CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 104,454	$ 113,151
Accounts receivable	2,811	1,537
Receivable research incentives	9,296	8,190
Prepaid expenses and other current assets	4,155	5,139
Total current assets	120,716	128,017
Non-current assets:
Restricted cash	423	424
Property and equipment, net	5,429	5,126
Operating lease right of use assets	7,286	7,875
Finance lease right of use assets	1,471	1,602
Other non-current assets	642	701
Total non-current assets	15,251	15,728
Total assets	135,967	143,745
Current liabilities
Accounts payable	4,044	944
Deferred revenues	5,360	3,591
Operating lease liabilities, current	1,798	1,814
Accrued expenses and other current liabilities	4,183	8,406
Total current liabilities	15,385	14,755
Non-current liabilities
Loans payable, non-current	3,586	3,495
Operating lease liabilities, non-current	4,799	5,290
Deferred revenues, non-current	1,254	72
Other non-current liabilities	1,961	2,234
Total non-current liabilities	11,600	11,091
Total liabilities	26,985	25,846
Stockholders’ equity (deficit):
Additional paid-in capital	227,670	225,568
Accumulated other comprehensive loss	(4,746)	(4,653)
Accumulated deficit	(113,945)	(103,019)
Total stockholders’ equity (deficit)	108,982	117,899
Total liabilities, convertible preferred stock and stockholders’ equity (deficit)	135,967	143,745
Common stock
Stockholders’ equity (deficit):
Common stock	3	3
Class A common stock
Stockholders’ equity (deficit):
Common stock	$ 0	$ 0