Statements of Cash Flows - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net loss	$ (17,128,000)	$ (7,883,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	513,000	4,000
Amortization	33,000	40,000
Noncash stock-based compensation	742,000	621,000
Noncash interest	437,000	101,000
Changes in operating assets and liabilities:
Accounts receivable	543,000
Inventory	(1,590,000)
Prepaid expenses and other assets	421,000	168,000
Accounts payable and accrued expenses	1,393,000	(891,000)
Lease liability	(32,000)	(44,000)
Net cash used in operating activities	(14,668,000)	(7,884,000)
Cash flows from investing activities:
Sales and maturities of marketable securities	16,256,000
Acquisition of property and equipment	(71,000)	(164,000)
Net cash provided by (used in) investing activities	16,185,000	(164,000)
Cash flows from financing activities:
Proceeds from issuance of long-term debt		20,000,000
Debt financing costs paid		(1,059,000)
Proceeds from exercise of stock options	75,000	119,000
Net cash provided by financing activities	484,000	67,494,000
Net increase in cash and cash equivalents	2,001,000	59,446,000
Cash and cash equivalents, beginning of period	14,463,000	34,479,000
Cash and cash equivalents, end of period	16,464,000	93,925,000
Supplemental disclosure of noncash financing activities
Warrants issued in connection with long-term debt	1,080,000	3,570,000
Supplemental cash flow information
Interest paid	588,000	297,000
Public offering
Cash flows from financing activities:
Proceeds from issuance of common stock in public offering, net of offering costs		$ 48,434,000
At-the-market sales
Cash flows from financing activities:
Proceeds from issuance of common stock in public offering, net of offering costs	$ 409,000