8-K

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): September 29, 2026

Tectonic Therapeutic, Inc.

(Exact name of registrant as specified in its charter)

Delaware

001-38537

81-0710585

(state or other jurisdiction

of incorporation)

(Commission

File Number)

(I.R.S. Employer

Identification No.)

490 Arsenal Way, Suite 200

Watertown, Massachusetts

02472

(Address of principal executive offices)

(Zip Code)

Registrant’s telephone number, including area code: (339) 666-3320

Not applicable

(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

Name of each exchange

on which registered

Common Stock, $0.0001 par value per share

TECX

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 8.01

Other Events.

On September 29, 2026, Tectonic Therapeutic, Inc. issued a press release titled “Tectonic Therapeutic Announces Favorable Phase 1 Safety, Tolerability and PK Results for TX2100, a Novel Approach for the Treatment of Hereditary Hemorrhagic Telangiectasia (HHT)”. A copy of the press release is attached as Exhibit 99.1 to this Current Report on Form 8-K and, other than the quotes contained therein, is incorporated herein by reference.

Item 9.01

Financial Statements and Exhibits.

(d) Exhibits


Exhibit No.		Description

99.1		Press Release dated September 29, 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.


TECTONIC THERAPEUTIC, INC.

By:		/s/ Daniel Lochner
		Daniel Lochner
		Chief Financial Officer

Dated: September 29, 2026