LNTH

8-K

0001521036false00015210362026-02-262026-02-26

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): February 26, 2026

LANTHEUS HOLDINGS, INC.

(Exact name of Registrant as Specified in Its Charter)

Delaware

001-36569

35-2318913

(State or Other Jurisdiction of Incorporation)

(Commission File Number)

(IRS Employer Identification No.)

201 Burlington Road South Building

Bedford, Massachusetts

01730

(Address of Principal Executive Offices)

(Zip Code)

Registrant’s Telephone Number, Including Area Code: (978) 671-8001

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 $0.01 per share

LNTH

The Nasdaq Global 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 February 26, 2026, Lantheus Holdings, Inc. (the “Company”) announced via press release its financial results as of and for the three and twelve months ended December 31, 2025. A copy of that press release is being furnished as Exhibit 99.1 and is hereby incorporated by reference. The information furnished pursuant to 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 under that Section and shall not be deemed to be incorporated by reference into any filing of the Company under the Securities Act of 1933, as amended (the “Securities Act”), or the Exchange Act, except as shall be expressly set forth by specific reference in such filing. Item 9.01 Financial Statements and Exhibits. (d) Exhibits

Exhibit No.

Description

99.1*

Press release of Lantheus Holdings, Inc. dated February 26, 2026, entitled “Lantheus Reports Fourth Quarter and Full Year 2025 Financial Results and Provides Business Update”

104

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

* Exhibits 99.1 attached hereto are being furnished and shall not be deemed “filed” for purposes of Section 18 of the Exchange Act, as amended, or otherwise subject to the liabilities of that section, nor shall such information be deemed incorporated by reference in any filing under the Securities Act or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

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.

LANTHEUS HOLDINGS, INC.

By:

/s/ Daniel M. Niedzwiecki

Name:

Daniel M. Niedzwiecki

Title:

Chief Administrative Officer and General Counsel

Date: February 26, 2026

8-K

0001521036false00015210362025-10-312025-10-31

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): October 31, 2025

LANTHEUS HOLDINGS, INC.

(Exact name of Registrant as Specified in Its Charter)

Delaware

001-36569

35-2318913

(State or Other Jurisdiction of Incorporation)

(Commission File Number)

(IRS Employer Identification No.)

201 Burlington Road South Building

Bedford, Massachusetts

01730

(Address of Principal Executive Offices)

(Zip Code)

Registrant’s Telephone Number, Including Area Code: (978) 671-8001

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 $0.01 per share

LNTH

The Nasdaq Global 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 6, 2025, Lantheus Holdings, Inc. (the “Company”) announced via press release its financial results as of and for the three and nine months ended September 30, 2025. A copy of that press release is being furnished as Exhibit 99.1 and is hereby incorporated by reference. The information furnished pursuant to 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 under that Section and shall not be deemed to be incorporated by reference into any filing of the Company under the Securities Act of 1933, as amended (the “Securities Act”), or the Exchange Act, except as shall be expressly set forth by specific reference in such filing. Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers On November 6, 2025, the Company announced that Brian Markison, the Company’s Chief Executive Officer and a member of the Company’s board of directors (the “Board”), notified the Board on November 2, 2025, that he will retire from the Company effective December 31, 2025 (the “Effective Date”). In connection with his retirement and in accordance with the terms of his employment agreement with the Company, Mr. Markison will also resign from the Board on the Effective Date. Mr. Markison’s decision to retire from all positions held at the Company is not related to any disagreement with the Company on any matter relating to its operations, policies, or practices. Mr. Markison has agreed to serve as a strategic advisor to the Company through at least March 31, 2026. The Company has also announced that Mary Anne Heino, the Chair of the Board, has been appointed Executive Chair of the Company effective on November 7, 2025 (the “Appointment Date”) and will serve as the Company’s principal executive officer as of the Appointment Date. In addition, the Board appointed Ms. Heino as the Company’s Interim Chief Executive Officer effective on January 1, 2026. Ms. Heino, 65, has served as a member of the Board since August 2015, and became the Chair of the Board and a member of the Science and Technology Committee in March 2024. She previously served in the following roles at the Company: Chief Executive Officer from August 2015 until March 1, 2024; President from August 2015 until March 2023; Chief Operating Officer from March 2015 until August 2015; and Chief Commercial Officer from April 2013 (when she joined the Company) until March 2015. Ms. Heino was not selected as Executive Chair or Interim Chief Executive Officer pursuant to any arrangement or understanding between her and any other person. There are no related party transactions between the Company and Ms. Heino, except that she

8-K

0001521036false00015210362025-08-062025-08-06

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 06, 2025

LANTHEUS HOLDINGS, INC.

(Exact name of Registrant as Specified in Its Charter)

Delaware

001-36569

35-2318913

(State or Other Jurisdiction of Incorporation)

(Commission File Number)

(IRS Employer Identification No.)

201 Burlington Road South Building

Bedford, Massachusetts

01730

(Address of Principal Executive Offices)

(Zip Code)

Registrant’s Telephone Number, Including Area Code: (978) 671-8001

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 $0.01 per share

LNTH

The Nasdaq Global 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, Lantheus Holdings, Inc. (the “Company”) announced via press release its financial results as of and for the three and six months ended June 30, 2025. A copy of that press release is being furnished as Exhibit 99.1 and is hereby incorporated by reference. The information furnished pursuant to 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 under that Section and shall not be deemed to be incorporated by reference into any filing of the Company under the Securities Act of 1933, as amended (the “Securities Act”), or the Exchange Act, except as shall be expressly set forth by specific reference in such filing. Item 7.01 Regulation FD Disclosure. On August 6, 2025, the Company issued a press release announcing that the United States Food and Drug Administration has accepted a new drug application for a new formulation of its piflufolastat F-18 prostate-specific membrane antigen positron emission tomography imaging agent filed by its affiliate, Aphelion LLC. A copy of the press release is being furnished with this Current Report on Form 8-K as Exhibit 99.2 and is incorporated herein by reference. The information in this Item 7.01, including Exhibit 99.2, shall not be deemed “filed” for purposes of Section 18 of the Exchange Act or otherwise subject to the liabilities under that Section and shall not be deemed to be incorporated by reference into any filing of the Company under the Securities Act or the Exchange Act, except as shall be expressly set forth by specific reference in such filing. Item 8.01 Other Events. On August 6, 2025, the Company announced that its board of directors has authorized a program to repurchase up to $400.0 million of shares of its common stock through December 31, 2027 (the “2025 Program”). The 2025 Program replaces the Company’s existing repurchase program, which was announced in November 2024. Repurchases under the 2025 Program may be made from time to time through open market transactions at prevailing market prices, in privately negotiated transactions and/or through other legally permissible means, depending on market conditions and in accordance with applicable rules and regulations. The actual timing, number, and dollar amount of repurchase transactions will be determined by the Company’s management at its discretion and will depend on a number of factors including, but not limited to, the market price of the Company’s common stock. The Company may also establish 10b5-1 trading plans from time to time that will provide flexibility if and when it buys back its common stock. The announcement of the 2025 Program is included in the press release attached hereto as Exhibit 99.1.

Safe Harbor for Forward-Looking and Cautio