Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating activities
Net loss	$ (17,910)	$ (18,346)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation, amortization and accretion	144	110
Stock-based compensation expense	2,469	1,599
Noncash interest expense	1,521	335
Changes in operating assets and liabilities
Accounts receivable, other receivables, prepaid, and other current assets	4,234	(240)
Inventories	(6,900)	(2,734)
Operating lease right-of-use asset	221	236
Accounts payable and accrued expenses	(2,010)	(421)
Operating lease liability	(245)	(102)
Other liabilities and other assets	(634)	(1,955)
Net cash used in operating activities	(19,110)	(21,518)
Investing activities
Purchase of fixed assets	(36)	(262)
Purchase of marketable securities	(15,160)	0
Proceeds from maturities of marketable securities	0	20,000
Net cash (used) provided by investing activities	(15,196)	19,738
Financing activities
Payment of long-term royalty-backed loan agreement debt issuance costs	0	(397)
Proceeds from sale of common stock, net of costs	3,091	0
Proceeds from the employee stock purchase plan and stock options	6	3
Net cash (used) provided by financing activities	3,097	(394)
Net (decrease) increase in cash, cash equivalents and restricted cash	(31,209)	(2,174)
Cash, cash equivalents and restricted cash at beginning of period	80,617	106,048
Cash, cash equivalents and restricted cash at end of period	49,408	103,874
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION
Cash paid for interest	1,181	975
SUPPLEMENTAL DISCLOSURES OF NONCASH FINANCING ACTIVITIES
Paid in-kind interest included in accrued expenses	$ 1,161	$ 0