Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash flows from operating activities:
Net loss	$ (24,767)	$ (97,415)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation of property and equipment	24	71
Amortization of debt issuance costs	33	0
Amortization of discount/premium on investments	53	128
Share-based compensation	3,708	2,584
Fair value of common stock issued related to asset acquisition	0	43,445
Note payable related to asset acquisition	0	14,000
Gain on sale of investments	(1)	(2)
Lease-related amortization	63	41
Changes in operating assets and liabilities:
Accounts receivable	0	(159)
Inventories	(646)	0
Prepaid expenses and other assets	(1,002)	(309)
Accounts payable and accrued liabilities	(912)	(280)
Net cash used in operating activities	(23,447)	(37,896)
Cash flows from investing activities:
Purchases of property and equipment	0	(75)
Purchases of short-term investments	(5,258)	(91,944)
Purchases of long-term investments	0	(7,554)
Proceeds from sales of short-term investments	7,699	2,007
Proceeds from maturities of short-term investments	51,026	8,850
Net cash provided by (used in) investing activities	53,467	(88,716)
Cash flows from financing activities:
Proceeds from exercise of stock options	102	3,530
Proceeds from employee stock purchase plan	556	330
Proceeds from issuance of common stock, net of commissions	0	107,843
Payments of debt issuance costs	(118)	0
Payment of note payable related to asset acquisition	(14,000)	0
Net cash (used in) provided by financing activities	(13,460)	111,703
Net increase (decrease) in cash and cash equivalents	16,560	(14,909)
Cash and cash equivalents:
Beginning of period	15,397	46,989
End of period	$ 31,957	$ 32,080