In 2012, the Company entered into the Ligand License Agreement for a worldwide sublicense to develop, manufacture and commercialize FILSPARI. As consideration for the license, the Company is required to make substantial payments upon the achievement of certain milestones, totaling up to $114.1 million. Through June 30, 2025 the Company has capitalized $47.2 million for contractual milestones achieved under the Ligand License Agreement. Pursuant to the Ligand License Agreement, the Company is obligated to pay to Ligand (and Bristol-Myers Squibb Company ("BMS")) an escalating royalty between 15% and 17% of net sales of FILSPARI and any other products containing FILSPARI or related compounds, with payments due quarterly. The Company began incurring costs associated with such royalties following the February 2023 approval of FILSPARI. For the three and six months ended June 30, 2025, the Company capitalized royalties owed on net sales of FILSPARI to intangible assets of $11.4 million and $20.3 million, respectively, and $4.1 million and $7.0 million, for the three and six months ended June 30, 2024, respectively. The cost of historical milestones paid and royalty payments are being amortized to selling, general and administration on a straight-line basis through April 30, 2033.

In 2014, the Company entered into the Mission License Agreement, pursuant to which it obtained an exclusive, royalty-bearing license to market, sell and commercialize Thiola (tiopronin) in the United States and Canada, and a non-exclusive license to use know-how relating to Thiola to the extent necessary to market Thiola. Under the terms of the Mission License Agreement, as subsequently amended, which runs through May 2029, the Company is obligated to pay Mission the greater of $2.1 million, representing the guaranteed minimum royalty, or 20% of its Thiola net sales generated globally during each calendar year. The Company has capitalized $178.0 million related to the Thiola intangible asset which consists of an up-front license fee, professional fees, present value of the guaranteed minimum royalties and any additional payment obligations through June 30, 2025 in excess of minimum royalties. The Company has not capitalized any royalties in excess of the annual contractual minimum as of June 30, 2025 as royalties are capitalized in the period in which they become probable and estimable, which is typically in the period corresponding with the respective sales.

Amortization expense for the three and six months ended June 30, 2025 was $13.7 million and $26.1 million, respectively, and $9.9 million and $19.2 million, for the three and six months ended June 30, 2024, respectively, recorded in selling, general and administrative expenses.