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Balance Sheet Components

9 Months Ended

Sep. 30, 2025

Balance Sheet Components

Balance Sheet Components

6.Balance Sheet Components

Restricted Cash

Restricted cash includes cash held at financial institutions that is pledged as collateral for stand-by letters of credit, of $1.4 million and $1.1 million related to lease commitments as of September 30, 2025 and December 31, 2024, respectively. The cash will be restricted until the termination or modification of the related lease agreements. Restricted cash is classified as restricted cash, non-current in the condensed consolidated balance sheets as of September 30, 2025 and December 31, 2024.

Other Prepaid Expenses and Current Assets

Other prepaid expenses and current assets consisted of the following as of September 30, 2025 and December 31, 2024 (in thousands):

​	​	​	​	​	​	​
​		September 30,			December 31,
​	​	2025		​	2024
Prepaid credit voucher for clinical manufacturing	​	$	3,222	​	$	—
Interest receivable	​	​	1,987	​	​	698
Prepaid subscriptions	​	​	1,657	​	​	1,232
Tax receivable	​	​	1,650	​	​	1,114
Prepaid insurance	​	​	1,094	​	​	695
Other	​		1,001	​		762
Total other prepaid expenses and current assets	​	$	10,611	​	$	4,501

​

The prepaid credit voucher for clinical manufacturing was received by ACELYRIN in the third quarter of 2024 as part of an agreement to cancel certain services with a vendor under a manufacturing agreement related to the suspension of development of certain ACELYRIN programs. The prepaid credit voucher for clinical manufacturing may be used to settle invoices for services and raw materials from this vendor related to the lonigutamab product candidate in development by ACELYRIN. As of September 30, 2025, the prepaid credit voucher for clinical manufacturing included $3.2 million classified in other prepaid expenses and current assets and $5.2 million included in other assets, non-current.

​

Property and Equipment, Net

Property and equipment, net consisted of the following as of September 30, 2025 and December 31, 2024 (in thousands):

​	​	​	​	​	​	​	​	​
​		Estimated Useful Life		September 30,			December 31,
​	​	(in years)	​	2025		​	2024
Leasehold improvements		Shorter of useful life or lease term	​	$	17,655	​	$	17,618
Laboratory equipment		5	​	​	5,844	​	​	5,227
Furniture and fixtures		5	​		1,709	​		1,709
Computer equipment		5	​		896	​		896
Capitalized software		3	​		75	​		75
Total property and equipment, gross	​	​	​		26,179	​		25,525
Less: Accumulated depreciation and amortization	​	​	​		(7,121)	​		(4,557)
Total property and equipment, net	​	​	​	$	19,058	​	$	20,968

​

Depreciation and amortization expense was $0.9 million and $0.8 million for the three months ended September 30, 2025 and 2024, respectively, and $2.6 million and $2.3 million for the nine months ended September 30, 2025 and 2024, respectively.

Other Accrued Expenses and Current Liabilities

Other accrued expenses and current liabilities consisted of the following as of September 30, 2025 and December 31, 2024 (in thousands):

​

​	​	​	​	​	​	​
​		September 30,			December 31,
​	​	2025		​	2024
Accrued personnel and related expenses	​	$	12,167	​	$	7,765
Accrued professional services and other	​		5,217	​		2,657
Severance liability	​	​	1,374	​	​	—
Accrued other expenses	​		63	​		158
Total other accrued expenses and current liabilities	​	$	18,821	​	$	10,580

​

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- Definition

The entire disclosure for supplemental balance sheet disclosures, including descriptions and amounts for assets, liabilities, and equity.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org/210/tableOfContent

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