Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities:
Net loss	$ (7,883)	$ (4,669)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	4	5
Amortization	40	38
Noncash stock based compensation	621	490
Noncash interest	101
Changes in operating assets and liabilities:
Prepaid expenses and other assets	168	229
Accounts payable and accrued expenses	(891)	(1,015)
Lease liability	(44)	(39)
Net cash used in operating activities	(7,884)	(4,961)
Cash flows from investing activities:
Acquisition of property and equipment	(164)
Net cash used in investing activities	(164)
Cash flows from financing activities:
Proceeds from issuance of common stock in private placement, net of offering costs		7,810
Proceeds from issuance of long-term debt	20,000
Debt financing costs paid	(1,059)
Proceeds from exercise of stock options	119
Net cash provided by financing activities	67,494	8,670
Net increase in cash and cash equivalents	59,446	3,709
Cash and cash equivalents, beginning of period	34,479	7,851
Cash and cash equivalents, end of period	93,925	11,560
Supplemental disclosure of noncash financing activities
Warrants issued in connection with long-term debt	3,570
Supplemental cash flow information
Interest paid	297
At-the-market sales
Cash flows from financing activities:
Proceeds from sales or issuance of common stock, net of offering costs		$ 860
Public offering
Cash flows from financing activities:
Proceeds from sales or issuance of common stock, net of offering costs	$ 48,434