Condensed Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Cash flows from operating activities
Net loss	$ (39,616)	$ (30,575)
Adjustments to reconcile net loss to net cash used in operations:
Depreciation and amortization	1,425	1,040
Impairment of property and equipment	60	664
Share-based compensation expense	11,935	12,345
Non-cash interest expense		(10)
Inventory write-downs	60
Net accretion of premium on short-term investments	290
Gain on extinguishment of debt		(692)
Change in:
Inventory	(42)	(1,182)
Other current and non-current assets	(662)	(3,038)
Accounts payable	(2,160)	573
Accrued liabilities	418	390
Contract liabilities and other current liabilities	(386)	(59)
Operating lease liabilities	(938)	(506)
Other long-term liabilities		(195)
Net cash used in operating activities	(29,616)	(21,245)
Cash flows from investing activities
Sales of investment securities	34,700
Purchases of investment securities	(63,726)
Purchases of property and equipment	(2,017)	(2,034)
Net cash used in investing activities	(31,043)	(2,034)
Cash flows from financing activities
Principal payments under finance leases	(20)	(25)
Principal payments under long-term debt	(392)
Payments received on subscriptions receivable		6,135
Proceeds from stock option exercises	727	2,540
Net proceeds from issuance of common stock		122,902
Net cash provided by financing activities	315	131,552
Change in cash, cash equivalents, and restricted cash	(60,344)	108,273
Cash, cash equivalents, and restricted cash at beginning of period	83,739	17,297
Cash, cash equivalents, and restricted cash at end of period	23,395	125,570
Supplemental schedule of non-cash investing and financing activities
Non-cash additions to property and equipment	$ 645	$ 298