Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

Income Tax Disclosure [Abstract]

Significant Component of Deferred Tax Assets

Significant components of the Company’s deferred tax assets at December 31, 2017 and 2016 are as follows:

	December 31,
(in thousands)	2017			2016
Net operating loss carryforwards	$	89,098		$	100,790
Start-up and organizational costs		37,488			59,360
Research and development credit carryforwards		32,395			34,845
Stock compensation		1,330			2,014
Capitalized acquisition costs		5,822			9,389
Deferred revenue		11,126			18,636
Depreciation		136			227
Other		993			1,537
		178,388			226,798
Less valuation allowance		(178,388	)		(226,798	)
Effective tax rate	$	—		$	—

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)	2017			2016			2015
Federal income tax at statutory rates		34	%		34	%		34	%
State income tax, net of federal tax benefit		4	%		1	%		5	%
Research and development credits		3	%		3	%		3	%
Stock compensation		-1	%		-1	%		-1	%
Channel rights		0	%		-25	%		0	%
Research and development true-up		-7	%		0	%		0	%
Officers compensation		-2	%		0	%		0	%
Other		-3	%		0	%		0	%
Federal rate change		-124	%		0	%		0	%
Increase in valuation allowance		96	%		-12	%		-41	%
Effective tax rate		0	%		0	%		0	%

Summary of Adjustments to Uncertain Tax Position

A summary of the company’s adjustments to its uncertain tax positions in the years ended December 31, 2017, 2016, and 2015 are as follows:

(in thousands)
Balance at December 31, 2014	$	238
Increase/Decrease for tax positions related to the current year		—
Increase/Decrease for tax positions related to prior years		—
Decrease for settlements with applicable taxing authorities		—
Decrease for previous year’s lapses of statute of limitations		(20	)
Decrease for impact of §382 limitations		(218	)
Decrease for lapses of statute of limitations		—
Balance at December 31, 2015	$	—
Increase/Decrease for tax positions related to the current year		—
Increase/Decrease for tax positions related to prior years		—
Decreases for settlements with applicable taxing authorities		—
Decrease for lapses of statute of limitations		—
Balance at December 31, 2016	$	—
Increase/Decrease for tax positions related to the current year		—
Increase/Decrease for tax positions related to prior years		—
Decrease for settlements with applicable taxing authorities		—
Decrease for lapses of statute of limitations		—
Balance at December 31, 2017	$	—