UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities:
Net loss	$ (11,983)	$ (16,322)
Adjustments to reconcile net loss to cash used in operating activities:
Depreciation and amortization	494	265
Amortization of right-of-use asset	518	249
Equity-based compensation	1,603	1,439
Amortization of long-term debt issuance costs and fees	39	139
Other	67	36
Change in fair value of warrant liabilities	(343)	(360)
Changes in operating assets and liabilities:
Unbilled revenue receivable and accounts receivable	(10)	3
Prepaid expenses and other current assets	(1,271)	(34)
Other noncurrent assets	(181)	0
Accounts payable	535	618
Accrued expenses and other current liabilities	(461)	176
Deferred revenue	(16,351)	14
Other noncurrent liabilities	(119)	(236)
Net cash used in operating activities	(27,463)	(14,013)
Cash flows from investing activities:
Purchase of available for sale securities	(47,349)	0
Proceeds from sale or maturity of available for sale securities	47,093	0
Capital expenditures	(3,074)	(462)
Net cash used in investing activities	(3,330)	(462)
Cash flows from financing activities:
Proceeds from common stock offering	2,973	63,250
Payment of common stock financing costs	(207)	(4,384)
Proceeds from long-term borrowing	17,500	0
Repayment of long-term debt	(4,999)	0
Payment of long-term debt fees and issuance costs	(344)	(284)
Proceeds from exercise of common stock options	69	17
Net cash provided by financing activities	14,992	58,599
Net (decrease) increase in cash, cash equivalents, and restricted cash	(15,801)	44,124
Cash, cash equivalents, and restricted cash - beginning of period	48,460	26,268
Cash, cash equivalents, and restricted cash - end of period	32,659	70,392
Non-cash operating activities:
Right-of-use asset acquired through operating leases	8,147	0
Non-cash investing activities:
Capital expenditures (accounts payable and accrued expenses)	13	339
Non-cash financing activities:
Debt fees (accrued expense and other noncurrent liabilities)	834	100
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Total cash, cash equivalents, and restricted cash shown in the unaudited condensed consolidated statements of cash flows	$ 32,659	$ 70,392