CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 25,580	$ 24,581
Marketable securities	66,872	101,061
Accounts receivable	5,934	6,864
Inventory	14,859	11,934
Prepaid expenses and other current assets	5,460	2,326
Total current assets	118,705	146,766
Property and equipment, net	9,841	4,754
Restricted cash	500	500
Operating lease right-of-use assets	5,847
Other long-term assets		6
Total assets	134,893	152,026
Current liabilities:
Accounts payable	6,651	1,206
Accrued expenses and other current liabilities	16,337	10,410
Deferred revenue	250	263
Total current liabilities	23,238	11,879
Long-term debt, net of discount and current portion	35,197	34,657
Operating lease liabilities, net of current portion	8,604
Deferred rent, net of current portion		1,599
Total liabilities	67,039	48,135
Commitments and contingencies (Note 13)
Stockholders’ equity:
Preferred stock, no par value; 25,000,000 shares authorized; no shares issued or outstanding
Common stock, no par value; 150,000,000 shares authorized; 27,791,615 shares and 27,175,305 shares issued and outstanding at December 31, 2021 and 2020, respectively	510,488	502,217
Accumulated other comprehensive loss	(188)	(95)
Accumulated deficit	(442,446)	(398,231)
Total stockholders’ equity	67,854	103,891
Total liabilities and stockholders’ equity	$ 134,893	$ 152,026