Intangible assets

12 Months Ended

Dec. 31, 2021

Goodwill and Intangible Assets Disclosure [Abstract]

Intangible assets

Intangible assets

Intangible assets, net of accumulated amortization, are summarized as follows (in thousands):

	As of December 31, 2021
	Cost		Accumulated amortization		Impairment		Net
In-licensed rights	$	5,224	(1,219)		(4,005)		—
Total	$	5,224	$	(1,219)	$	(4,005)	$	—

	As of December 31, 2020(1)
	Cost		Accumulated amortization		Impairment		Net
In-licensed rights	$	5,224	(827)		—		4,397
Total	$	5,224	$	(827)	$	—	$	4,397

(1) Prior period amounts have been retrospectively adjusted to reflect the effects of the Separation.

Amortization expense for intangible assets was $0.4 million, $0.5 million, and $0.3 million for the years ended December 31, 2021, 2020 and 2019, respectively.

In August 2021, the Company announced its decision to focus its efforts on the U.S. market and to execute an orderly wind down of its European operations. In connection with this, in September 2021, the Company recognized an impairment loss of $4.0 million for the remaining unamortized balance of the intangible asset associated with in-licensed rights for the ZYNTEGLO product, which is reflected within cost of product revenue in the consolidated statements of operations and comprehensive loss for the year ended December 31, 2021.