ASMB

8-K

false000142680000014268002025-11-102025-11-10

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): November 10, 2025

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

Delaware

001-35005

20-8729264

(State or Other Jurisdiction of Incorporation)

(Commission File Number)

(IRS Employer Identification No.)

Two Tower Place, 7th Floor, South San Francisco, California

94080

(Address of Principal Executive Offices)

(Zip Code)

Registrant’s Telephone Number, Including Area Code: (833) 509-4583 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(s)

Name of each exchange on which registered

Common Stock, par value $0.001

ASMB

The Nasdaq Global Select Market

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 November 10, 2025, Assembly Biosciences, Inc. (the “Company”) issued a press release announcing its financial results for the quarter ended September 30, 2025. A copy of the press release is attached hereto as Exhibit 99.1. The information furnished with this Item 2.02, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any other filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing. Item 9.01 Financial Statements and Exhibits. (d) Exhibits.

Exhibit Number

Description

99.1

Press Release dated November 10, 2025.

104

Cover Page Interactive Data File (embedded within the Inline XBRL document)

1

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.

Assembly Biosciences, Inc.

Date: November 10, 2025

By:

/s/ John O. Gunderson

John O. Gunderson

VP, General Counsel and Corporate Secretary

2

8-K

0001426800false00014268002025-08-062025-08-06

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): August 6, 2025

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

Delaware

001-35005

20-8729264

(State or Other Jurisdiction of Incorporation)

(Commission File Number)

(IRS Employer Identification No.)

Two Tower Place, 7th Floor, South San Francisco, California

94080

(Address of Principal Executive Offices)

(Zip Code)

Registrant’s Telephone Number, Including Area Code: (833) 509-4583 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(s)

Name of each exchange on which registered

Common Stock, par value $0.001

ASMB

The Nasdaq Global Select Market

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 August 6, 2025, Assembly Biosciences, Inc. (the “Company”) issued a press release announcing its financial results for the quarter ended June 30, 2025. A copy of the press release is attached hereto as Exhibit 99.1. The information furnished with this Item 2.02, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any other filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing. Item 8.01 Other Events. On August 6, 2025, the Company issued a press release announcing interim results from the Phase 1a clinical study evaluating ABI-6250, an investigational orally bioavailable, small molecule hepatitis delta virus (HDV) entry inhibitor candidate. A copy of the press release is attached as Exhibit 99.2 and is incorporated herein by reference. Item 9.01 Financial Statements and Exhibits. (d) Exhibits. The exhibits shall be deemed to be filed or furnished, depending on the relevant item requiring such exhibit, in accordance with the provisions of Item 601 of Regulation S-K (17 CFR 229.601)and Instruction B.2 to this form.

Exhibit Number

Description

99.1

Press Release dated August 6, 2025.

99.2

Press Release dated August 6, 2025.

104

Cover Page Interactive Data File (embedded within the Inline XBRL document)

1

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.

Assembly Biosciences, Inc.

Date: August 6, 2025

By:

/s/ John O. Gunderson

John O. Gunderson

VP, General Counsel and Corporate Secretary

2

8-K

false000142680000014268002025-05-082025-05-08

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): May 8, 2025

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

Delaware

001-35005

20-8729264

(State or Other Jurisdiction of Incorporation)

(Commission File Number)

(IRS Employer Identification No.)

Two Tower Place, 7th Floor, South San Francisco, California

94080

(Address of Principal Executive Offices)

(Zip Code)

Registrant’s Telephone Number, Including Area Code: (833) 509-4583 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(s)

Name of each exchange on which registered

Common Stock, par value $0.001

ASMB

The Nasdaq Global Select Market

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 May 8, 2025, Assembly Biosciences, Inc. issued a press release announcing its financial results for the quarter ended March 31, 2025. A copy of the press release is attached hereto as Exhibit 99.1. The information furnished with this Item 2.02, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any other filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing. Item 9.01 Financial Statements and Exhibits. (d) Exhibits.

Exhibit Number

Description

99.1

Press Release dated May 8, 2025.

104

Cover Page Interactive Data File (embedded within the Inline XBRL document)

1

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.

Assembly Biosciences, Inc.

Date: May 8, 2025

By:

/s/ John O. Gunderson

John O. Gunderson

VP, General Counsel and Corporate Secretary

2