Segment Information

12 Months Ended

Dec. 31, 2025

Segment Reporting [Abstract]

Segment Information

Note 15—Segment Information

The Company’s Chief Executive Officer (“CEO”) is the Chief Operating Decision Maker (“CODM”). The CODM allocates resources and makes operating decisions based on financial information presented on a consolidated basis. The CODM does not evaluate profitability below the level of the consolidated company. Accordingly, the Company has determined that it has a single reportable segment and operating segment structure. The Company views its operations and manages its business as a single operating segment, the gene therapy segment, which is the business of developing AAV-based gene therapies for the treatment of rare monogenic diseases of the central nervous system.

The gene therapy segment derives revenue solely from the Astellas Agreements (see Note 7). The accounting policies of the gene therapy segment are the same as those described in the summary of significant accounting policies.

The CODM reviews significant segment expenses including direct program expenses and compensation expenses as part of the assessment of segment profit and loss. The measure of segment assets is reported on the balance sheet as total consolidated assets.

The following table presents significant segment expenses for the years ended December 31, 2025 and 2024 (in thousands):

	For the Twelve Months Ended December 31,
	2025			2024
Revenue	$	9,773		$	8,333
Less:
Research and development program expense
Program expense		37,887			24,646
Consultants and contractors expense		12,175			15,204
Compensation expense		47,680			36,372
Other segment expense(a)		21,026			21,409
Consolidated net loss	$	(108,995	)	$	(89,298	)
(a) Other segment expense included in consolidated net loss includes interest income, depreciation, insurance, travel, software and subscription services, legal, professional and consulting expense, rent and facilities expense, other general and administrative expense, impairment of long-lived assets, change in fair value of term loan, change in fair value of warrant liability and other expense.