Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets
Cash and cash equivalents	$ 82,647	$ 16,862
Investment securities, available-for-sale	32,720
Inventory	1,780
Other current assets	2,283	698
Total current assets	119,430	17,560
Property and equipment, net	3,026	1,883
Operating lease right-of-use asset	5,577	946
Restricted cash	1,092	435
Intangible assets, net	115	164
Other assets	985	18
Total assets	130,225	21,006
Current liabilities
Accounts payable	3,584	630
Accrued liabilities	1,170	495
Contract liabilities	5,265	7,765
Other current liabilities	1,181
Current portion of long-term debt	392	431
Current portion of operating lease liability	849	676
Current portion of finance lease obligations	21	31
Total current liabilities	12,462	10,028
Long-term debt, net of current portion		1,151
Operating lease liability, net of current portion	4,983	774
Finance lease obligations, net of current portion	26	44
Total liabilities	17,471	11,997
Shareholders' equity
Preferred stock, par value $0.001; 25,000 shares authorized; no and     no shares issued and outstanding
Common stock, par value $0.001; 210,000 shares authorized;     164,363 and 152,926 shares issued and outstanding at December 31,     2021 and 2020, respectively	164	153
Additional paid-in capital	742,042	601,224
Subscriptions receivable		(6,135)
Accumulated other comprehensive loss	(19)
Accumulated deficit	(629,433)	(586,233)
Total shareholders' equity	112,754	9,009
Total liabilities and shareholders' equity	$ 130,225	$ 21,006