Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 254,154	$ 112,637
Short-term investment securities		27,798
Prepaid research and development	5,540	8,105
Other current assets	641	611
Total current assets	260,335	149,151
Restricted cash	1,257	1,251
Leasehold interest, net	2,104	2,129
Equipment, net	378	282
Right-of-use-assets	8,983	9,402
Goodwill	799	799
Total assets	273,856	163,014
Current liabilities:
Accounts payable and accrued expenses	34,659	30,041
Other current liabilities	21,735	48,994
Loan payable - current portion	14,590
Lease liability - current portion	1,614	1,616
Accrued compensation	5,072	3,798
Total current liabilities	77,670	84,449
Deferred revenue, net of current portion	648	762
Long-term debt	15,074	28,970
Lease liability - non-current	9,806	10,218
Total liabilities	103,198	124,399
Commitments and contingencies
Stockholders' equity:
Common stock, $0.001 par value per share (150,000,000 shares authorized, 128,959,861 and 109,425,243 shares issued, 128,918,552 and 109,383,934 shares outstanding at September 30, 2020 and December 31, 2019, respectively)	129	109
Additional paid-in capital	1,063,142	739,956
Treasury stock, at cost, 41,309 shares at September 30, 2020 and December 31, 2019	(234)	(234)
Accumulated deficit	(892,379)	(701,216)
Total stockholders' equity	170,658	38,615
Total liabilities and stockholders' equity	$ 273,856	$ 163,014