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 5, 2018

PULMATRIX, INC.

(Exact name of registrant as specified in its charter)

99 Hayden Avenue, Suite 390

Lexington, MA 02421

(Address of principal executive offices) (Zip Code)

Registrant’s telephone number, including area code: (781) 357-2333

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 ( see General Instruction A.2. below):

Indicate by check mark whether the registrant is an emerging growth company in 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.  ☐

To the extent required by Item 3.03 of Form 8-K, the information contained in Items 5.03 and 5.07 of this report is incorporated herein by reference.

On June 5, 2018, Pulmatrix, Inc. (the “Company”) held its 2018 annual meeting of stockholders (the “Annual Meeting”). At the Annual Meeting, the stockholders approved an amendment (the “Plan Amendment”) to the Company’s Amended and Restated 2013 Employee, Director and Consultant Equity Incentive Plan (the “Plan”) to (i) increase the total number of shares of common stock authorized for issuance under such plan from 5,096,675 to 12,500,000 shares and (ii) modify such plan’s “evergreen” provision by removing the cap on the number of shares that may be reserved for issuance, so that on January 1st of each year, commencing on January 1, 2019, the number of shares reserved for issuance under such plan will automatically increase by 5% of the number of outstanding shares of common stock on such date. The Plan Amendment had been previously approved by the Company’s board of directors (the “Board”) on April 12, 2018, subject to stockholder approval.

For more information about the Plan Amendment and the Plan, see the Company’s definitive proxy statement for the Annual Meeting, filed with the Securities and Exchange Commission on April 26, 2018 (the “2018 Proxy”), the relevant portions of which are incorporated herein by reference. The description of the Plan Amendment above and such portions of the 2018 Proxy are qualified in their entirety by reference to the full text of the Plan Amendment, filed as Exhibit 10.1 to this Current Report on Form 8-K and incorporated herein by reference.

Also at the Annual Meeting, the stockholders approved an amendment to the Company’s Amended and Restated Certificate of Incorporation (the “Certificate Amendment”). The Certificate Amendment had been previously approved by the Board on April 12, 2018, subject to stockholder approval. Immediately following the Annual Meeting on June 5, 2018, the Company filed with the Secretary of State of the State of Delaware the Certificate Amendment, thereby increasing the number of authorized shares of common stock from 100,000,000 to 200,000,000 shares.

For more information about the Certificate Amendment, see the 2018 Proxy, the relevant portions of which are incorporated herein by reference. A copy of the Certificate Amendment is attached as Exhibit 3.1 hereto and incorporated herein by reference.

On June 5, 2018, the Company held the Annual Meeting. At the Annual Meeting, the following six proposals were submitted to the Company’s stockholders:

For more information about the foregoing proposals, see the 2018 Proxy, the relevant portions of which are incorporated herein by reference. Holders of the Company’s common stock were entitled to one vote per share. The number of votes cast for and against and the number of abstentions and broker non-votes with respect to each matter voted upon are set forth below.

The results reported above are final voting results. No other matters were considered or voted upon at the meeting.

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.