Income Taxes (Tables)

12 Months Ended

Dec. 31, 2019

Income Tax Disclosure [Abstract]

Significant Component of Deferred Tax Assets

Significant components of the Company’s deferred tax assets at December 31, 2019 and 2018 are as follows:

	December 31,
(in thousands)	2019			2018
Deferred tax assets:
Net operating loss carryforwards	$	124,115		$	106,430
Start-up and organizational costs		30,480			33,977
Research and development credit carryforwards		35,130			33,684
Stock compensation		1,087			990
Capitalized acquisition costs		4,501			5,160
Lease liability		626			—
Depreciation		176			132
Other		1,186			920
		197,301			181,293
Less valuation allowance		(196,696	)		(181,293	)
Total deferred tax assets		605			—
Deferred tax liabilities:
Right of use asset		(605	)		—
Total deferred tax liabilities	$	(605	)	$	—
Net deferred taxes	$	—		$	—

Reconciliation of Income Tax Expense (Benefit)

A reconciliation of income tax expense (benefit) at the statutory federal income tax rate and income taxes as reflected in the financial statements is as follows:

	Year Ended December 31,
(in thousands)	2019			2018			2017
Federal income tax at statutory rates		21	%		21	%		34	%
State income tax, net of federal tax benefit		3	%		4	%		4	%
Non-cash inducement warrant expense		-11	%		0	%		0	%
Research and development credits		1	%		2	%		3	%
Stock compensation		0	%		-1	%		-1	%
Research and development true-up		0	%		0	%		-7	%
Officers compensation		0	%		-1	%		-2	%
Other		-1	%		-2	%		-3	%
Federal rate change		0	%		3	%		-124	%
Change in valuation allowance		-13	%		-26	%		96	%
Effective tax rate		0	%		0	%		0	%