Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating expenses
Selling, general and administrative	$ 73,615	$ 44,478	$ 30,635
Research and development	72,078	52,394	44,451
Total operating expenses	145,693	96,872	75,086
Loss from operations	(145,693)	(96,872)	(75,086)
Other income (expense), net	(1,170)	(1,994)	862
Net loss before income taxes	(146,863)	(98,866)	(74,224)
Income tax (benefit) expense	(1,758)	193	139
Net loss	$ (145,105)	$ (99,059)	$ (74,363)
Net loss per common share - basic and diluted (in dollars per share)	$ (4.11)	$ (3.40)	$ (2.88)
Weighted average number of common shares outstanding—basic and diluted (in shares)	35,324,472	29,135,583	25,781,230
Net loss	$ (145,105)	$ (99,059)	$ (74,363)
Unrealized gain (loss) on available-for-sale investments	40	111	(72)
Comprehensive loss	$ (145,065)	$ (98,948)	$ (74,435)

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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