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): December 20, 2023

Registrant’s telephone number, including area code: (919) 328-4400

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):

¨ 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:

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 x

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. x

Item 8.01 Other Events.

As previously disclosed, in January 2021, Liquidia Corporation, a Delaware Corporation (the “Company”) filed a petition with the Patent Trial and Appeal Board (“PTAB”) for inter partes review of U.S. Patent No. 10,716,793 (the “’793 Patent”), seeking a determination that the claims in the ‘793 Patent are invalid. In July 2022, the PTAB ruled in our favor, concluding that based on the preponderance of the evidence, all the claims of the ’793 Patent have been shown to be unpatentable due to the existence of prior art cited by the Company in the inter partes review proceedings. In August 2022, United Therapeutics Corporation (“United Therapeutics”) submitted a rehearing request with respect to the PTAB’s decision in the inter partes review of the ‘793 Patent. The rehearing request was denied in February 2023. In April 2023, United Therapeutics appealed the decision of the PTAB with respect to the ‘793 Patent to the United States Court of Appeals for the Federal Circuit. Oral argument on the appeal was held on December 4, 2023.

On December 20, 2023, the Company issued a press release announcing that the United States Court of Appeals for the Federal Circuit affirmed the earlier decision of the PTAB. As a result of the decision, the Company will immediately seek to set aside the injunction issued by the U.S. District Court for the District of Delaware in the lawsuit filed by United Therapeutics under the Drug Price Competition and Patent Term Restoration Act (the “Hatch-Waxman Act”) and pursue final regulatory approval of YUTREPIA by the U.S. Food and Drug Administration.

A copy of the press release is filed as Exhibit 99.1 hereto and is incorporated by reference into this Item 8.01.

Item 9.01 Financial Statements and Exhibits.

(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.