Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 33,410	$ 85,451
Marketable securities, current	82,816	39,633
Prepaid expenses	4,889	2,318
Grants revenue receivable	3,490	7,100
Accounts receivable, related party	301	408
In-process research and development - held for sale	4,500	4,500
Other current assets	249	489
Total current assets	129,655	139,899
Marketable securities, non-current	2,000	1,510
Operating lease right-of-use assets, non-current	11,589	9,959
Property and equipment, net	20,889	18,158
Other assets	5,244	4,676
Total assets	169,377	174,202
Current liabilities:
Accounts payable	2,565	1,465
Accrued liabilities	13,231	14,544
Deferred revenue, current	12,496	8,511
Deferred revenue, current, related party	4,566	8,780
Other current liabilities, related party	5,498	0
Other current liabilities	2,041	2,501
Total current liabilities	40,397	35,801
Deferred revenue, long-term	7,785	18,944
Deferred revenue, long-term, related party	935	441
Long-term debt, net	14,822	2,940
Operating lease liabilities, non-current	12,828	11,682
Other liabilities, related party	6,711	0
Other liabilities	1,458	1,366
Total liabilities	84,936	71,174
Commitments and contingencies (Note 10)	0	0
Stockholders’ equity
Preferred stock, $0.001 par value: Authorized: 2,000,000 shares at September 30, 2020 and December 31, 2019; issued and outstanding: 250 shares at September 30, 2020 and December 31, 2019	0	0
Common stock, $0.001 par value: Authorized: 150,000,000 shares at September 30, 2020 and December 31, 2019; issued and outstanding: 49,963,732 shares at September 30, 2020 and 45,589,157 shares at December 31, 2019	50	46
Additional paid-in capital	324,914	267,089
Accumulated other comprehensive income	73	18
Accumulated deficit	(240,596)	(164,125)
Total stockholders’ equity	84,441	103,028
Total liabilities and stockholders’ equity	$ 169,377	$ 174,202