Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 20,051	$ 20,645
Prepaid and other assets	736	565
Total current assets	20,787	21,210
Right-of-use asset	190
Other assets	767	752
Total assets	21,744	21,962
Current liabilities:
Accounts payable	871	3,440
Accrued liabilities	2,731	891
Deferred grant revenue	3,640
Current portion of lease liability	99
Total current liabilities	7,341	4,331
Preferred stock warrant liability	1,300	674
Lease liability	91
Commitments and contingencies (Notes 3 and 5)
Convertible preferred stock, $0.0001 par value; authorized shares - none and 130,100 at December 31, 2019 and 2018, respectively; issued and outstanding – none and 8,148 at December 31, 2019 and 2018, respectively; liquidation preference of none and $48,954 at December 31, 2019 and 2018, respectively		46,588
Stockholders’ equity (deficit):
Preferred stock, $0.001 par value, authorized shares – 5,000 and none at December 31, 2019 and 2018, respectively; issued and outstanding shares – none
Common stock, $0.001 par value; authorized shares – 60,000 and 200,000 at December 31, 2019 and 2018, respectively; issued and outstanding shares – 15,387 and 3,762 at December 31, 2019 and 2018, respectively	15	5
Additional paid-in capital	79,869	1,748
Accumulated deficit	(65,572)	(31,384)
Total stockholders’ equity (deficit)	14,312	(29,631)
Total liabilities and stockholders’ equity (deficit)	$ 21,744	$ 21,962