SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)

6 Months Ended

Jun. 30, 2018

Accounting Policies [Abstract]

Schedule of number of anti-dilutive shares excluded from the calculation of diluted net loss per share attributable to common stockholders

The following table presents the number of shares excluded from the calculation of diluted net loss per share attributable to common stockholders for the periods below:

	Six Months Ended June 30,
	2017	2018
Common stock warrants	4,491,568	3,391,100
Common stock options	822,305	1,129,653
Non-vested restricted stock unit awards	1,404,392	2,162,547
Total shares excluded from net loss per share attributable to common stockholders	6,718,265	6,683,300