Liability Related to Sale of Future Royalties (Tables)

12 Months Ended

Dec. 31, 2021

Liability Related To Sale Of Future Royalties [Abstract]

Schedule of Activity Within Liability Related to Sale of Future Royalties

The following table presents the changes in the liability related to the sale of future royalties under the Royalty Purchase Agreement with HCR (in thousands):

	Liability Related to
	Sale of Future Royalties
Proceeds from sale of future royalties in December 2020	$	196,000
Deferred transaction costs		(3,473	)
Interest expense recognized		771
Balance at December 31, 2020		193,298
Zolgensma royalties paid to HCR		(48,226	)
Interest expense recognized		26,277
Balance at December 31, 2021		171,349
Current portion of liability related to sale of future royalties		(37,889	)
Liability related to sale of future royalties, non-current	$	133,460