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

June 14, 2018

Date of Report (Date of earliest event reported)

PARATEK PHARMACEUTICALS, INC.

(Exact name of Registrant as specified in its charter)

(617) 807-6600

(Registrant’s telephone number, including area code)

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:

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-2of the Securities Exchange Act of 1934 (§ 240 12b-2 of this chapter).

Emerging Growth Company ☐

If an emerging growth company, indicate by a 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 5.07  Submission of Matters to a Vote of Security Holders.

The 2018 Annual Meeting of Stockholders (the “Annual Meeting”) of Paratek Pharmaceuticals, Inc. (the “Company”) was held on June 14, 2018. Proxies for the Annual Meeting were solicited by the Company’s Board of Directors (the “Board”) pursuant to Section 14(a) of the Securities Exchange Act of 1934, as amended, and there was no solicitation in opposition to the Board’s solicitation. There were 31,596,149 shares of common stock entitled to vote at the Annual Meeting. A total of 26,790,571 shares of common stock were represented at the Annual Meeting in person or by proxy. The final votes on the proposals presented at the meeting were as follows:

Proposal No. 1 – Election of Directors

Rolf K. Hoffmann, Kristine Peterson and Jeffrey Stein, Ph.D. were elected as directors to hold office until the 2021 Annual Meeting of Stockholders and until their successors have been duly elected and qualified, or, if sooner, until each director’s death, resignation, or removal, by the following vote:

Proposal No. 2 – Approval of the Paratek Pharmaceuticals, Inc. 2018 Employee Stock Purchase Plan

The Company’s stockholders approved the Paratek Pharmaceuticals, Inc. 2018 Employee Stock Purchase Plan by the following vote:

Proposal No. 3 – Ratification of Selection of Independent Registered Public Accounting Firm

The Company’s stockholders ratified the selection by the Audit Committee of the Board of Ernst & Young LLP as the Company’s independent registered public accounting firm for the year ending December 31, 2018 by the following vote:

(d) Exhibits.

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.