Condensed Consolidated Balance Sheets (unaudited) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 21,785	$ 13,711
Contracts and grants receivable	189	419
Deferred offering costs	58	49
Prepaid expenses and other current assets	1,420	1,545
Total current assets	23,452	15,724
Restricted cash	539	540
Intangible assets	75	75
Other assets	387	419
Property and equipment, net	10,231	10,506
Right-of-use lease assets	1,826	1,833
Total assets	36,510	29,097
Current liabilities:
Accounts payable	997	1,602
Accrued compensation	1,107	437
Accrued outside research and development services	1,928	1,013
Accrued legal and professional fees	173	616
Other accrued expenses	428	553
Deferred revenue, current portion	4,401	4,428
Research and development service obligation liability, current portion	1,566	3,088
Lease liabilities, current portion	1,167	1,162
Total current liabilities	11,767	12,899
Deferred revenue, net of current portion	5,960	7,076
Lease liabilities, net of current portion	4,947	5,100
Research and development service obligation liability, net of current portion	736	727
Research and development funding arrangement liability, related party	25,000	25,000
Other long-term liabilities	460	578
Total liabilities	48,870	51,380
Commitments and contingencies (Note 8)
Stockholders’ deficit
Common stock $0.0001 par value; 200,000,000 shares authorized as of March 31, 2020 and December 31, 2019; 72,028,562 and 26,744,300 shares issued as of March 31, 2020 and December 31, 2019, respectively; 72,019,062 and 26,734,800 shares outstanding as of March 31, 2020 and December 31, 2019, respectively	7	3
Additional paid-in capital	213,939	197,853
Treasury stock at cost, 9,500 shares as of March 31, 2020 and December 31, 2019	(155)	(155)
Accumulated deficit	(226,151)	(219,984)
Total stockholders’ deficit	(12,360)	(22,283)
Total liabilities and stockholders’ deficit	$ 36,510	$ 29,097