Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities
Net loss	$ (68,345,186)	$ (30,965,464)	$ (28,943,392)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	6,115,160	1,754,974	2,072,210
Amortization of debt discount	649,993	375,635	470,521
Change in fair value of warrants		(2,791,000)	646,000
Depreciation	37,330	48,935	42,557
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	833,265	32,058	102,143
Other assets	(27,530)	75,607	(75,131)
Accounts payable	7,256,080	251,789	(645,717)
Accrued expenses and other current liabilities	7,105,829	1,163,765	(140,843)
Net cash used in operating activities	(46,375,059)	(30,053,701)	(26,471,652)
Cash flows from investing activities
Purchases of equipment	(16,121)	(32,696)	(9,898)
Net cash used in investing activities	(16,121)	(32,696)	(9,898)
Cash flows from financing activities
Payment of debt issuance costs		(25,997)
Procceds from issuance of common stock upon financing, net	238,233,817	12,881,321	23,677,341
Proceeds from issuance of term loan	20,000,000
Repayment of principal on term loan	(7,238,889)	(3,333,333)	(277,778)
Proceeds from issuance of common stock upon exercise of options	1,143,841	380,322	316,719
Proceeds issuance of common stock upon exercise of warrants	249,836	131,703	167,894
Net cash (used in) provided by financing activities	252,388,605	10,034,016	23,884,176
Net (decrease) increase in cash	205,997,425	(20,052,381)	(2,597,374)
Cash at beginning of period	13,968,742	34,021,123	36,618,497
Cash at end of period	219,966,167	13,968,742	34,021,123
Supplemental disclosures of cash flow information:
Interest paid	1,287,506	771,966	865,278
Supplemental disclosures of non-cash financing activity:
Establishment of warrant liabilities in connection with common stock issuance			$ 2,145,000
Issuance of warrants in connection with debt financing	$ 387,000	$ 37,842