Alector, Inc. Securities Lawsuit Investigation

Shamis & Gentile P.A., a law firm that advocates for investors who are victims of securities fraud, is investigating potential claims against Alector, Inc. (ALEC)

If you purchased or acquired Alector securities between October 2023 and October 2025, you may be eligible to join this securities investigation and seek compensation.

About Alector

Alector is a biotechnology company headquartered in South San Francisco, California. The company develops immuno-neurology therapies for neurodegenerative diseases such as frontotemporal dementia and Alzheimer’s disease.

Its lead drug candidate, latozinemab (AL001), targeted frontotemporal dementia caused by a progranulin gene mutation and had received Orphan Drug, Breakthrough Therapy, and Fast Track designations from the U.S. Food and Drug Administration.

Potential Concerns Under Investigation

Attorneys are examining whether Alector may have made materially incomplete or misleading statements about the progress, expectations, and regulatory interactions related to its pivotal INFRONT-3 Phase 3 clinical trial evaluating latozinemab for frontotemporal dementia caused by a GRN mutation.

Throughout 2024 and 2025, Alector reported that the INFRONT-3 trial remained on track and that topline data were expected by the fourth quarter of 2025. In its February 2025 earnings release and subsequent quarterly updates in May and August 2025, company leadership reiterated confidence in the trial’s timeline and scientific approach.

Investigators are reviewing whether Alector’s communications adequately disclosed the trial’s risks and limitations, including the scientific uncertainty around whether elevating progranulin would translate into measurable clinical benefit. The company stated it had aligned with the U.S. Food and Drug Administration and the European Medicines Agency on conducting the primary analysis for symptomatic participants in INFRONT-3, supporting an enrollment target of about 90 to 100 individuals.

Attorneys may review whether that framing accurately reflected the nature of the agency’s guidance and potential regulatory challenges.

On October 21, 2025, Alector announced that latozinemab did not meet the trial’s co-primary clinical endpoint and showed no effect on disease progression. The company stated it would discontinue the INFRONT-3 open-label extension and follow-on studies, implement a 49% workforce reduction, and that its president and head of research and development would step down.

Following the disclosure, Alector’s stock declined nearly 50%, falling from $3.21 per share on October 21 to $1.61 per share by market close on October 22, 2025, causing investors significant harm.

Legal professionals are reviewing whether investor communications during the class period accurately represented the risks, regulatory context, and potential outcomes of the latozinemab program, as well as whether the October 2025 results revealed information that had not been clearly conveyed to shareholders.

Your Rights and Next Steps

Investors who purchased or held Alector securities during the relevant period may have important legal options.

Potential next steps:

• Review whether your investment falls within the October 27, 2023 to October 21, 2025 period.
• Gather any account statements or trade confirmations showing your purchases or sales.
• Submit your information to learn if you may qualify for potential recovery.
• There is no cost or obligation to participate in the investigation.

You May Be Entitled to Compensation

If you purchased Alector securities and suffered losses, you may be eligible to join this investigation and seek compensation for your losses. Securities investigations often move quickly, so time is of the essence.

To learn more and determine if you qualify, complete the form below to join the investigation.