6.Intangible Assets

Intangible assets consist of the acquired IPR&D intangible asset related to the lonigutamab product candidate acquired in the ACELYRIN Merger at its estimated fair value of $51.0 million as of the Closing Date. See Note 3 for additional information. The asset is classified as an indefinite-lived intangible asset and, accordingly, is not amortized but is subject to annual impairment testing, or more frequently if events or changes in circumstances indicate that the asset may be impaired.

In May 2026, the Company completed its strategic review of the lonigutamab program and decided to pursue strategic alternatives for the program. This decision represented a triggering event under ASC 350 and required the Company to perform an interim impairment assessment of the acquired IPR&D intangible asset. Based on the results of the impairment assessment, the Company recorded an intangible assets impairment loss of $41.8 million, which was recognized as a separate line item in operating expenses, in its unaudited condensed consolidated statement of operations and

comprehensive income (loss) for the three and six months ended June 30, 2026. The impairment loss reduced the carrying value of the acquired IPR&D intangible asset to its estimated fair value of $9.1 million as of June 30, 2026.

The fair value of the acquired IPR&D intangible asset was determined using a weighted scenario-based, risk-adjusted discounted cash flows method, which estimates the present value of projected future cash flows attributable to the asset under multiple potential outcomes and applies probability weightings ranging from 10% to 70%. The valuation incorporated significant unobservable inputs and assumptions including the probability and timing of potential strategic transactions, such as out-licensing arrangements, estimated future cash flows, projected revenues, the probability of technical and regulatory success and a discount rate of 24%.