Licensed rights and other intangible assets

12 Months Ended

Dec. 31, 2021

Goodwill And Intangible Assets Disclosure [Abstract]

Licensed rights and other intangible assets

6. Licensed rights and other intangible assets

The following provides information about our license rights and other intangible assets, net (in thousands):

	As of December 31, 2021						As of December 31, 2020
	Gross						Gross
	Carrying		Accumulated				Carrying		Accumulated
	Amount		Amortization		Net		Amount		Amortization		Net
License rights and other intangible assets    subject to amortization:
License rights	$	40,000	$	6,826	$	33,174	$	40,000	$	3,803	$	36,197
Hormone therapy drug patents		5,834		1,042		4,792		4,045		749		3,296
Hormone therapy drug patents applied    and pending approval		2,020		—		2,020		1,629		—		1,629
License rights and other intangible assets    subject to amortization		47,854		7,868		39,986		45,674		4,552		41,122
Intangible assets not subject to amortization:
Trademarks/trade name rights		332		—		332		323		—		323
License rights and other intangible assets, net	$	48,186	$	7,868	$	40,318	$	45,997	$	4,552	$	41,445

We recorded amortization expense related to the exclusive license rights agreement with Population Council of $3.0 million for 2021 and 2020, and $0.8 million for 2019. We recorded amortization expense related to patents of $0.3 million for 2021 and 2020, and $0.2 million for 2019.

Our license rights and other intangible assets subject to amortization is expected to be amortized as follows (in thousands):

Year ending December 31,
2022	$	3,451
2023		3,445
2024		3,447
2025		3,445
2026		3,445
Thereafter		20,733
Total	$	37,966

We use a combination of qualitative and quantitative factors to assess licensed rights and intangible assets for impairment. As a result of performing these assessments, we determined that no impairment existed as of December 31, 2021, therefore, no write downs were recorded to our licensed rights and other intangible assets for 2021. For 2020 and 2019, we wrote off $1.1 million and $0.1 million, respectively, in costs related to patents and trademarks, which were included in general and administrative expenses in the accompanying consolidated statements of operations.