Intangible Assets

6 Months Ended

Jun. 30, 2020

Goodwill And Intangible Assets Disclosure [Abstract]

Intangible Assets

5. Intangible Assets

The Company’s intangible assets consisted of the following:

	June 30, 2020
	Estimated Useful Lives	Gross Carrying Value		Accumulated Amortization			Net Book Value
Internally developed patents	6-10 years	$	825,659	$	(466,866	)	$	358,793
Acquired licenses	16-20 years		285,000		(277,105	)		7,895
Total intangible assets subject to amortization			1,110,659		(743,971	)		366,688
IPR&D assets	Indefinite		12,418,967		—			12,418,967
Total		$	13,529,626	$	(743,971	)	$	12,785,655

	December 31, 2019
	Estimated Useful Lives	Gross Carrying Value		Accumulated Amortization			Net Book Value
Internally developed patents	6-10 years	$	746,323	$	(448,874	)	$	297,449
Acquired licenses	16-20 years		285,000		(269,221	)		15,779
Total intangible assets subject to amortization			1,031,323		(718,095	)		313,228
IPR&D assets	Indefinite		12,418,967		—			12,418,967
Total		$	13,450,290	$	(718,095	)	$	12,732,195

Amortization expense of intangible assets was $12,025 and $14,836 for the three months ended June 30, 2020 and 2019, and $25,876 and $107,580 for the six months ended June 30, 2020 and 2019, respectively. Amortization expense was classified as research and development expenses in the accompanying unaudited consolidated statements of operations and comprehensive loss.

As of June 30, 2020, future estimated amortization expense are as follows:

Years ending December 31,
The remainder of 2020	$	20,596
2021		27,687
2022		27,687
2023		27,687
2024		23,781
2025 and thereafter		239,250
Total	$	366,688