Segment Information

9 Months Ended

Sep. 30, 2026

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 severe monogenic diseases of the central nervous system.

The gene therapy segment derived revenue solely from the Astellas Transactions (see Note 6). 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 three and nine months ended September 30, 2026 and 2025 (in thousands):

	For the Three Months Ended September 30,						For the Nine Months Ended September 30,
	2026			2025			2026			2025
Revenue	$	—		$	—		$	—		$	4,288
Less:
Research and development program expense
Program expense		12,450			14,366			52,778			26,737
Consultants and contractors expense		5,290			2,913			14,536			9,385
Compensation expense		17,338			11,111			49,105			33,231
Other segment expense(a)		4,050			4,343			11,758			16,079
Consolidated net loss	$	(39,128	)	$	(32,733	)	$	(128,177	)	$	(81,144	)
(a) Other segment expense included in consolidated net loss includes interest income, depreciation, insurance, travel, software and subscription services, legal, professional and consulting expense, commercial readiness expense, rent and facilities expense, other general and administrative expense, net gain on lease termination, change in fair value of term loan, change in fair value of warrant liability and other expense.