Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 28,614	$ 12,463
Investments		8,012
Accounts receivable	61
Inventory	5,824
Prepaid expenses and other current assets	2,131	1,864
Total current assets	36,630	22,339
Property and equipment, net	2,462	2,478
Intangible assets, net	3,216	3,882
Goodwill	2,791	2,791
Right-of-use assets	8,785	9,438
Other assets	365	365
Total assets	54,249	41,293
Current liabilities:
Accounts payable	2,904	1,717
Accrued expenses	4,389	5,326
Deferred revenue	16
Lease liability, current	774	542
Note payable, current	436
Total current liabilities	8,519	7,585
Lease liability, less current portion	10,040	10,814
Total liabilities	18,559	18,399
Commitments and contingencies (Note 13)
Stockholders' equity:
Preferred stock, $0.001 par value; authorized – 50,000 shares; no shares issued and outstanding
Common stock, $0.001 par value: authorized – 500,000 shares; issued and outstanding – 29,716 shares and 25,550 shares at December 31, 2021 and 2020, respectively	29	25
Additional paid-in-capital	271,861	195,410
Accumulated other comprehensive income (loss)		(1)
Accumulated deficit	(236,200)	(172,540)
Total stockholders' equity	35,690	22,894
Total liabilities and stockholders' equity	$ 54,249	$ 41,293