Entity information:
M.
Income Taxes
 
The Company
’s financial statements include a total state tax benefit related to research and development credits of
$43,000,
$15,000
and
$15,000
on a loss before income taxes of
$43.4
million,
$16.5
million and
$54.6
million for the years ended
December 31, 2017,
2016
and
2015,
respectively. A reconciliation of the difference between the benefit for income taxes and income taxes at the statutory U.S. federal income tax rate is as follows (in thousands):
 
   
Year ended December 31,
   
2017
 
2016
 
2015
Federal statutory rate
   
34.00
%
   
34.00
%
   
34.00
%
Effect of:
                       
Change in valuation allowance
   
13.38
 
   
(69.31
)
   
(19.25
)
Return to provision and deferred true-up    
2.18
     
(23.83
)    
 
Change in rate    
(49.06
)    
(14.63
)    
 
State tax benefit (net of federal)
   
2.71
     
15.64
     
4.06
 
Warrant liability
   
(2.42
)
   
68.44
 
   
(15.28
State research and development credit
   
0.10
     
0.09
     
0.03
 
Federal research and development credit
   
1.50
     
5.65
     
0.84
 
Amortization    
(1.22
)    
(3.15
)    
 
Conversion feature and put option on convertible
notes
   
 
   
 
   
(1.68
)
Stock-based compensation
   
(1.03
)
   
(12.71
   
(1.28
)
Other
   
(0.04
)
   
(0.10
   
(1.49
)
Federal income tax benefit (provision) effective rate
   
0.10
%
   
0.09
%
   
(0.05
)%
 
The components of deferred tax assets and liabilities are as follows (in thousands):
 
   
December 31,
   
2017
 
2016
 
2015
Deferred tax assets relating to:
                       
Net operating loss carryforwards
  $
37,028
    $
44,984
    $
26,617
 
Research and development tax carryforward
   
3,788
     
3,166
     
2,254
 
Other deferred tax assets
   
2,409
     
715
     
232
 
Total gross deferred tax assets
   
43,225
     
48,865
     
29,103
 
Deferred tax liabilities relating to:
                       
Property and equipment
   
260
     
89
     
80
 
Total gross
deferred tax liabilities
   
260
     
89
     
80
 
Deferred tax assets less liabilities
   
42,965
     
48,776
     
29,023
 
Valuation allowance
   
(42,965
)
   
(48,776
)
   
(29,023
)
Net deferred tax asset (liability)
  $
    $
    $
 
 
H.R.
1,
“An Act to provide for reconciliation pursuant to titles II and V of the concurrent resolution on the budget for fiscal year
2018”
(the
"2017
Tax Act") was signed into law on
December 22, 2017.
The
2017
Tax Act significantly revises the U.S. corporate income tax by, among other things, lowering the statutory corporate tax rate from
 
35%
 to 
21%,
eliminating certain deductions, imposing a mandatory
one
-time tax on accumulated earnings of foreign subsidiaries, introducing new tax regimes, and changing how foreign earnings are subject to U.S. tax. The
2017
Tax Act also enhanced and extended through
2026
the option to claim accelerated depreciation deductions on qualified property. 
 
Also on
December 22, 2017,
the SEC staff issued Staff Accounting Bulletin
No.
118
(“SAB
118”
), which provides guidance on accounting for the tax effects of the
2017
Tax Act. SAB
118
provides a measurement period that should
not
extend beyond
one
year from the 
2017
Tax Act enactment date for companies to complete the accounting under ASC
740,
Income Taxes. As of
December 31, 2017,
the Company has
not
completed its accounting related to the enactment of the
2017
Tax Act.
 However, the Company has made reasonable estimates of the effects on its income tax provision with respect to certain items, primarily the revaluation of its existing U.S. deferred tax balances as described above.
 
In assessing the realizability of deferred tax assets, management considers whether it is more likely than
not
that some portion or all of the deferred tax assets will
not
be realized. The ultimate realization of deferred tax
assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. Management considers the scheduled reversal of deferred tax liabilities, projected future taxable income and tax planning strategies in making this assessment. Based upon the level of historical taxable income and projections for future taxable income over the periods in which the deferred tax assets are deductible, management believes it is more likely than
not
that the Company will
not
realize the benefits of these deductible differences in the future.
 
The Company had the following federal net operating loss carryforward and research activities credits as of
December 31, 2017 (
in thousands):
 
   
Net Operating
 
Research
 
 
 
 
Year Incurred
 
Loss Carryforwards
 
Activities Credit
 
Expiration
2007
  $
454
 
  $
30
 
   
2027
 
2008
   
1,178
 
   
65
 
   
2028
 
2009
   
3,060
 
   
176
 
   
2029
 
2010
   
3,423
 
   
149
 
   
2030
 
2011
   
9,929
 
   
176
 
   
2031
 
2012
   
 
   
170
 
   
2032
 
2013
   
4,353
 
   
133
 
   
2033
 
2014
   
16,265
 
   
894
 
   
2034
 
2015
   
24,126
 
   
598
 
   
2035
 
2016    
 40,715
 
   
745
 
   
 2036
 
2017    
33,828
 
   
652
 
   
2037
 
    $
137,331
 
  $
3,788
 
   
 
 
 
The Company also has certain state net operating loss carryforwards totaling
$134.6
million that expire between
2027
and
2037.
Due to potential ownership changes that
may
have occurred or would occur in the future, Internal Revenue Code Section
382
may
place additional l
imitations on the Company’s ability to utilize the net operating loss carryforward.
 
ASC
740
-
10,
Accounting for Uncertainty in Income Taxes
, uses the term “more likely than
not”
to evaluate whether or
not
a tax position will be sustained upon examination. The Company has
not
identified any tax positions that do
not
meet the more likely than
not
threshold.