Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues:
Revenues	$ 21,416	$ 8,253	$ 34,053	$ 11,678
Operating expenses:
Research and development	29,255	14,984	52,802	27,926
General and administrative	11,301	6,037	21,388	13,312
Total operating expenses	40,556	21,021	74,190	41,238
Loss from operations	(19,140)	(12,768)	(40,137)	(29,560)
Interest and other income, net	2,500	277	3,310	437
Net loss	$ (16,640)	$ (12,491)	$ (36,827)	$ (29,123)
Basic and diluted net loss per share	$ (0.17)	$ (0.17)	$ (0.40)	$ (0.41)
Shares used in computing basic and diluted net loss per share	97,267	72,527	91,831	71,780
Collaboration Agreements [Member]
Revenues:
Revenues	$ 21,289	$ 7,977	$ 33,840	$ 11,283
Research Grants [Member]
Revenues:
Revenues	$ 127	$ 276	$ 213	$ 395

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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