Segment Information

12 Months Ended

Dec. 31, 2024

Segment Information.

Segment Information

16. Segment Information

The Company’s CODM, the Company’s Chief Executive Officer, views the Company’s operations and manages its business as a single operating segment, which is the business of developing and commercializing genetic medicine. The Company therefore has one reportable segment.

The CODM reviews the segment's profit or loss based on net (loss) income reported on the consolidated statement of operations and comprehensive (loss) income and considers forecast-to-actual variances monthly for expenses that are deemed significant in making resource allocation decisions and assessing performance. Further, the CODM reviews the segment's assets based on total assets reported on the consolidated balance sheets. All long-lived assets are held in the United States.

The CODM views specific categories within research and development expenses and general and administrative expenses in totality as significant. Further, the CODM reviews the external research and development expenses of specific programs as significant given the impact on achieving the Company’s corporate goals. The following table

reconciles reported collaboration revenue to net (loss) income under the significant expense principle for the years ended December 31, 2024, 2023, and 2022:

	Year ended December 31, 2024		Year ended December 31, 2023		Year ended December 31, 2022
Collaboration revenue	$	80,001	$	250,008	$	40,907
External research and development (1):
Anti-tau antibody program		15,647		16,923		1,190
SOD1 silencing gene therapy program		15,818		6,251		3,082
Tau silencing gene therapy program		7,455		696		—
Partnered programs (2)		4,985		7,650		3,229
Other programs and platforms (3)		14,176		14,488		14,721
Internal research and development (4)		38,422		27,860		20,505
Facilities and other research and development (5)		30,865		18,304		18,037
General and administrative		35,920		35,822		30,980
Interest income		18,328		11,721		1,792
Other income		622		3		2,653
Income tax provision		665		1,408		16
Net (loss) income	$	(65,002)	$	132,330	$	(46,408)

1)External research and development is allocated to the Company’s programs and platforms, and includes laboratory supplies, and non-employee consultant and contractor costs.

2)Partnered programs include programs in which the Company is collaborating with partners to develop AAV gene therapy products and product candidates under the Company’s 2019 and 2023 Neurocrine Collaboration Agreements, and the 2023 Novartis Collaboration Agreement.

3) Other programs and platforms consist of expenses related to other early research programs and platforms which are not considered quantitatively and qualitatively significant, including capsid discovery, non-viral delivery, and early research programs.

4) Internal research and development consist of employee-related expenses including salaries, benefits, and stock-based compensation expense.

5) Depreciation and amortization are included within facilities and other research and development, which are the same as the amounts in the accompanying consolidated statements of operations as the Company operates as a single operating segment.