Income Taxes (Tables)

12 Months Ended

Dec. 31, 2014

Significant Component of Deferred Tax Assets

Significant components of the Company’s deferred tax assets at December 31, 2014 and 2013 are as follows:

	December 31,
(in thousands)	2014			2013
Net operating loss carryforwards	$	79,050		$	66,209
Start-up and organizational costs		38,562			41,529
Research and development credit carryforwards		26,112			25,058
Stock compensation		1,181			1,028
Capitalized acquisition costs		11,376			12,323
Deferred revenue		534			1,074
Depreciation		208			129
Other		1,547			1,254
		158,570			148,604
Less valuation allowance		(158,570	)		(148,604	)
Net deferred tax assets	$	—		$	—

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)	2014			2013			2012
Federal income tax at statutory rates		34	%		34	%		34	%
State income tax, net of federal tax benefit		2	%		4	%		5	%
Research and development credits		3	%		9	%		10	%
Stock compensation		-4	%		-2	%		-1	%
Uncertain tax position adjustment		0	%		0	%		0	%
Federal R&D tax grant		0	%		0	%		0	%
Other		-4	%		1	%		2	%
Increase in valuation allowance		-31	%		-46	%		-49	%
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, 2014, 2013, and 2012 are as follows:

(in thousands)
Balance at December 31, 2011	$	275
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		—
Decreases for lapses of statute of limitations		—
Balance at December 31, 2012	$	275
Increase/Decrease for tax positions related to the current year		—
Increase/Decrease for tax positions related to prior years		(37	)
Decreases for settlements with applicable taxing authorities		—
Decreases for lapses of statute of limitations		—
Balance at December 31, 2013	$	238
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		—
Decreases for lapses of statute of limitations		—
Balance at December 31, 2014	$	238