Condensed Consolidated Statements of Operations (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Operating expenses:
Research and development	$ 16,182	$ 17,583
General and administrative	4,150us-gaap_GeneralAndAdministrativeExpense	5,324us-gaap_GeneralAndAdministrativeExpense
Total operating expenses	20,332us-gaap_OperatingExpenses	22,907us-gaap_OperatingExpenses
Loss from operations	(20,332)us-gaap_OperatingIncomeLoss	(22,907)us-gaap_OperatingIncomeLoss
Interest expense, net	(375)	(650)
Net loss	$ (20,707)	$ (23,557)
Net loss per common share:
Basic and diluted net loss per common share (in dollars per share)	$ (0.19)us-gaap_EarningsPerShareBasicAndDiluted	$ (0.28)us-gaap_EarningsPerShareBasicAndDiluted
Basic and diluted weighted average number of common shares outstanding	108,376,264	85,438,127

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The amount of net income or loss for the period per each share in instances when basic and diluted earnings per share are the same amount and reported as a single line item on the face of the financial statements. Basic earnings per share is the amount of net income or loss for the period per each share of common stock or unit outstanding during the reporting period. Diluted earnings per share includes the amount of net income or loss for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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- Definition

The aggregate total of expenses of managing and administering the affairs of an entity, including affiliates of the reporting entity, which are not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.4)

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The net amount of nonoperating interest income (expense).

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Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 260

-SubTopic 10

-Section 45

-Paragraph 11

-URI http://asc.fasb.org/extlink&oid=7655603&loc=d3e1377-109256

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Generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Includes selling, general and administrative expense.

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The net result for the period of deducting operating expenses from operating revenues.

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- Definition

The costs incurred in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, excluding in-process research and development acquired in a business combination consummated during the period. Excludes software research and development, which has a separate concept.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 730

-SubTopic 10

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6420194&loc=d3e21568-108373

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-Publisher FASB

-Name Accounting Standards Codification

-Glossary Research and Development

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Average number of shares or units issued and outstanding that are used in calculating basic and diluted earnings per share (EPS).

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