CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 41,541	$ 46,842	[1]
Restricted cash	215	215	[1]
Accounts receivable, net	4,324	4,633	[1]
Prepaid expenses and other current assets	1,657	2,324	[1]
Total current assets	47,737	54,014	[1]
Property and equipment, net	3,424	3,622	[1]
Right-of-use assets, operating leases	840	1,660	[1]
Other non-current assets	586	535	[1]
Total assets	52,587	59,831	[1]
Current liabilities:
Accounts payable	737	975	[1]
Accrued expenses and other current liabilities	4,608	6,176	[1]
Note payable, current	0	2,226	[1]
Operating lease liabilities	1,051	2,006	[1]
Total current liabilities	6,396	11,383	[1]
Note payable, net of current	0	1,094	[1]
Other long-term liabilities	1,075	1,096	[1]
Total liabilities	7,471	13,573	[1]
Commitments and contingencies (Note 13)
Stockholders’ equity:
Common stock, $0.001 par value - 142,857 shares authorized, 15,543 and 15,532 shares issued and outstanding at March 31, 2022 and December 31, 2021, respectively	15	15	[1]
Additional paid-in capital	352,248	351,394	[1]
Accumulated deficit	(306,106)	(304,107)	[1]
Accumulated other comprehensive loss	(1,041)	(1,044)	[1]
Total stockholders’ equity	45,116	46,258	[1]
Total liabilities and stockholders’ equity	$ 52,587	$ 59,831	[1]

[1] Derived from the Company’s audited consolidated financial statements as of December 31, 2021.