Income Taxes (Tables)

12 Months Ended

Dec. 31, 2014

Schedule of effective income tax rate reconciliation

The reconciliation of the income tax benefit computed at the Federal statutory rates to our recorded tax benefit for the years ended December 31, 2014, 2013, and 2012 is as follows:

(in thousands)	December 31,
	2014			2013			2012
Income tax benefit, statutory rates	$	14,980		$	15,373		$	12,687
State taxes on income, net of Federal benefit		2,871			2,922			2,288
Research and development tax credit		1,472			517			332
Employee related		(2,131	)		(766	)		(988	)
Warrant valuation related		1,289			259			189
Income tax benefit		18,481			18,305			14,508
Valuation allowance		(18,481	)		(18,305	)		(14,508	)
Income tax benefit	$	–		$	–		$	–

Schedule of deferred tax assets and liabilities

The tax effects of temporary differences that give rise to deferred tax assets and deferred tax liabilities, at December 31, 2014 and 2013, are as follows:

(in thousands)	December 31,
	2014			2013
Long-term deferred tax assets:
Net operating loss carryforwards (Federal and state)	$	191,643		$	175,258
Research and development tax credits		12,927			10,604
Compensation expense on stock		2,588			3,276
Charitable contribution carryforward		7			7
Inventory reserve		907			198
Deferred revenue		16			53
Other accrued		1,088			1,024
Depreciation		2,630			2,714
Capitalized research and development		1,123			1,326
Total long-term deferred tax assets		212,929			194,460
Less: valuation allowance		(212,929	)		(194,460	)
Deferred tax assets, net of valuation allowance	$	–		$	–