LOSS PER COMMON SHARE (Tables)

9 Months Ended

Sep. 30, 2017

LOSS PER COMMON SHARE

Schedule of computations of basic and diluted net loss per share

	Three months ended September 30,				Nine months ended September 30,
		2017		2016		2017		2016
Loss attributable to common shareholders — basic and diluted	$	(13,263)	$	(26,444)	$	(57,462)	$	(66,617)
Weighted-average number of common shares used in net loss per share - basic and diluted		29,753,043		23,460,340		29,517,396		23,334,558
Loss per share - basic and diluted	$	(0.45)	$	(1.13)	$	(1.95)	$	(2.85)

Schedule of potentially dilutive securities excluded from computations of diluted weighted-average shares outstanding

	Three months ended September 30,		Nine months ended September 30,
	2017	2016	2017	2016
Outstanding stock options	3,056,954	2,258,775	3,056,954	2,258,775
Warrants	2,445	2,445	2,445	2,445
Unvested restricted stock(1)	44,586	95,159	44,586	95,159
Restricted stock units	218,872	41,739	218,872	41,739
(1) - Includes shares of unvested restricted stock remaining from the early exercise of stock options.