| Schedule of reconciliation of income taxes computed using the U.S. federal statutory rate to that reflected in operations |
A reconciliation of income taxes computed using the U.S. federal statutory rate to that reflected in operations follows (in thousands):
|
|
|
Year Ended December 31,
|
|
|
|
|
2014
|
|
2013
|
|
2012
|
|
|
Income tax benefit using U.S. federal statutory rate
|
|
$
|
(21,243
|
)
|
$
|
(20,635
|
)
|
$
|
(23,504
|
)
|
|
State income taxes, net of federal benefit
|
|
|
(2,494
|
)
|
|
(2,255
|
)
|
|
(2,774
|
)
|
|
Stock-based compensation
|
|
|
149
|
|
|
92
|
|
|
72
|
|
|
Research and development tax credits
|
|
|
(499
|
)
|
|
(1,277
|
)
|
|
(55
|
)
|
|
Change in the valuation allowance
|
|
|
23,186
|
|
|
27,194
|
|
|
25,175
|
|
|
Permanent items
|
|
|
910
|
|
|
(3,085
|
)
|
|
709
|
|
|
Other
|
|
|
(9
|
)
|
|
(34
|
)
|
|
377
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
$
|
—
|
|
$
|
—
|
|
$
|
—
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Schedule of principal components of the Company's deferred tax assets |
The principal components of the Company's deferred tax assets are as follows (in thousands):
|
|
|
December 31,
|
|
|
|
|
2014
|
|
2013
|
|
|
Current assets:
|
|
|
|
|
|
|
|
|
Accrued expenses
|
|
$
|
671
|
|
$
|
351
|
|
|
Deferred rent
|
|
|
—
|
|
|
9
|
|
|
|
|
|
|
|
|
|
|
|
Gross current deferred tax assets
|
|
|
671
|
|
|
360
|
|
|
|
|
|
|
|
|
|
|
|
Valuation allowance
|
|
|
(671
|
)
|
|
(360
|
)
|
|
|
|
|
|
|
|
|
|
|
Net current deferred tax assets
|
|
$
|
—
|
|
$
|
—
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Non-current assets:
|
|
|
|
|
|
|
|
|
Net operating loss carryforwards
|
|
$
|
121,278
|
|
$
|
100,284
|
|
|
Capitalized research and development
|
|
|
356
|
|
|
662
|
|
|
Research and development credits
|
|
|
4,844
|
|
|
4,345
|
|
|
Depreciation and amortization
|
|
|
(47
|
)
|
|
110
|
|
|
Other
|
|
|
3,158
|
|
|
1,313
|
|
|
|
|
|
|
|
|
|
|
|
Gross non-current deferred tax assets
|
|
|
129,589
|
|
|
106,714
|
|
|
Valuation allowance
|
|
|
(129,589
|
)
|
|
(106,714
|
)
|
|
|
|
|
|
|
|
|
|
|
Net non-current deferred tax assets
|
|
$
|
—
|
|
$
|
—
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|