Insider Trading January 28, 2026

Acumen Pharmaceuticals CLO Sells Shares After Exercising Options; Company Progresses with Alzheimer’s Trials

Chief legal officer executed option exercise and subsequent sale; Acumen reports Q3 2025 loss while advancing Sabirnetug studies

By Derek Hwang ABOS
Acumen Pharmaceuticals CLO Sells Shares After Exercising Options; Company Progresses with Alzheimer’s Trials
ABOS

Acumen Pharmaceuticals' Chief Legal Officer and Corporate Secretary, Derek M. Meisner, exercised options and then sold the resulting shares under a pre-set 10b5-1 plan on January 26 and January 28, 2026. The transactions involved 17,756 shares and generated proceeds of $53,279. Separately, Acumen reported a net loss for Q3 2025 and continued clinical activity around its lead Alzheimer’s candidate, Sabirnetug, including dosing in an open-label extension and completion of ALTITUDE-AD enrollment.

Key Points

  • Insider activity: Derek M. Meisner exercised options for 17,756 Acumen shares at $1.85 per share and sold those shares under a 10b5-1 plan for aggregate proceeds of $53,279.
  • Clinical progress: Acumen has begun dosing in the open-label extension of its Phase 2 ALTITUDE-AD trial and completed enrollment with 542 participants, and presented collaborative delivery research with JCR Pharmaceuticals.
  • Financials and coverage: The company posted a $26.5 million net loss for Q3 2025, while Stifel maintains a Buy rating and a $10 price target after engaging with company executives.

Transactions by insider

Derek M. Meisner, who serves as Chief Legal Officer and Corporate Secretary of Acumen Pharmaceuticals (NASDAQ:ABOS), carried out an option exercise and related sales on January 26 and January 28, 2026. Meisner exercised options to acquire 17,756 shares of common stock at an exercise price of $1.85 per share, representing a total cost of $32,848.

Under a pre-arranged 10b5-1 trading plan, Meisner sold the 17,756 shares on the same dates. The sales were executed at prices ranging from $3.0005 to $3.0016 per share, producing aggregate proceeds of $53,279.

After completing the option exercise and the sales, Meisner holds 173,999 shares of Acumen Pharmaceuticals directly.


Company financials and development updates

Acumen Pharmaceuticals reported a net loss of $26.5 million for the third quarter of 2025. Despite the reported loss, the company has continued to advance its Alzheimer’s treatment program. The firm has begun dosing participants in the open-label extension of its Phase 2 ALTITUDE-AD clinical trial, providing enrolled subjects with an additional 52 weeks of treatment.

Acumen also disclosed that it presented new research at the 18th Annual Clinical Trials on Alzheimer’s Disease conference. That work, conducted in collaboration with JCR Pharmaceuticals, focused on improved delivery methods designed to enhance antibody delivery to the central nervous system for its Alzheimer’s treatment candidates.

Additionally, Acumen announced completion of enrollment in the ALTITUDE-AD study, which reached a total of 542 participants across multiple regions.


Analyst stance

Stifel continues to rate Acumen Pharmaceuticals as Buy and maintains a $10 price target, following conversations with company executives regarding the lead candidate Sabirnetug and the broader development pipeline.


Context and implications

The insider option exercise followed by an immediate sale under a 10b5-1 plan represents a routine liquidity and tax-management approach often used by corporate officers. Separately, the company’s reported Q3 2025 loss and its continued clinical work on Sabirnetug underscore the dual pressures of funding clinical development while advancing trial programs.

Risks

  • Acumen reported a net loss of $26.5 million for Q3 2025, indicating ongoing funding needs for its clinical programs - this impacts the biotech and capital markets sectors.
  • Advancement of Sabirnetug relies on continued clinical trial progress and data readouts; any delays or adverse results could affect the company’s development trajectory and market perception.
  • Insider sales, even when executed under a pre-arranged 10b5-1 plan, may draw investor attention to executive liquidity events and could influence trading dynamics in the stock.

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