Intangible Assets

12 Months Ended

Dec. 31, 2021

Intangible Assets

Intangible Assets

5. Intangible Assets

The Company’s intangible assets consist of the following:

	December 31, 2021
		Gross
	Estimated	Carrying		Accumulated				Net Book
	Useful Lives	Value		Amortization		Impairment		Value
Internally developed patents	6–20 years	$	1,079,325	$	(499,828)	$	(579,497)	$	—
Acquired licenses	16–20 years		285,000		(285,000)		—		—
Total intangible assets subject to amortization			1,364,325		(784,828)		(579,497)		—
IPR&D assets	Indefinite		12,418,967		—		—		12,418,967
Total		$	13,783,292	$	(784,828)	$	(579,497)	$	12,418,967

	December 31, 2020
		Gross
	Estimated	Carrying		Accumulated				Net Book
	Useful Lives	Value		Amortization		Impairment		Value
Internally developed patents	6–10 years	$	884,787	$	(479,908)	$	—	$	404,879
Acquired licenses	16–20 years		285,000		(285,000)		—		—
Total intangible assets subject to amortization			1,169,787		(764,908)		—		404,879
IPR&D assets	Indefinite		12,418,967		—		—		12,418,967
Total		$	13,588,754	$	(764,908)	$	—	$	12,823,846

Amortization expense of intangible assets subject to amortization totaled $19,920 and $46,813 for the years ended December 31, 2021 and 2020, respectively. Amortization expense was classified as research and development expenses in the accompanying consolidated statements of operations and comprehensive loss.

Intangible assets subject to amortization, which represent incomplete technologies, was amortized to expense over their estimated useful lives once the underlying technologies were substantially complete. In the event that in the future the Company ceases the development of these assets, the remaining carrying value would be written off at that time. IPR&D assets are periodically assessed for impairment by considering the state of completion of the projects, the remaining activities required to complete development, the anticipated market for the completed products and anticipated future cash required to complete development.

As of December 31, 2021, the Company recorded an impairment loss of $0.6 million for the remaining net book value of the internally developed patents that are associated with the Company's discontinued development programs. The impairment loss has been recorded to research and development expenses in the accompanying audited consolidated statements of operations and comprehensive loss. There was no IPR&D impairment loss during the year ended December 31, 2021 and 2020.