The Company’s segment determination is based on the financial results that are regularly evaluated by the Company’s chief operating decision maker ("CODM") to determine resource allocation and assess performance. The Company's CODM is its chief executive officer. The Company has one operating and one reportable segment. Net long-lived assets are all physically located in the United States and the total assets of the segment equal the total assets presented on the condensed consolidated balance sheet. The primary financial measure by which the CODM evaluates the business is net loss. The CODM uses net loss to monitor budget versus actual results to assess performance of the segment. A summary of the significant segment expenses reported to the CODM are shown below for the three months ended March 31, 2026 and 2025:


	Three Months Ended March 31,
(in thousands)	2026			2025
Operating Expenses
Z-rostudirsen (DMD)	$	37,747		$	21,093
Z-basivarsen (DM1)		14,782			45,434
Platform and external research and development		11,465			8,235
Personnel related		28,555			20,701
Stock-based compensation		13,081			13,020
Facility-related and other		11,860			6,916
Professional and consulting fees		7,786			6,973
Interest income		(8,757	)		(7,100	)
Interest expense		4,202			—
Other expense (income), net		133			89
Net loss	$	120,854		$	115,361

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

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+ Details