NATURE OF OPERATIONS AND LIQUIDITY - Additional Information (Details) - USD ($)	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Nature Of Operations And Liquidity Disclosure [Abstract]
Accumulated deficit	$ 313,394,750		$ 284,795,447
Net cash used in operating activities	19,768,833	$ 26,663,142
Cash, cash equivalents, restricted cash and marketable securities	$ 65,700,000

The cumulative amount of the reporting entity's undistributed earnings or deficit.

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