Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities:
Net loss	$ (32,866)	$ (55,185)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	379	111
Stock-based compensation expense	2,088	2,220
Amortization of debt issuance costs and discount	1,303	1,201
Warrant liabilities fair value adjustment	(30,365)	5,214
Derivative liability fair value adjustment	(1,170)	(2,257)
Noncash operating lease expense for right-of-use asset	198	192
Loss on extinguishment of debt	2,725	1,766
Noncash consideration associated with common stock purchase agreement	0	602
Changes in operating assets and liabilities:
Prepaid expenses, other assets, deferred costs, and other	1,597	(922)
Accounts receivable	(861)	0
Inventory	(5,292)	0
Accounts payable	2,763	(2,600)
Accrued expenses, other liabilities, and other	4,941	304
Net cash used in operating activities	(54,560)	(49,354)
Cash flows from investing activities:
Maturities of investments	0	20,713
Purchases of property and equipment	0	(4)
Purchase of intangible assets	(1,172)	0
Purchase of investments	0	(14,235)
Net cash (used in) provided by investing activities	(1,172)	6,474
Cash flows from financing activities:
Proceeds from common stock issued	38,552	90,554
Payments of offering costs and underwriting discounts and commissions	(205)	(5,879)
Proceeds from loan payable	30,000	0
Payments of loan payable issuance costs	(1,253)	0
Proceeds from employee stock purchase plan issuances	22	28
Repurchase of shares to satisfy tax withholdings	4	(208)
Proceeds from senior convertible notes	0	10,000
Payments of senior convertible notes issuance costs	0	(494)
Net cash provided by financing activities	67,120	94,001
Net increase in cash, cash equivalents, and restricted cash	11,388	51,121
Cash, cash equivalents, and restricted cash at beginning of period	93,314	42,193
Cash, cash equivalents, and restricted cash at end of period	104,702	93,314
Supplemental cash flow information:
Cash paid for interest	2,255	1,088
Cash received for interest	24	186
Noncash financing and investing activities:
Purchased intangible assets included in accounts payable and accrued expenses	78	0
Deferred offering and issuance costs included in accounts payable	430	62
Deferred offering costs reclassified to additional paid-in capital	86	153
Common stock issued for settlement of senior convertible notes	7,452	5,221
Common stock issued for Commitment Shares	0	602
Reclass of warrant liability to additional paid in capital	298	0
Reclass of deferred asset associated with issuance of loan payable to debt discount	390	0
Settlement of liability for exercise of warrants	$ 3,091	$ 0