 24 hours, low anemia risk and no observed adverse events across tested species. They also demonstrated favorable stability and plasma pharmacokinetics after subcutaneous dosing. Acumen is conducting Investigational New Drug–enabling activities to support a planned IND submission in mid-2027 while continuing its Phase 2 ALTITUDE-AD trial of sabirnetug (ACU193) in early Alzheimer’s disease.
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Insights
Acumen advances two preclinical EBD Alzheimer’s candidates with strong brain-penetration data, but they remain early-stage assets.
Acumen has nominated ACU301 and ACU401 as Enhanced Brain Delivery candidates using JCR’s J-Brain Cargo to move antibodies across the blood-brain barrier. This expands its Alzheimer’s portfolio beyond sabirnetug (ACU193), which is already in a Phase 2 ALTITUDE-AD study.
Preclinical data show 14–40x higher brain antibody levels in non-human primates versus native antibodies at 24 hours, favorable subcutaneous pharmacokinetics, low anemia risk and no observed adverse events across tested species. These are encouraging, but preclinical results often do not translate directly into clinical success.
IND-enabling work is underway toward a mid-2027 Investigational New Drug submission for the EBD candidates, while Phase 2 sabirnetug results are expected in late 2026. Future disclosures around IND acceptance and Phase 2 topline data will clarify how these programs shape Acumen’s long-term Alzheimer’s franchise.
8-K Event Classification
3 items: 7.01, 8.01, 9.01
3 items
Item 7.01
Regulation FD Disclosure
Disclosure
Material non-public information disclosed under Regulation Fair Disclosure, often investor presentations or guidance.
Item 8.01
Other Events
Other
Voluntary disclosure of events the company deems important to shareholders but not covered by other items.
Item 9.01
Financial Statements and Exhibits
Exhibits
Financial statements, pro forma financial information, and exhibit attachments filed with this report.
Key Figures
Brain penetration increase: 14–40x higher antibody levels
Planned IND timing: Mid-2027
ALTITUDE-AD enrollment: 542 participants
+2 more
5 metrics
Brain penetration increase
14–40x higher antibody levels
Non-human primate brain levels vs native antibodies at 24 hours
Planned IND timing
Mid-2027
Targeted Investigational New Drug submission for EBD candidates
ALTITUDE-AD enrollment
542 participants
Phase 2 trial in early Alzheimer’s disease
ALTITUDE-AD dosing interval
Once every four weeks
Sabirnetug (ACU193) infusion schedule in Phase 2 trial
Fast Track designation
Granted by U.S. FDA
Sabirnetug (ACU193) for treatment of early Alzheimer’s disease
Key Terms
Enhanced Brain Delivery, J-Brain Cargo, Investigational New Drug (IND), receptor-mediated transcytosis, +2 more
6 terms
Enhanced Brain Delivery medical
"Acumen Pharmaceuticals Announces Nomination of Two Enhanced Brain Delivery™ (EBD™) Development Candidates"
J-Brain Cargo medical
"JCR’s validated transferrin-receptor-targeting blood-brain barrier-penetrating technology, termed J-Brain Cargo®"
Investigational New Drug (IND) regulatory
"IND-enabling activities are ongoing to support IND submission in mid-2027"
An investigational new drug (IND) is a drug or biologic that is being tested but has not yet been approved for general use; it is the application and formal status that allows a company to begin human clinical trials under regulator oversight. Investors care because an IND marks the transition from lab work to human testing — like getting a permit to run real-world experiments — which creates important milestones, costs, timelines and regulatory risk that drive a development-stage company's value.
receptor-mediated transcytosis medical
"delivers drugs to target tissues, including the central nervous system, through receptor-mediated transcytosis"
A natural cell process where a molecule binds to a specific surface receptor and is carried across a cell barrier inside the cell, like a courier picking up a package at one door and delivering it out the other. It matters to investors because companies use this route to deliver medicines or imaging agents into hard-to-reach places (for example, across the blood–brain barrier), which can determine a product’s technical feasibility, market potential, regulatory hurdles, and valuation.
