Income Taxes (Tables)

12 Months Ended

Dec. 31, 2018

Income Tax Disclosure [Abstract]

Schedule of Provision (Benefit) for Federal Income Taxes

The provision (benefit) for federal income taxes in 2018 and 2017 is as follows (in thousands):

	December 31,
	2018		2017
Current
Federal	$	—	$	(247	)
State		—		—
		—		(247	)
Deferred
Federal	$	—	$	—
State		—		—
Total deferred tax expense		—		—
Total income tax expense	$	—	$	(247	)

Schedule of Income (Loss) Before Income Taxes Attributed to Geographic Locations

	December 31,
	2018			2017
United States	$	(76,256	)	$	(125,093	)
Foreign		(77	)		39,867
Net loss before provision for income taxes	$	(76,333	)	$	(85,226	)

Summary of Statutory Federal Tax Rate to Income or Loss before Taxes

Income tax expense (benefit) in 2018 and 2017 differed from the amount expected by applying the statutory federal tax rate to the income or loss before taxes as summarized below:

	December 31,
	2018			2017
Federal tax benefit at statutory rate		21	%		34	%
Change in valuation allowance		99	%		(7	)%
Research and development credits		—			16	%
Section 382 limitation		(109	)%		—
Other non-deductible expenses		(11	)%		(3	)%
Change in rate differential		—			(38	)%
Build-to-suit adjustments		—			(2	)%
Total		0	%		0	%

Significant Components of Net Deferred Tax Assets

Significant components of the Company’s net deferred tax assets at December 31, 2018 and 2017 are as follows (in thousands):

	December 31,
	2018			2017
Net operating loss carry forwards	$	2,335		$	69,281
Research and development tax credits		168			34,891
Stock based compensation and other		8,567			5,693
Total deferred tax assets		11,070			109,865
Less: Valuation allowance		(10,336	)		(108,782	)
Deferred tax liabilities		(734	)		(1,083	)
Net deferred tax assets	$	—		$	—

Reconciliation of Amount of Unrecognized Tax Benefits

A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands):

	Amount
Balance at January 1, 2017	$	10,116
Gross increase/ (decrease) related to prior year tax positions1		(7,776	)
Gross increase related to current year positions		1,594
Reductions to unrecognized tax benefits related to lapsing statute of limitations		—
Balance at December 31, 2017	$	3,934
Gross increase/ (decrease) related to prior year tax positions		(3,934	)
Gross increase related to current year positions		72
Reductions to unrecognized tax benefits related to lapsing statute of limitations		—
Balance at December 31, 2018	$	72

¹ During 2017, the Company received new information related to its Orphan Drug Credit which provides clarification regarding tax positions previously taken. As a result of this new information, Management re-assessed its Orphan Drug Credit uncertain tax position and made its best estimate to account for the higher level of certainty. The change in unrecognized tax benefit is fully offset by a corresponding change in valuation allowance and therefore has no impact on the income statement.