Income Taxes (Tables)

12 Months Ended

Dec. 31, 2014

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

A reconciliation of the expected income tax benefit (expense) computed using the federal statutory income tax rate to the Company’s effective income tax rate is as follows for the years ended December 31, 2012, 2013, and 2014:


	December 31,
	2012			2013			2014
Income tax computed at federal statutory tax rate		34.0	%		34.0	%		34.0	%
State taxes, net of federal benefit		3.9	%		4.2	%		6.3	%
State taxes rate change, net of federal benefit		—			—			30.4	%
International operations		(0.2	)%		(2.1	)%		6.6	%
Research and development credits		2.4	%		13.8	%		(22.6	)%
Orphan drug credits		—			6.6	%		(57.4	)%
Equity compensation		(2.2	)%		(2.5	)%		16.6	%
Other		(0.2	)%		(1.3	)%		(2.1	)%
Change in valuation allowance		(37.7	)%		(52.7	)%		(11.8	)%
Total		0.0	%		0.0	%		0.0	%

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

Net deferred tax assets and liabilities are comprised of the following:

	December 31,
	2013			2014
Deferred tax assets
Net operating loss carryforwards	$	65,678,000		$	71,074,000
Research and development credit carryforwards		9,592,000			10,836,000
Orphan Drug Credit		1,495,000			6,286,000
Stock options		2,377,000			4,103,000
Other		120,000			202,000
Deferred tax assets		79,262,000			92,501,000
Deferred tax liabilities
Deferred revenue		(2,594,000	)		(16,408,000	)
Property and equipment		(241,000	)		(316,000	)
Deferred tax liabilities	$	(2,835,000	)	$	(16,724,000	)
Net deferred tax asset before valuation allowance	$	76,427,000		$	75,777,000
Less valuation allowance		(76,427,000	)		(75,777,000	)
Net deferred tax assets	$	—		$	—