Intangible Assets

6 Months Ended

Jun. 30, 2021

Goodwill And Intangible Assets Disclosure [Abstract]

Intangible Assets

5. Intangible Assets

The Company’s intangible assets consists of the following:

	June 30, 2021
		Gross
	Estimated	Carrying		Accumulated		Net Book
	Useful Lives	Value		Amortization		Value
Internally developed patents	6–20 years	$	1,030,333	$	(493,188)	$	537,145
Acquired licenses	16–20 years		285,000		(285,000)		—
Total intangible assets subject to amortization			1,315,333		(778,188)		537,145
IPR&D assets	Indefinite		12,418,967		—		12,418,967
Total		$	13,734,300	$	(778,188)	$	12,956,112

	December 31, 2020
		Gross
	Estimated	Carrying		Accumulated		Net Book
	Useful Lives	Value		Amortization		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 was $6,640 and $12,025 for the three months ended June 30, 2021 and 2020, respectively, and $13,280 and $25,876 for the six months ended June 30, 2021 and 2020, respectively. As of June 30, 2021, the weighted average amortization period remaining for intangible assets was 12.2 years. Amortization expense was classified as research and development expenses in the accompanying unaudited consolidated statements of operations and comprehensive loss.