Income Taxes (Tables)

12 Months Ended

Dec. 31, 2012

Schedule of Effective Income Tax Rate Reconciliation

Income tax benefit for the years ended December 31, 2012 and 2011 differed from amounts computed by applying the applicable U.S. federal corporate income tax rate of 34% to loss before income taxes as a result of the following:


	2012			2011

Computed statutory income tax benefit	$	(27,837	)	$	(28,995	)
(Increase) reduction in income tax benefit resulting from State income tax benefit, net of federal income taxes		(3,711	)		(3,893	)
Nondeductible stock based compensation		333			203
Contribution of services by shareholder		527			71
Research and development tax credits		—			(2,515	)
Other, net		(238	)		477


		(30,926	)		(34,652	)
Change in valuation allowance for deferred tax assets		30,926			34,652

Total income tax provision	$	—		$	—

Schedule of Deferred Tax Assets and Liabilities

The tax effects of temporary differences that comprise the deferred tax assets and liabilities at December 31 are as follows:


	2012		2011


Deferred tax assets
Equity securities	$	4,346	$	1,098
Accrued liabilities		1,910		915
Stock-based compensation		363		178
Deferred revenue		22,684		6,546
Research and development tax credits		5,848		5,556
Net operating loss carryforwards		80,159		70,679

Total deferred tax assets		115,310		84,972
Less: Valuation allowance		113,051		82,125

Net deferred tax assets		2,259		2,847


Deferred tax liabilities
Property and equipment		478		406
Intangible assets		1,781		2,441

Total deferred tax liabilities		2,259		2,847

Net deferred tax assets (liabilities)	$	—	$	—

Summary of Valuation Allowance

Activity within the valuation allowance for deferred tax assets during the years ended December 31, 2012 and 2011 was as follows:


	2012		2011

Valuation allowance at beginning of year	$	82,125	$	52,036

(Decrease) increase in valuation allowance as a result of
Mergers and acquisitions, net		—		(4,563	)
Current year operations		30,926		34,652

Valuation allowance at end of year	$	113,051	$	82,125