Income Taxes (Tables)

12 Months Ended

Dec. 31, 2020

The principal components of the Company’s deferred tax assets and liabilities are as follows:


	December 31,
	2020			2019
Deferred tax assets:
Net operating loss carryovers	$	65,989,759		$	56,646,542
Share-based compensation		2,265,006			1,770,295
R&D tax credits		3,833,265			3,149,249
Accrued compensation and severance		587,183			454,128
Lease liability		1,012,743			1,101,248
Intangible assets		98,915			110,178

Total deferred tax assets	$	73,786,871		$	63,231,640
Valuation allowance		(72,803,194	)		(62,136,614	)

Total deferred tax assets net of valuation allowance	$	983,677		$	1,095,026
Deferred tax liabilities:
Right-of-use asset		(832,477	)		(909,271	)
Depreciation		(151,200	)		(185,755	)

Total deferred tax liabilities	$	(983,677	)	$	(1,095,026	)

Net deferred tax asset (liability)	$	—		$	—

A reconciliation of the statutory U.S. Federal rate to the company’s effective tax rate is as follows:


	Year Ended December 31,
	2020			2019			2018
Federal income tax benefit at s t atutory rate		(21.00	)%		(21.00	)%		(21.00	)%
State income tax, net of federal benefit		(9.09	)		(15.09	)		(5.64	)
Permanent items including change in fair value of warrants		(5.35	)		(21.87	)		4.80
Change in valuation allowance		37.88			62.56			23.95
R&D tax credits		(2.43	)		(4.72	)		(2.11	)
Other		(0.01	)		0.12			—

Effective income tax (benefit) expense rate		0	%		0	%		0	%