Fast Track designation regulatory
"Sabirnetug has been granted Fast Track designation for the treatment of early AD by the U.S. Food and Drug Administration"
A "fast track designation" is a process that speeds up the review and approval of a product or project, allowing it to reach the market or be completed more quickly than usual. For investors, it can signal that a product may become available sooner, potentially leading to earlier revenue or benefits, and indicating a priority status that might influence company performance and market opportunities.
Phase 2, multi-center, randomized, double-blind, placebo-controlled medical
"ALTITUDE-AD is a Phase 2, multi-center, randomized, double-blind, placebo-controlled clinical trial"
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
FORM 8-K
CURRENT REPORT
Pursuant to Section 13 or 15(d)
of the Securities Exchange Act of 1934
Date of report (Date of earliest event reported): June 12, 2026
(Exact name of Registrant as Specified in Its Charter)
(State or Other Jurisdiction of Incorporation) | (Commission File Number) | (IRS Employer Identification No.) | ||||||
| (Address of Principal Executive Offices) | (Zip Code) | ||||
Registrant’s Telephone Number, Including Area Code: (617 ) 344-4190
(Former Name or Former Address, if Changed Since Last Report)
Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instructions A.2. below):
| Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) | |||||
| Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) | |||||
| Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) | |||||
| Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) | |||||
Securities registered pursuant to Section 12(b) of the Act:
| Title of each class | Trading Symbol(s) | Name of each exchange on which registered | ||||||||||||
Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).
Emerging growth company x
If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. o
Item 7.01 Regulation FD Disclosure
On June 16, 2026, Acumen Pharmaceuticals, Inc. (the “Company”) issued a press release announcing the nomination of two enhanced brain delivery (“EBD”) development candidates for the treatment of Alzheimer’s disease (“AD”) pursuant to its collaboration agreement with JCR Pharmaceuticals Co. Ltd. (“JCR”) and the exercise of the Company’s option pursuant to the collaboration agreement to license and develop such development candidates. A copy of that press release is attached as Exhibit 99.1 to this Current Report on Form 8-K (this “Report”).
The information in this Item 7.01 of this Report (including Exhibit 99.1), is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934 (the “Exchange Act”), as amended, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such filing. The Company’s submission of this Report shall not be deemed an admission as to the materiality of any information required to be disclosed solely to satisfy the requirements of Regulation FD.
Item 8.01 Other Events
On June 16, 2026, the Company announced the nomination of two EBD development candidates for the treatment of AD pursuant to its collaboration agreement with JCR and the exercise of its option pursuant to the collaboration agreement to license and develop such development candidates. Building on preclinical data from both in vitro and in vivo studies, the Company’s exercise of its option will enable it to advance the potential development of both candidates, which combine the Company’s amyloid-beta oligomer (“AβO”)-selective antibody expertise and JCR’s validated transferrin-receptor-targeting blood-brain barrier-penetrating technology, termed J-Brain Cargo. The Company’s research on EBD technology is part of the Company’s ongoing collaboration with JCR, which was previously announced in July 2025.
One of the two EBD development candidates selected by the Company for further development is a bispecific antibody derived from sabirnetug, and the other is based on a novel, next generation AβO-selective antibody with differentiated properties, known as ACU234. As previously disclosed by the Company in March 2026, both of the EBD development candidates demonstrated consistent and predictive results in preclinical studies across multiple models, including murine and non-human primate (“NHP”) studies. The candidates both achieved enhanced brain penetration, with antibody levels 14-40x higher in NHPs than native antibodies at 24 hours. Assessment of a panel of hematology endpoints in NHPs suggested a low risk of anemia, and there were no adverse events observed across all tested species. Additionally, both of the EBD development candidates exhibited favorable stability and plasma PK profiles in NHPs following subcutaneous (“SC”) administration, supporting their potential suitability for SC dosing in patients.
