On August 25, 2021, the Company entered into a royalty purchase agreement with certain entities managed by HCR for up to $325.0 million. Under the terms of the agreement, the Company received gross proceeds of $225.0 million upon closing (the “First Investment Amount”) and received an additional $75.0 million during the year ended December 31, 2023 upon the first commercial sale of ZYNLONTA in the United Kingdom or any European Union country (the “Second Investment Amount”) and together with the First Investment Amount, the “Investment Amount”).

The table below provides a rollforward of the Company’s debt obligation relating to the royalty purchase agreement.


(in thousands)
Liability balance at January 1, 2024	$	309,613
Less: royalty payments	5,384
Plus: interest expense	33,608
Less: cumulative catch-up adjustment, Other, net	11,178
Liability balance at December 31, 2024	326,659

Less: royalty payments	3,220
Plus: interest expense	17,168
Less: cumulative catch-up adjustment, Other, net	196
Liability balance at June 30, 2025	$	340,411