Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net loss	$ (30,774)	$ (13,335)
Loss from discontinued operations		(1,494)
Loss from continuing operations	(30,774)	(11,841)
Adjustments to reconcile net loss from continuing operations to net cash used in operating activities:
Depreciation and amortization	1,958	1,963
Noncash lease expense	386
Stock-based compensation expense	825	1,263
Change in fair value of stock warrants	6,964	(522)
Change in fair value of contingent consideration	289	567
Gain on deconsolidation of former subsidiary		(1,994)
Operating loss of minority interest investment	478	160
Change in operating assets and liabilities:
Prepaid expenses, other current assets and other assets	10	(60)
Due from related party	64	(64)
Accounts payable	1,061	249
Accrued compensation	9	(103)
Accrued clinical trial site costs	1,679	321
Operating lease liabilities	(360)
Other liabilities	36	(261)
Net cash used in continuing operating activities	(17,375)	(10,322)
Net cash used in discontinued operating activities		(1,361)
Net cash used in operating activities	(17,375)	(11,683)
Cash flows from investing activities:
Purchases of property and equipment	(21)	(8)
Security deposit on sublease	(59)
Security deposit received from expired lease	108
Proceeds from sale of minority interest investment in former subsidiary	500
Net cash provided by (used in) continuing investing activities	528	(8)
Net cash used in discontinued investing activities		(172)
Net cash provided by (used in) investing activities	528	(180)
Cash flows from financing activities:
Proceeds from sale of common stock and common stock warrants, net of costs	14,483	16,302
Principal paid on finance lease liabilities	(2)
Net cash provided by continuing financing activities	14,481	16,302
Net cash provided by discontinued financing activities		1,525
Net cash provided by financing activities	14,481	17,827
Net increase (decrease) in cash and cash equivalents	(2,366)	5,964
Cash and cash equivalents, beginning of period	23,099	17,135
Cash and cash equivalents, end of period	20,733	23,099
Supplemental disclosures of non-cash investing and financing information
Accrued liability for cost of issuing common stock		52
Warrants issued in connection with sale of common stock		582
Continuing Operations [Member]
Cash flows from financing activities:
Net increase (decrease) in cash and cash equivalents	$ (2,366)	5,972
Discontinued Operations [Member]
Cash flows from financing activities:
Net increase (decrease) in cash and cash equivalents		$ (8)