This Report contains forward-looking statements within the meaning of the federal securities laws. Any statements in this Report that are not historical facts may be considered “forward-looking statements,” including statements regarding the Company’s plans with respect to the future development of the EBD development candidates selected pursuant to its collaboration agreement with JCR and the expected clinical and therapeutic potential of the EBD development candidates and JCR’s J-Brain Cargo technology. These forward-looking statements are based on current expectations and are not guarantees of future performance. Further, the forward-looking statements are subject to limitations listed in Exhibit 99.1 and in the other reports of the Company filed with the Securities and Exchange Commission, including that actual events or results may differ materially from those in the forward-looking statements.
Item 9.01 Financial Statements and Exhibits.
(d) Exhibits
| Exhibit No. | Description | |||||||
| 99.1 | Press Release, dated June 16, 2026 | |||||||
| 104 | Cover Page Interactive Data File (the cover page XBRL tags are embedded within the inline XBRL document) | |||||||
SIGNATURES
Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.
| Acumen Pharmaceuticals, Inc. | ||||||||
| Dated: June 16, 2026 | By: | /s/ Derek Meisner | ||||||
Derek Meisner Chief Legal Officer | ||||||||
Exhibit 99.1
Acumen Pharmaceuticals Announces Nomination of Two Enhanced Brain Delivery™ (EBD™) Development Candidates for the Treatment of Alzheimer’s Disease
•ACU301 and ACU401 were nominated in the EBD program as part of the exercise of Acumen’s option under its license agreement with JCR Pharmaceuticals
•EBD technology represents the only anti-amyloid oligomer program combining a validated blood-brain barrier-penetrating technology with a therapeutic antibody tested in the clinic
•Acumen’s EBD candidates are designed to achieve higher brain penetration with potential for improved safety compared to native antibodies and delivered in a stable, low volume subcutaneous administration format
•Investigational New Drug (IND)-enabling activities are ongoing to support IND submission in mid-2027
NEWTON, Mass., Jun. 16, 2026 -- Acumen Pharmaceuticals, Inc. (NASDAQ: ABOS) (Acumen or the Company), a clinical-stage biopharmaceutical company developing novel therapeutics that target soluble amyloid beta oligomers (AβOs) for the treatment of Alzheimer’s disease (AD), today announced the nomination of two development candidates in its Enhanced Brain Delivery (EBD) program as treatments for AD. Building on robust preclinical data from both in vitro and in vivo studies, the Company has exercised its option with JCR Pharmaceuticals (JCR) as part of its previously signed agreement and will advance both candidates combining Acumen’s AβO-selective antibody expertise and JCR’s validated transferrin-receptor-targeting blood-brain barrier-penetrating technology, termed J-Brain Cargo®. By selecting these two candidates, the Company is expanding its optionality by nominating a bispecific antibody derived from sabirnetug as well as one based on a novel, next generation AβO-selective antibody with differentiated properties, known as ACU234.
“The nomination of these candidates marks an important step forward in our effort to bring meaningful new treatment options to patients with Alzheimer’s disease,” said Jim Doherty, President and Chief Development Officer of Acumen. “By leveraging JCR’s J-Brain Cargo® alongside our oligomer-selective antibodies, we’re building a differentiated portfolio of bispecific antibodies designed to overcome the challenges of delivering therapeutics across the blood-brain barrier for the treatment of this devastating disease. We are advancing IND-enabling activities toward a mid-2027 IND submission and are excited about the potential to offer patients and caregivers more effective and convenient therapeutic options.”
As announced in a March 2026 press release, preclinical studies demonstrated consistent and predictive results across multiple models, including murine and non-human primate (NHP) studies. The candidates achieved significantly enhanced brain penetration, with antibody levels 14-40x higher in NHPs than native antibodies at 24 hours. Assessment of a panel of hematology endpoints in NHPs suggested a low risk of anemia, and there were no adverse events observed across all tested species. Additionally, the EBD development candidates exhibited favorable stability and plasma PK profiles in NHPs following subcutaneous (SC) administration, supporting their suitability for SC dosing in patients. Further information will be presented at a future medical meeting.
