Intangible Assets

3 Months Ended

Mar. 31, 2021

Goodwill And Intangible Assets Disclosure [Abstract]

Intangible Assets

5. Intangible Assets

The Company’s intangible assets consisted of the following:

	March 31, 2021
	Estimated Useful Lives	Gross Carrying Value		Accumulated Amortization			Net Book Value
Internally developed patents	6-20 years	$	946,828	$	(486,548	)	$	460,280
Acquired licenses	16-20 years		285,000		(285,000	)		—
Total intangible assets subject to amortization			1,231,828		(771,548	)		460,280
IPR&D assets	Indefinite		12,418,967		—			12,418,967
Total		$	13,650,795	$	(771,548	)	$	12,879,247

	December 31, 2020
	Estimated Useful Lives	Gross Carrying Value		Accumulated Amortization			Net Book 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 $13,851 for the three months ended March 31, 2021 and 2020, respectively. As of March 31, 2021, the weighted average amortization period remaining for intangible assets was 12.3 years. Amortization expense was classified as research and development expenses in the accompanying unaudited consolidated statements of operations and comprehensive loss.