10. OTHER BALANCE SHEET COMPONENTS

Property and equipment

Property and equipment consist of the following (in thousands):

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Depreciation and amortization expense was $0.1 million, $0.2 million and $0.9 million for the years ended December 31, 2024, 2023 and 2022, respectively. Certain property and equipment were either sold, retired or disposed of, which related costs and accumulated depreciation were removed from the balance sheet, and any resulting gain or loss were reflected in statements of operations in the period realized.

Intangible assets

Intangible assets consist of the following (in thousands):

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See “Note 5 – In-Licensing and Acquisition” for related discussions of capitalized intangible assets. For the years ended December 31, 2024, 2023 and 2022, amortization expense recorded within cost of sales in the statements of operations were $2.1 million, $1.1 million and $0.1 million, respectively.

As of December 31, 2024, the weighted average remaining amortization period of outstanding intangible assets was 11.54 years. The following table presents the estimated future amortization expense of intangible assets (in thousands):

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Other accrued liabilities

Other accrued liabilities consist of the following (in thousands):

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