Net Loss per Share (Tables)

12 Months Ended

Dec. 31, 2015

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,
	2015			2014			2013
Numerator:
Net loss	$	(54,780	)	$	(16,709	)	$	(6,102	)
Accretion of convertible preferred stock to redemption value		-			(1,291	)		(875	)
Net loss attributable to common stockholders	$	(54,780	)	$	(18,000	)	$	(6,977	)
Denominator:
Weighted average common shares outstanding, basic and diluted		23,532,400			6,748,037			6,394,916
Net loss per share attributable to common stockholders, basic and diluted	$	(2.33	)	$	(2.67	)	$	(1.09	)

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,
	2015		2014		2013
Stock options to purchase common stock		5,026,246		3,579,342		1,261,836
Unvested restricted common stock		—		52,500		198,750
Warrants for the purchase of convertible preferred stock		—		92,127		92,127
Warrants for the purchase of common stock		—		738,635		—
Convertible preferred stock (as converted to common stock)		—		21,478,098		10,478,189
		5,026,246		25,940,702		12,030,902