Transaction Details

Footnotes

The transaction reported in this Form 4 reflects additional shares of common stock issued by Lantheus Holdings, Inc. to the reporting person upon the vesting of relative Total Shareholder Return performance-based restricted stock units ("PSUs") that were previously granted and included in the Form 3 filed upon the reporting person becoming a Section 16 officer. The number of shares reported in the Form 3 reflected 100% of the target number of shares underlying the PSUs. The number of shares that actually vested under the PSUs equaled 162.8% of the target number of shares. Accordingly, the number of shares reported in this Form 4 reflects the difference between the number of shares that actually vested under the PSUs and the target number of shares originally included in the Form 3.