Loss per Common Share

6 Months Ended

Jun. 30, 2018

Loss per Common Share

Loss per Common Share

4. Loss per Common Share

The following table presents the computations of basic and dilutive net loss per share:

	Three months ended June 30,				Six months ended June 30,
	June 30,				June 30,
		2018		2017		2018		2017
Loss attributable to common shareholders — basic and diluted	$	(13,060)	$	(21,121)	$	(31,712)	$	(44,199)
Weighted-average number of common shares used in net loss per share - basic and diluted		32,967,718		29,441,514		32,935,873		29,396,143
Loss per share - basic and diluted	$	(0.40)	$	(0.72)	$	(0.96)	$	(1.50)

The following potentially dilutive securities, which represent all outstanding potentially dilutive securities, were excluded from the calculation of diluted net loss per share due to their anti-dilutive effect (in common stock equivalent shares):

	Three months ended June 30,		Six months ended June 30,
	2018	2017	2018	2017
Outstanding stock options	3,665,459	3,124,039	3,665,459	3,124,039
Warrants	—	2,445	—	2,445
Unvested restricted stock (1)	12,072	57,228	12,072	57,228
Restricted stock units	522,190	223,194	522,190	223,194
(1) - Includes shares of unvested restricted stock remaining from the early exercise of stock options.