Segment Information

12 Months Ended

Dec. 31, 2025

Segment Reporting [Abstract]

Segment Information

Segment Information

Operating segments are defined as components of an entity for which separate financial information is available and that is regularly reviewed by the CODMs in deciding how to allocate resources and in assessing performance. The Company’s CODMs are (i) the Chief Executive Officer and (ii) the President and Chief Financial Officer. The Company is a clinical stage biotechnology company that operates as a single operating segment and has one reportable segment. In addition to reviewing the expenses in the consolidated statement of operations, the CODMs are provided with research and development costs for Rett syndrome, Batten disease, Early Discovery and Discontinued Programs, as well as categorized general and administrative expenses. The research and development programs are considered significant by the Company. The CODM assesses the financial performance of the segment and decides how to allocate resources based on net loss on a consolidated basis. The measure of segment assets is reported on the condensed consolidated balance sheets as total consolidated assets. The CODMs also assess performance of the segment according to preclinical and clinical data, the stage of development of the research and development programs, along with program specific expenses and market conditions in the pharmaceutical and biotechnology sectors.

As of December 31, 2025 and 2024, the Company did not have any significant long-lived assets located outside of the United States. Information on the segment and reconciliation to net loss is as follows (in thousands):

	Year Ended December 31,
	2025		2024
Revenue under licensing agreements	$	—	$	925
Program specific expenses:
Rett syndrome	25,841		12,104
Batten disease	1,513		5,869
Early Discovery	3,223		5,401
Unallocated internal expenses:
Personnel-related	21,493		18,476
Stock-based compensation	6,472		4,506
Manufacturing	13,018		12,098
Other (a)	3,451		2,463
Total research and development expenses	$	75,011	$	60,917
General and administrative specific expenses:
Personnel-related	$	9,257	$	8,098
Stock-based compensation	7,711		3,813
Professional and consultant fees	4,586		4,558
Office-related	2,465		2,534
Other (b)	4,298		3,610
Total general and administrative expenses	$	28,317	$	22,613
Other income (c)	12,977		7,461
Net loss	$	(90,351)	$	(75,144)
(a) The Other expense segment items category within research and development expense is mainly comprised of: Consultant fees for programs not specified above, IT Software and network support and rent expenses. (b) The Other expense segment items category within general and administrative expense is mainly comprised of: Insurance, IT software and network support, market research, and tax expenses. (c) Other income (expense) included in net loss includes interest income, interest expense, other income and other expense.