Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 146,261	$ 89,893
Restricted cash	0	279
Accounts receivable	12,626	5,000
Prepaid expenses and other current assets	7,615	1,495
Total current assets	166,502	96,667
Property and equipment, net	1,363	1,222
Right-of-use asset, net	11,216	301
Long-term restricted cash	1,379	1,379
Other assets	536	0
Total assets	180,996	99,569
Current liabilities:
Accounts payable	471	500
Accrued expenses	11,285	13,492
Loan payable	0	18,905
Lease liability	875	372
Deferred revenue	64,373	1,674
Total current liabilities	77,004	34,943
Non-current liabilities:
Loan payable, net of current portion	24,589	0
Lease liability	9,886	0
Deferred revenue	51,466	14,680
Warrant liabilities	25,433	41,549
Total liabilities	188,378	91,172
Commitments and contingencies (Note 17)
Stockholders’ (deficit) equity :
Preferred stock, $0.0001 par value; 10,000,000 shares authorized; no shares issued and outstanding at September 30, 2020 and December 31, 2019, respectively	0	0
Common stock, $0.0001 par value; 200,000,000 shares authorized; 107,235,976 and 86,325,547 shares issued and outstanding as of September 30, 2020 and December 31, 2019, respectively	11	9
Additional paid-in capital	386,374	348,664
Accumulated deficit	(389,183)	(335,753)
Accumulated other comprehensive loss	(4,584)	(4,523)
Total stockholders’ (deficit) equity	(7,382)	8,397
Total liabilities and stockholders’ (deficit) equity	$ 180,996	$ 99,569