Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Operating activities:
Net loss	$ (19,479,000)	$ (16,702,000)
Adjustments required to reconcile net loss to net cash used in operating activities:
Acquired in-process research and development		5,691,000
Depreciation	1,351,000	1,351,000
Stock-based compensation	4,271,000	46,000
Non-cash interest expense	918,000	1,013,000
Change in fair value of derivative liability	(1,117,000)	(1,724,000)
Loss on sale of assets (Note 6)	663,000	145,000
Amortization of premiums of available-for-sale securities		33,000
Changes in operating assets and liabilities:
Other non-cash adjustments, net	918,000	1,013,000
Accounts payable and accrued liabilities	(1,374,000)	144,000
Accrued compensation	(853,000)
Deferred rent and lease liabilities, net	(310,000)	(287,000)
Prepaid expenses and other current assets	348,000	(337,000)
Net cash used in operating activities	(15,582,000)	(10,627,000)
Investing activities:
Purchases of available-for-sale securities		(3,392,000)
Proceeds from sales and maturities of available-for-sale securities		13,016,000
Purchases of property and equipment	(224,000)	(875,000)
Proceeds from sale of property and equipment	93,000	65,000
Cash acquired in reverse merger transaction	3,008,000
Net cash provided by investing activities	2,877,000	8,814,000
Financing activities:
Payment of deferred consideration for asset acquisition	(1,000,000)
Proceeds from sale of common stock, net of offering costs	9,975,000
Net cash provided by financing activities	8,975,000
Net increase (decrease) in cash, cash equivalents and restricted cash	(3,730,000)	(1,813,000)
Cash, cash equivalents and restricted cash, beginning of period	10,463,000	12,276,000
Cash, cash equivalents and restricted cash, end of period	6,733,000	10,463,000
Supplemental schedule of non-cash investing and financing activities:
Issuance of common stock in reverse merger transaction	10,709,000
Conversion of deferred asset acquisition consideration upon reverse merger	1,463,000
Property and equipment included in accounts payable	36,000	$ 113,000
Unpaid offering costs	$ 116,000