Condensed Consolidated Statements of Cash Flows - USD ($)	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Operating activities:
Net loss	$ (9,788,000)	$ (7,938,000)
Adjustments required to reconcile net loss to net cash used in operating activities:
Depreciation	575,000	683,000
Stock-based compensation	1,950,000	725,000
Non-cash interest expense	300,000	536,000
Change in fair value of derivative liability		(1,117,000)
Changes in operating assets and liabilities:
Accounts payable and accrued liabilities	234,000	(599,000)
Accrued compensation	(357,000)	(351,000)
Deferred rent and lease liabilities, net	153,000	(168,000)
Prepaid expenses and other current assets	(1,155,000)	(57,000)
Net cash used in operating activities	(8,088,000)	(8,286,000)
Investing activities:
Purchases of property and equipment	(377,000)	(268,000)
Cash acquired in reverse merger transaction		3,008,000
Net cash used in (provided by) investing activities	(377,000)	2,740,000
Financing activities:
Payment of deferred consideration for asset acquisition	(1,000,000)	(1,000,000)
Proceeds from Paycheck Protection Program loan	718,000
Proceeds from sale of common stock, net of offering costs	22,919,000	9,975,000
Proceeds from exercises of warrants	81,000
Net cash provided by financing activities	22,718,000	8,975,000
Net increase in cash, cash equivalents and restricted cash	14,253,000	3,429,000
Cash, cash equivalents and restricted cash, beginning of period	6,733,000	10,463,000
Cash, cash equivalents and restricted cash, end of period	20,986,000	13,892,000
Supplemental schedule of non-cash investing and financing activities:
Issuance of common stock in reverse merger transaction		10,710,000
Conversion of deferred asset acquisition consideration upon reverse merger		1,462,000
Property and equipment included in accounts payable	7,000	$ 113,000
Unpaid offering costs	$ 91,000