CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 78,267	$ 61,084
Short-term investments	26,184	64,993
Accrued interest	58	262
Unbilled grant receivables	354	298
Prepaid expenses and other current assets	2,425	676
Total current assets	107,288	127,313
Property and equipment	313	350
Operating lease right-of-use assets	10,245	11,759
Total assets	117,846	139,422
Current liabilities:
Accounts payable	680	630
Accrued expenses	4,546	5,163
Operating lease liability, current	3,147	3,067
Amount due to related party	542	246
Total current liabilities	8,915	9,106
Operating lease liability, long term	7,098	8,692
Total liabilities	16,013	17,798
Preferred stock
Preferred stock, value	173,127	173,127
Stockholders’ deficit:
Additional paid-in capital	4,886	3,748
Accumulated other comprehensive income	110	68
Accumulated deficit	(76,290)	(55,319)
Total stockholders’ deficit	(71,294)	(51,503)
Total liabilities, convertible preferred stock and stockholders’ deficit	117,846	139,422
Series B Preferred Stock
Preferred stock
Preferred stock, value	120,923	120,923
Series A Preferred Stock
Preferred stock
Preferred stock, value	$ 52,204	$ 52,204