Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 104,484	$ 93,041
Prepaid expenses and other current assets	3,569	5,165
Accounts receivable, net	861	0
Inventory	463	0
Total current assets	109,377	98,206
Other assets	6,122	573
Deferred offering costs	150	187
Restricted cash	218	273
Property and equipment, net	113	298
Intangible assets, net	1,056	0
Operating lease right-of-use asset (Note 9)	2,801	2,999
Total assets	119,837	102,536
Current liabilities:
Accounts payable	7,848	4,639
Accrued expenses	5,698	4,141
Warrant liabilities	0	17,564
Operating lease liability, current portion (Note 9)	70	52
Total current liabilities	13,616	26,396
Other liabilities	3,345	0
Warrant liabilities	18,062	33,592
Convertible debt and derivative liabilities (Note 8)	11,607	16,516
Loan payable (Note 8)	28,745	0
Operating lease liability (Note 9)	3,204	3,274
Total liabilities	78,579	79,778
Commitments and contingencies	0	0
Stockholders’ equity:
Preferred stock, $0.001 par value, authorized 5,000,000 shares as of December 31, 2021 and December 31, 2020; 0 shares issued and outstanding as of December 31, 2021 and December 31, 2020	0	0
Common stock, $0.001 par value, 100,000,000 shares authorized as of December 31, 2021, and December 31, 2020; 28,705,334 and 19,663,698 shares issued and outstanding as of December 31, 2021, and December 31, 2020, respectively	32	20
Additional paid-in capital	400,705	349,351
Accumulated deficit	(359,479)	(326,613)
Total stockholders’ equity	41,258	22,758
Total liabilities and stockholders’ equity	$ 119,837	$ 102,536