Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

Income Taxes

Schedule of domestic and foreign components of net loss

The following table presents domestic and foreign components of net loss for the periods presented (in thousands):

	Year Ended December 31,
	2017		2016		2015
Domestic	$	(34,556)	$	(34,977)	$	(10,483)
Foreign		(2,401)		(2,200)		(4,375)
Total net loss	$	(36,957)	$	(37,177)	$	(14,858)

Schedule of provision differences from federal statutory rate

	Year Ended December 31,
	2017		2016		2015
Federal statutory income tax rate	34.0	%	34.0	%	34.0	%
State taxes, net of federal benefit	0.5		6.5		(2.7)
Warrant revaluation	—		(4.3)		(0.2)
Research credit	2.6		1.8		1.1
Foreign tax rate difference	(1.2)		(1.6)		(11.8)
Change in tax law	(31.2)		—		—
Change in valuation allowance	(5.2)		(36.0)		(19.9)
Other	0.5		(0.4)		(0.5)
Provision for income taxes	—	%	—	%	—	%

Schedule of components of deferred tax assets

The components of the deferred tax assets are as follows (in thousands):

	December 31,
	2017		2016
Deferred tax assets:
Net operating loss carryforwards	$	21,682	$	21,501
Depreciation and amortization		339		419
Accruals/other		1,322		908
Research and development credits and foreign credits		2,544		1,143
Total deferred tax assets		25,887		23,971
Valuation allowance		(25,887)		(23,971)
Net deferred tax assets	$	—	$	—

Schedule of reconciliation of beginning and ending unrecognized tax benefits

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

	Year Ended December 31,
	2017		2016		2015
Balance at beginning of year	$	2,131	$	805	$	—
Additions based on tax positions related to prior years		—		707		690
Additions based on tax positions related to current year		3,283		619		115
Balance at end of year	$	5,414	$	2,131	$	805