Net Loss per Share (Tables)

12 Months Ended

Dec. 31, 2016

Basic and Diluted Net Loss per Share Attributable to Common Stockholders

Basic and diluted net loss per share attributable to common stockholders was calculated as follows:

	Year Ended December 31,
	2016			2015			2014
Numerator:
Net loss	$	(91,579	)	$	(54,780	)	$	(16,709	)
Accretion of convertible preferred stock to redemption value		—			—			(1,291	)
Net loss attributable to common stockholders	$	(91,579	)	$	(54,780	)	$	(18,000	)
Denominator:
Weighted average common shares outstanding, basic and diluted		39,846,928			23,532,400			6,748,037
Net loss per share attributable to common stockholders, basic and diluted	$	(2.30	)	$	(2.33	)	$	(2.67	)

Summary of Potential Common Shares Excluded from Calculation of Diluted Net Loss per Share

The following potential common shares, presented based on amounts outstanding at each period end, were excluded from the calculation of diluted net loss per share attributable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect:

	Year Ended December 31,
	2016		2015		2014
Stock options to purchase common stock		5,069,133		5,026,246		3,579,342
Unvested restricted stock units		115,500		—		—
Unvested restricted common stock		—		—		52,500
Warrants for the purchase of convertible preferred stock		—		—		92,127
Warrants for the purchase of common stock		—		—		738,635
Convertible preferred stock (as converted to common stock)		—		—		21,478,098
		5,184,633		5,026,246		25,940,702