X0508 4 2025-06-09 0001521036 Lantheus Holdings, Inc. LNTH 0001754976 Marshall Robert J. Jr. C/O LANTHEUS HOLDINGS, INC. 201 BURLINGTON ROAD, SOUTH BUILDING BEDFORD MA 01730 0 1 0 0 CFO and Treasurer 1 Common Stock 2025-06-09 4 M 0 14773 49.93 A 128633 D Common Stock 2025-06-09 4 S 0 3494 81.2707 D 125139 D Common Stock 2025-06-09 4 S 0 9243 82.5023 D 115896 D Common Stock 2025-06-09 4 S 0 27036 83.3987 D 88860 D Stock Option (right to buy) 49.93 2025-06-09 4 M 0 14773 0 D 2032-03-03 Common Stock 14773 0 D The transactions reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 7, 2025. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $80.915 to $81.78, inclusive. The reporting person undertakes to provide to Lantheus Holdings, Inc. ("LNTH"), any security holder of LNTH or the staff of the Securities and Exchange Commission ("SEC"), upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (2) to this Form 4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $81.984 to $82.977, inclusive. The reporting person undertakes to provide to LNTH, any security holder of LNTH or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (3) to this Form 4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $82.997 to $83.98, inclusive. The reporting person undertakes to provide to LNTH, any security holder of LNTH or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (4) to this Form 4. 100% of the shares subject to the option are fully vested and exercisable. /s/ Eric M. Green, attorney-in-fact 2025-06-11