SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)

3 Months Ended

Mar. 31, 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:

	Three Months Ended March 31,
	2017	2018
Common stock warrants	4,491,568	3,465,256
Common stock options	904,798	1,080,152
Non-vested restricted stock unit awards	1,401,903	1,555,769
Total shares excluded from net loss per share attributable to common stockholders	6,798,269	6,101,177