J-Brain Cargo® technology is JCR’s proprietary drug delivery system that efficiently delivers drugs to target tissues, including the central nervous system, through receptor-mediated transcytosis. It is applicable to various modalities
including antibodies, enzymes, oligonucleotides, lipid nanoparticles, gene and cell therapy, peptides, and decoy receptors. Acumen’s research on EBD technology is part of an ongoing collaboration between Acumen and JCR announced in July 2025.
About Sabirnetug (ACU193)
Sabirnetug (ACU193) is a humanized monoclonal antibody (mAb) discovered and developed based on its selectivity for soluble AβOs, which are a highly toxic and pathogenic form of Aβ, relative to Aβ monomers and amyloid plaques. Soluble AβOs have been observed to be potent neurotoxins that bind to neurons, inhibit synaptic function, and induce neurodegeneration. By selectively targeting toxic soluble AβOs, sabirnetug aims to address the hypothesis that soluble AβOs are an early and persistent underlying cause of the neurodegenerative process in AD. Sabirnetug has been granted Fast Track designation for the treatment of early AD by the U.S. Food and Drug Administration and is currently being evaluated in a Phase 2 study in patients with early AD.
About ALTITUDE-AD (Phase 2)
Initiated in 2024, ALTITUDE-AD is a Phase 2, multi-center, randomized, double-blind, placebo-controlled clinical trial designed to evaluate the efficacy and safety of sabirnetug (ACU193) infusions administered once every four weeks in slowing cognitive and functional decline as compared to placebo in participants with early Alzheimer's disease. The study has enrolled 542 individuals with early Alzheimer’s disease (mild cognitive impairment or mild dementia due to AD) at multiple investigative sites located in the United States, Canada, the European Union and the United Kingdom. Topline results are expected in late 2026. More information can be found on www.clinicaltrials.gov, NCT identifier NCT06335173.
About Acumen Pharmaceuticals, Inc.
Acumen Pharmaceuticals is a clinical-stage biopharmaceutical company developing a novel therapeutic that targets toxic soluble amyloid beta oligomers (AβOs) for the treatment of Alzheimer’s disease (AD). Acumen’s scientific founders pioneered research on AβOs, which a growing body of evidence indicates are early and persistent triggers of Alzheimer’s disease pathology. Acumen is currently focused on advancing its investigational product candidate, sabirnetug (ACU193), a humanized monoclonal antibody that selectively targets toxic soluble AβOs, in its ongoing Phase 2 clinical trial ALTITUDE-AD (NCT06335173) in early symptomatic AD, following positive results in its Phase 1 trial INTERCEPT-AD. Acumen is investigating a subcutaneous formulation of sabirnetug using Halozyme’s proprietary ENHANZE® drug delivery technology. Acumen is also collaborating with JCR Pharmaceuticals to develop an Enhanced Brain Delivery™ (EBD™)-enabled therapy for Alzheimer’s disease utilizing a transferrin-receptor-targeting blood-brain barrier-penetrating technology. The company is headquartered in Newton, Mass. For more information, visit www.acumenpharm.com.
About the J-Brain Cargo® Platform Technology
JCR Pharmaceuticals has developed a proprietary blood-brain barrier (BBB)-penetrating technology, J-Brain Cargo®, to bring biotherapeutics into the central nervous system (CNS). The first drug developed based on this technology is IZCARGOTM (INN: pabinafusp alfa) and is approved in Japan for the treatment of a lysosomal storage disorder.
About JCR Pharmaceuticals Co., Ltd.
JCR Pharmaceuticals Co., Ltd. is a global specialty pharmaceutical company that develops treatments that go beyond rare diseases to solve the world’s most complex healthcare challenges. JCR continues to build upon our 50-year legacy in Japan while expanding our global footprint into the US, Europe, and Latin America. JCR’s innovative therapies address conditions like growth disorder, MPS II, Fabry disease, acute graft-versus-host disease, and renal anemia. JCR is also developing treatments for rare diseases like MPS I, MPS II, MPS IIIA and B, and more. For more information, visit https://jcrpharm.com/.
