Unaudited Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 95,210	$ 104,484
Prepaid expenses and other current assets	3,919	3,569
Accounts receivable, net	1,628	861
Inventory	1,149	463
Total current assets	101,906	109,377
Other assets	5,543	6,122
Deferred offering costs	124	150
Restricted cash	218	218
Property and equipment, net	61	113
Intangible assets, net	961	1,056
Operating lease right-of-use asset (See Note 7)	2,749	2,801
Total assets	111,562	119,837
Current liabilities:
Accounts payable	8,130	7,848
Accrued expenses	4,523	5,698
Other liabilities, current portion (See Note 6)	174	0
Warrant liabilities	40	0
Operating lease liability, current portion (See Note 7)	77	70
Total current liabilities	12,944	13,616
Other liabilities (See Note 6)	4,102	3,345
Warrant liabilities	7,921	18,062
Convertible debt and derivative liability (See Note 6)	10,817	11,607
Loan payable	33,713	28,745
Operating lease liability (See Note 6)	3,138	3,204
Total liabilities	72,635	78,579
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.001 par value, authorized 5,000,000 shares as of March 31, 2022 and December 31, 2021; 0 shares issued and outstanding as of March 31, 2022 and December 31, 2021	0	0
Common stock, $0.001 par value, 100,000,000 shares authorized as of March 31, 2022 and December 31, 2021; 29,221,158 and 28,705,334 shares issued and outstanding as of March 31, 2022 and December 31, 2021, respectively	32	32
Additional paid-in capital	403,825	400,705
Accumulated deficit	(364,930)	(359,479)
Total stockholders’ equity	38,927	41,258
Total liabilities and stockholders’ equity	$ 111,562	$ 119,837