STOCK-BASED COMPENSATION (Tables)
   | 
9 Months Ended | 
Sep. 30, 2020  | 
| DESCRIPTION OF BUSINESS | 
 
 | 
| Schedule of Equity incentive plan | 
   | 
   | 
 Awards  
Reserved for Issuance 
 | 
   | 
   | 
 Awards  
Outstanding 
 | 
   | 
   | 
 Awards  
Available  
for Grant 
 | 
   | 
 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 
2016 Equity incentive plan  | 
   | 
   | 
2,000,000 | 
   | 
   | 
   | 
544,397 | 
   | 
   | 
   | 
1,455,603 | 
   | 
 
2018 Equity incentive plan  | 
   | 
   | 
43,976,425 | 
   | 
   | 
   | 
15,055,708 | 
   | 
   | 
   | 
28,920,717 | 
   | 
 
 
 | 
| Schedule of Stock option activity | 
   | 
   | 
Number of Shares   | 
   | 
   | 
Weighted-Average Exercise Price Per Share   | 
   | 
   | 
Weighted-Average Remaining Contractual Life   | 
   | 
Aggregate Intrinsic Value of In-the-Money Options   | 
   | 
 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 
Options outstanding as of January 1, 2020  | 
   | 
   | 
12,365,295 | 
   | 
   | 
$ | 
0.46 | 
   | 
   | 
   | 
   | 
   | 
   | 
 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 
Options granted  | 
   | 
   | 
10,559,090 | 
   | 
   | 
$ | 
0.07 | 
   | 
   | 
   | 
   | 
   | 
   | 
 
Options exercised  | 
   | 
   | 
- | 
   | 
   | 
$ | 
- | 
   | 
   | 
   | 
   | 
   | 
   | 
 
Options forfeited  | 
   | 
   | 
(6,566,667 | 
) | 
   | 
$ | 
1.29 | 
   | 
   | 
   | 
   | 
   | 
   | 
 
Options expired  | 
   | 
   | 
(248,048 | 
) | 
   | 
$ | 
1.33 | 
   | 
   | 
   | 
   | 
   | 
   | 
 
Options outstanding as of September 30, 2020  | 
   | 
   | 
16,109,670 | 
   | 
   | 
$ | 
0.46 | 
   | 
   | 
9.0 years  | 
   | 
$ | 
- | 
   | 
 
Options exercisable as of September 30, 2020  | 
   | 
   | 
5,593,814 | 
   | 
   | 
$ | 
0.91 | 
   | 
   | 
8.4 years   | 
   | 
$ | 
- | 
   | 
 
 
 | 
| Schedule of Stock based compensation assumptions | 
   | 
   | 
September 30,  | 
   | 
   | 
September 30,  | 
   | 
 
   | 
   | 
2020  | 
   | 
   | 
2019  | 
   | 
 
Expected term (years)  | 
   | 
6 Years  | 
   | 
   | 
6 Years  | 
   | 
 
Volatility  | 
   | 
   | 
104.2 | 
% | 
   | 
   | 
115.7 | 
% | 
 
Risk-free interest rate  | 
   | 
   | 
0.5 | 
% | 
   | 
   | 
1.9 | 
% | 
 
Dividend yield  | 
   | 
   | 
0 | 
% | 
   | 
   | 
0 | 
% | 
 
 
 | 
| Schedule of Stock-based compensation expense | 
   | 
   | 
(in thousands except for shares / options)  | 
   | 
 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 
   | 
   | 
For the Three Months Ended  | 
   | 
 
   | 
   | 
September 30, 2020  | 
   | 
   | 
September 30, 2019  | 
   | 
 
Type of Award   | 
   | 
Number of Shares or Options Granted  | 
   | 
   | 
Stock-Based Compensation Expense   | 
   | 
   | 
Number of Shares or Options Granted  | 
   | 
   | 
Stock-Based Compensation Expense   | 
   | 
 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 
Stock options  | 
   | 
   | 
909,090 | 
   | 
   | 
$ | 
298 | 
   | 
   | 
   | 
143,848 | 
   | 
   | 
$ | 
1,078 | 
   | 
 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 
Stock grants:  | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 
Employees (common stock)  | 
   | 
   | 
- | 
   | 
   | 
   | 
- | 
   | 
   | 
   | 
91,465 | 
   | 
   | 
   | 
38 | 
   | 
 
Directors (common stock)  | 
   | 
   | 
1,082,700 | 
   | 
   | 
   | 
119 | 
   | 
   | 
   | 
173,610 | 
   | 
   | 
   | 
102 | 
   | 
 
Non–employee consultants (common stock)  | 
   | 
   | 
84,615 | 
   | 
   | 
   | 
11 | 
   | 
   | 
   | 
0 | 
   | 
   | 
   | 
0 | 
   | 
 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 
Total stock–based compensation expense  | 
   | 
   | 
   | 
   | 
   | 
$ | 
428 | 
   | 
   | 
   | 
   | 
   | 
   | 
$ | 
1,218 | 
   | 
 
 
    
   | 
   | 
For the Nine Months Ended  | 
   | 
 
   | 
   | 
September 30, 2020  | 
   | 
   | 
September 30, 2019  | 
   | 
 
Type of Award   | 
   | 
Number of Shares or Options Granted  | 
   | 
   | 
Stock-Based Compensation Expense   | 
   | 
   | 
Number of Shares or Options Granted  | 
   | 
   | 
Stock-Based Compensation Expense   | 
   | 
 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 
Stock options  | 
   | 
   | 
10,559,090 | 
   | 
   | 
$ | 
1,536 | 
   | 
   | 
   | 
4,144,666 | 
   | 
   | 
$ | 
3,314 | 
   | 
 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 
Stock grants:  | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 
Employees (common stock)  | 
   | 
   | 
3,179,544 | 
   | 
   | 
   | 
58 | 
(a) | 
   | 
   | 
564,799 | 
   | 
   | 
   | 
428 | 
   | 
 
Directors (common stock)  | 
   | 
   | 
909,090 | 
   | 
   | 
   | 
19 | 
(b) | 
   | 
   | 
173,610 | 
   | 
   | 
   | 
102 | 
   | 
 
Non–employee consultants (common stock)  | 
   | 
   | 
1,159,615 | 
   | 
   | 
   | 
59 | 
   | 
   | 
   | 
66,376 | 
   | 
   | 
   | 
59 | 
   | 
 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 
Total stock–based compensation expense  | 
   | 
   | 
   | 
   | 
   | 
$ | 
1,672 | 
   | 
   | 
   | 
   | 
   | 
   | 
$ | 
3,904 | 
   | 
 
 
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