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): June 16, 2025

PULMATRIX, INC.

(Exact name of registrant as specified in its charter)

Delaware

001-36199

46-1821392

(State or other jurisdiction

of incorporation)

(Commission

File Number)

(IRS Employer

Identification No.)

945 Concord Street

Suite 1217

Framingham, Massachusetts

01701

(Address of principal executive offices)

(Zip Code)

Registrant’s telephone number, including area code: (888) 355-4440

N/A

(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 $0.0001 per share		PULM		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. ☐

As previously disclosed, on November 13, 2024, Pulmatrix, Inc., a Delaware corporation (“Pulmatrix” or the “Company”) and Cullgen Inc., a Delaware corporation (“Cullgen”), entered into an Agreement and Plan of Merger and Reorganization, as amended by Amendment No. 1 thereto on April 7, 2025 (the “Merger Agreement”), pursuant to which, and subject to the satisfaction or waiver of the conditions set forth in the Merger Agreement, among other things, PCL Merger Sub, Inc., a direct, wholly owned subsidiary of Pulmatrix, will merge with and into Cullgen, with Cullgen surviving as a wholly owned subsidiary of Pulmatrix, and the surviving corporation of the merger (the “Merger”). Pulmatrix following the Merger is referred to herein as the “Combined Company.”

Item 5.07

Submission of Matters to a Vote of Security Holders

In connection with the Merger, Pulmatrix held a special meeting in lieu of the annual meeting of Pulmatrix stockholders on June 16, 2025, at 8:30 a.m. Eastern Time (the “Special Meeting”), at which the Pulmatrix stockholders voted on the proposals set forth below relating to the Merger Agreement. The proposals are described in detail in the Company’s definitive proxy statement/prospectus filed with the U.S. Securities and Exchange Commission (the “SEC”) and declared effective on May 9, 2025 (as amended, the “Proxy Statement/Prospectus”) and first mailed to the Pulmatrix stockholders on May 9, 2025. The final voting results regarding each proposal are set forth below. There were 3,652,285 shares of Pulmatrix common stock outstanding and entitled to vote on May 1, 2025, the record date for the Special Meeting, and 2,124,526 shares of Pulmatrix common stock were represented in person or by proxy at the Special Meeting, which number constituted a quorum.

Proposal No. 1: To approve (i) the issuance of shares of Pulmatrix common stock, which will represent more than 20% of the shares of Pulmatrix common stock outstanding immediately prior to the Merger, a copy of which is attached as Annex A-1, including the amendment thereto, to the Proxy Statement/Prospectus, to stockholders of Cullgen, pursuant to the terms of the Merger Agreement, and (ii) the change of control resulting from the Merger, pursuant to Nasdaq Listing Rules 5635(a) and 5635(b), respectively (“Proposal No. 1”).

Pulmatrix, Inc. 8-K