Forward-Looking Statements
This press release contains forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995. Any statement describing Acumen’s goals, expectations, financial or other projections, intentions or beliefs is a forward-looking statement and should be considered an at-risk statement. Words such as “believes,” “expects,” “anticipates,” “could,” “should,” “would,” “seeks,” “aims,” “plans,” “potential,” “will,” “milestone” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Forward-looking statements include statements concerning Acumen’s business, the therapeutic potential of Acumen’s product candidate, sabirnetug (ACU193) and the potential of two development candidates in Acumen’s Enhanced Brain Delivery (EBD) program. These statements are based upon the current beliefs and expectations of Acumen management, and are subject to certain factors, risks and uncertainties, particularly those inherent in the process of discovering, developing and commercializing safe and effective human therapeutics. Such risks may be amplified by the impacts of geopolitical events and macroeconomic conditions, such as rising inflation and interest rates, supply disruptions and uncertainty of credit and financial markets. These and other risks concerning Acumen’s programs are described in additional detail in Acumen’s filings with the Securities and Exchange Commission (“SEC”), including in Acumen’s most recent Annual Report on Form 10-K, and in subsequent filings with the SEC. Copies of these and other documents are available from Acumen. Additional information will be made available in other filings that Acumen makes from time to time with the SEC. These forward-looking statements speak only as of the date hereof, and Acumen expressly disclaims any obligation to update or revise any forward-looking statement, except as otherwise required by law, whether, as a result of new information, future events or otherwise.
Investors:
Alex Braun
abraun@acumenpharm.com
Alex Braun
abraun@acumenpharm.com
Media:
ICR Healthcare
AcumenPR@icrhealthcare.com
ICR Healthcare
AcumenPR@icrhealthcare.com
FAQ
What did Acumen Pharmaceuticals (ABOS) announce in this Form 8-K?
Acumen announced it nominated two Enhanced Brain Delivery (EBD) development candidates, ACU301 and ACU401, for Alzheimer’s disease. The company exercised its option under a JCR Pharmaceuticals collaboration to license and develop these candidates, which use J-Brain Cargo blood-brain barrier-penetrating technology with Acumen’s oligomer-selective antibodies.
How strong were the preclinical results for Acumen’s new EBD Alzheimer’s candidates?
In preclinical non-human primate studies, the EBD candidates achieved antibody levels 14–40x higher in the brain than native antibodies at 24 hours. Hematology assessments suggested a low risk of anemia, no adverse events were observed across tested species, and subcutaneous dosing produced favorable stability and plasma pharmacokinetic profiles.
When does Acumen (ABOS) expect to file an IND for its EBD candidates?
Acumen reports that Investigational New Drug (IND)-enabling activities are underway to support an IND submission in mid-2027. This planned submission would cover the two Enhanced Brain Delivery development candidates, ACU301 and ACU401, being advanced under the company’s collaboration with JCR Pharmaceuticals.
How do the EBD candidates fit with Acumen’s existing sabirnetug (ACU193) program?
One EBD candidate is a bispecific antibody derived from sabirnetug, while the other is based on a novel next-generation AβO-selective antibody, ACU234. Sabirnetug itself is in the Phase 2 ALTITUDE-AD trial for early Alzheimer’s disease and has U.S. FDA Fast Track designation for this indication.
What is JCR’s J-Brain Cargo technology used in Acumen’s EBD program?
J-Brain Cargo is JCR Pharmaceuticals’ proprietary blood-brain barrier-penetrating platform that delivers therapies into the central nervous system via receptor-mediated transcytosis. It can be applied to antibodies, enzymes, oligonucleotides, lipid nanoparticles, gene and cell therapies, peptides, and decoy receptors according to the disclosure.
What is the status of Acumen’s Phase 2 ALTITUDE-AD trial mentioned in the filing?
ALTITUDE-AD is a Phase 2, multi-center, randomized, double-blind, placebo-controlled trial of sabirnetug (ACU193) in early Alzheimer’s disease. It has enrolled 542 participants who receive infusions every four weeks, and topline results are expected in late 2026 based on the company’s description.