As of March 31, 2025, the Company had a definite-lived intangible asset, net related to the acquisition of OLPRUVA of $60.0 million. This was amortized on a straight-line basis over the OLPRUVA patent life of 13 years and was reviewed periodically for impairment. Amortization expense was recorded as intangible asset amortization in the unaudited condensed consolidated statements of operations and was $1.3 million for the three months ended March 31, 2025. The definite-lived intangible assets that are subject to amortization were reviewed for impairment whenever events or changes in circumstances indicate that their carrying amounts may not be recoverable. In the first quarter of 2025, the Company's historical sales experience related to OLPRUVA resulted in management preparing an estimate of future cash flows used to assess the recoverability of such asset. Future cash flows specific to OLPRUVA, which most significantly included an estimate of forecasted revenues, are based on reasonable and supportable assumptions regarding the cash flows expected to result from the use of the asset and its eventual disposition. As a result of the Company's analysis, the asset was deemed to be fully recoverable and no impairments were recorded by the Company for the three months ended March 31, 2025.

In the second quarter of 2025, the Company assessed the results of its refined commercial efforts related to OLPRUVA. This was determined to be a triggering event that could result in a decrease in future expected cash flows, and thus indicated the carrying amount of the OLPRUVA asset group may not be fully recoverable. The Company performed an undiscounted cash flow analysis over the OLPRUVA asset group and determined that the carrying value of the asset group was not recoverable. The Company then estimated the fair value of the asset group to measure the impairment loss for the period. The fair value measurement was based on Level 3 inputs including projected sales driven by market share and product sales price estimates, associated expenses, growth rates, and the discount rate used to measure the fair value of the net cash flows associated with this asset group. The Company recorded an intangible asset impairment charge in the second quarter of 2025, which resulted in reducing the OLPRUVA intangible asset value to zero.

In connection with the XOMA License Agreement, a regulatory milestone payment of $6.0 million was due to XOMA upon approval of MIPLYFFA in the United States, which the Company paid in October 2024. This definite-lived intangible asset is amortized on a straight-line basis over the MIPLYFFA patent life of approximately five years and is reviewed periodically for impairment. Amortization expense is recorded as intangible asset amortization in the unaudited condensed consolidated statements of operations and was $0.3 million for both the three months ended March 31, 2026, and 2025.