ALEC

EX-99.1

2 alec-ex99_1.htm

EX-99.1

EX-99.1

Exhibit 99.1

Alector Reports Second Quarter 2026 Financial Results and Provides Business Update

Advancing the Alector Brain Carrier (ABC) blood-brain barrier platform across antibodies, enzymes, and siRNA, with AL137 advancing as Alector’s lead ABC-enabled anti-amyloid beta (Aβ) antibody program for Alzheimer’s disease (AD).

Continued progress across AL064/AL164 (ABC-enabled Tau siRNA for AD and other tauopathies) and AL050 (ABC-enabled GCase Enzyme Replacement Therapy for Parkinson’s disease (PD)).

$172.8 million in cash, cash equivalents and investments provide runway at least through 2027

SOUTH SAN FRANCISCO, Calif., August 6, 2026 (GLOBE NEWSWIRE) – Alector, Inc. (Nasdaq: ALEC), a biotechnology company focused on developing therapies to counteract the devastating progression of neurodegeneration, today reported second quarter 2026 financial results and recent portfolio and business updates. As of June 30, 2026, Alector’s cash, cash equivalents, and investments totaled $172.8 million.

"We continue to make steady progress across our ABC-enabled preclinical and research pipeline,” said Arnon Rosenthal, Ph.D., Chief Executive Officer of Alector. “Our work across antibodies, enzymes, and siRNA reflects the versatility of the ABC platform and our strategy to apply it to programs where enhanced brain delivery may address important limitations in the treatment of neurodegenerative diseases. We remain focused on disciplined execution as we advance our portfolio toward clinical development, with the goal of addressing important unmet needs for patients living with neurodegenerative diseases.”

Recent Program Updates

Alector Brain Carrier (ABC): Preclinical and Research Pipeline

Alector’s proprietary Alector Brain Carrier (ABC) blood-brain barrier platform is central to the company’s strategy to enhance therapeutic delivery to the brain. ABC is designed to achieve efficient, enhanced brain delivery through differentiated binding to a distinct region of the transferrin receptor (TfR) and to enable peripheral dosing, while preserving a favorable safety profile. It is adaptable across multiple drug modalities, including antibodies, enzymes, and siRNA.

Core to the platform's design are the principles of versatility, translatability, and differentiated binding. Preclinical studies across multiple ABC-enabled programs have

shown robust brain penetration, supporting the advancement of a broad pipeline directed at the underlying drivers of neurodegenerative diseases.

AL137

• Following successful completion of IND-enabling studies evaluating both subcutaneous (SC) and intravenous (IV) administration, Alector selected AL137 as the lead molecule for its anti-amyloid beta (Aβ) antibody program for AD, with AL037 retained as a backup candidate. The company is targeting an IND submission in Q1 2027 and first-in-human dosing in Australia no later than April 2027.

• AL137 combines Alector’s proprietary high-affinity fully human anti-Aβ antibody which selectively binds pyroglutamate-3 (PyroGlu3-Aβ), a validated and pathogenic form of Aβ enriched in amyloid plaques, with the company’s proprietary ABC platform. Based on preclinical studies, AL137 is designed to be delivered SC and to combine several differentiated attributes intended to optimize efficacy, safety, convenience, and manufacturability, including:

• High brain exposure and efficient brain delivery through the ABC platform, supporting low projected efficacious dose.

• Preserved full IgG1 Fc effector function, designed to maximize recruitment of brain immune cells for efficient amyloid plaque clearance.

• A proprietary transferrin receptor (TfR)-binding epitope designed to maintain brain delivery while reducing hematologic adverse effects associated with targeting TfR with a full Fc effector function.

• A favorable preclinical safety profile to support the planned clinical study, with no observed adverse effects and only transient, reversible, non-adverse hematological findings with SC dosing.

• Supportive pharmacokinetic and formulation characteristics intended to enable convenient monthly subcutaneous administration using a high-concentration formulation.

• High-productivity manufacturability, with an identified stable, high-expressing cell line designed to support efficient large-scale manufacturing and commercial scalability.

ABC-Enabled siRNA Platform

• Alector continues to advance its ABC-enabled siRNA platform, designed for peripheral dosing and offering the potential for more convenient administration compared with traditional intrathecal delivery, as well as the potential for homogeneous drug distribution throughout the brain.

AL064/AL164

• Alector’s lead siRNA program, AL064/AL164, is a tau siRNA program for AD and other tauopathies and aims to reduce toxic tau protein expression and slowing of cognitive decline in AD.

• AL064 demonstrated robust tau mRNA knockdown and durable reduction of

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8-K

false000165308700016530872026-02-252026-02-25

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): February 25, 2026

Alector, Inc. (Exact name of Registrant as Specified in Its Charter)

Delaware

001-38792

82-2933343

(State or Other Jurisdiction of Incorporation)

(Commission File Number)

(IRS Employer Identification No.)

131 Oyster Point Blvd. Suite 600

South San Francisco, California

94080

(Address of Principal Executive Offices)

(Zip Code)

Registrant’s Telephone Number, Including Area Code: (415) 231-5660

(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: ☐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

Common Stock

ALEC

The Nasdaq Stock Market LLC

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 ☐ 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. ☐

Item 2.02 Results of Operations and Financial Condition. On February 25, 2026, Alector, Inc. (the “Company”) announced its financial results for the quarter ended December 31, 2025. A press release announcing these results, which is attached hereto as Exhibit 99.1, is incorporated herein by reference. All of the information furnished in Item 2.02 and Item 9.01 (including Exhibit 99.1) shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, and shall not be incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended, except as shall be expressly set forth by specific reference in such a filing. Item 9.01 Financial Statements and Exhibits. (d) Exhibits

Exhibit No.

Description

99.1

Press Release dated February 25, 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 thereunto duly authorized.

ALECTOR, INC.

Date:

February 25, 2026

By:

/s/ Arnon Rosenthal

Arnon Rosenthal, Ph.D. Co-founder and Chief Executive Officer