Condensed Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current assets
Cash and cash equivalents	$ 7,805	$ 5,837
Accounts receivable, net of allowances of $0 and $0, respectively	0	1,079
Inventory	0	192
Other current assets	301	729
Total current assets	8,106	7,837
Property and equipment, net	1,623	1,849
Operating lease right-of-use asset	1,132	1,308
Restricted cash	435	435
Intangible assets	192	221
Other assets	18	186
Total assets	11,506	11,836
Current liabilities
Accounts payable	1,498	1,871
Accrued liabilities	501	2,045
Deferred revenue	0	21
Contract liabilities	8,699	9,755
Other current liabilities	0	83
Current portion of long-term debt	694	0
Current portion of operating lease liability	666	656
Current portion of finance lease obligations	20	25
Total current liabilities	12,078	14,456
Long-term debt, net of current portion	880	0
Operating lease liability, net of current portion	1,069	1,348
Finance lease obligations, net of current portion	1	9
Total liabilities	14,028	15,813
Commitments and contingencies (Note 10)
Shareholders' equity (deficit)
Preferred stock, par value $0.001; 25,000 shares authorized; 0 and 0 shares issued and outstanding	0	0
Common stock, par value $0.001; 150,000 shares authorized; 143,433 and 125,803 shares issued and outstanding at June 30, 2020 and December 31, 2019, respectively	143	126
Additional paid-in capital	577,172	568,496
Accumulated deficit	(579,837)	(572,599)
Total shareholders' equity (deficit)	(2,522)	(3,977)
Total liabilities and shareholders' equity (deficit)	11,506	11,836
Reconciliation of cash, cash equivalents, and restricted cash balances
Cash and cash equivalents	7,805	5,837
Restricted cash	435	435
Cash, cash equivalents, and restricted cash	$ 8,240	$ 6,272