SEGMENT INFORMATION

9 Months Ended

Sep. 30, 2026

Segment Reporting [Abstract]

SEGMENT INFORMATION

15. SEGMENT INFORMATION

The Company operates in one segment: discovering, developing, manufacturing and delivering therapies to patients with rare diseases. As of September 30, 2026, there have not been material changes in significant expense categories or assets provided to the Company’s CEO, the Company’s chief operating decision maker (the "CODM"). For further details regarding the Company's segment information, please read Note 21, Segment Information of the Annual Report on Form 10-K for the year ended December 31, 2025. The table below includes information about the Company’s segment, including significant segment expenses and a reconciliation to net (loss) income:

	For the Three Months Ended September 30,						For the Nine Months Ended September 30,
	2026			2025			2026			2025
							(in thousands)
Total revenues	$	381,351		$	399,356		$	1,513,405		$	1,755,303
Segment expenses and other segment items:
Cost of sales (excluding amortization of in-licensed rights)		188,512			150,775			446,665			440,897
Compensation and other personnel expenses		62,644			44,428			185,299			227,351
Up-front and collaboration license fees		—			100,000			50,000			683,787
Manufacturing expenses		2,251			33,897			23,846			182,047
Clinical trial expenses		20,511			28,613			61,917			95,271
Facility- and technology-related expenses (excluding depreciation and amortization)		22,940			20,577			69,772			76,814
Restructuring charge		—			40,510			—			40,510
Research and development- other (excluding non-cash items) (1)		17,241			20,883			55,759			81,197
Selling, general and administrative- other (excluding non-cash items) (2)		50,787			41,883			133,442			149,347
Roche collaboration reimbursement		(7,138	)		(12,198	)		(22,496	)		(66,368	)
Other segment items (3)		1,673			(430	)		(842	)		(3,653	)
Gain on debt extinguishment		—			(3,761	)		—			(3,761	)
Loss (gain) on strategic investments		523			(36,739	)		2,683			17,268
Interest expense		21,616			9,460			64,837			19,191
Interest income		(7,086	)		(7,249	)		(19,653	)		(22,693	)
Income tax expense (benefit)		2,695			(14,102	)		18,051			6,634
Depreciation and amortization expense		5,900			18,450			26,903			39,268
Stock-based compensation expense		26,743			14,927			80,614			93,380
Litigation settlement charge		—			—			39,000			—
Segment net (loss) income	$	(28,461	)	$	(50,568	)	$	297,608		$	(301,184	)
Reconciliation of profit or loss
Adjustments and reconciling items		—			—			—			—
Consolidated net (loss) income	$	(28,461	)	$	(50,568	)	$	297,608		$	(301,184	)

(1)Research and development-other includes professional services, pre-clinical expenses and research and other expenses.

(2)Selling, general and administrative-other includes professional services and other expenses.

(3)Other segment items included in segment net (loss) income include accretion of investment discount, net and other, net, as well as items separately presented and not defined as significant expenses below.

Significant expense categories that are regularly provided to the CODM include cost of sales (excluding amortization of in-licensed rights), compensation and other personnel expenses, up-front and collaboration license fees, manufacturing expenses, clinical trial expenses, facility- and technology-related expenses, restructuring charge, research and development- other and selling, general and administrative- other. The other expense or income information are other segment items and include separate presentation of loss (gain) on strategic investments, interest expense, interest income, income tax expense (benefit), depreciation and amortization, stock-based compensation expense and litigation settlement charge, which are included in the measure of segment net (loss) income, but are not significant segment expenses.

Assets provided to the CODM for the single segment are consistent with those reported on the unaudited condensed consolidated balance sheets.