Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Assets
Cash and cash equivalents	$ 777,624	$ 818,150
Prepaid expenses and other current assets	5,646	6,960
Income tax receivable	22,250	22,228
Total current assets	805,520	847,338
Property and equipment, net	4,922	4,912
Other assets	4,642	5,348
Total assets	815,084	857,598
Liabilities and stockholders’ equity
Accounts payable	8,255	4,790
Accrued direct research liabilities	12,618	14,023
Other current liabilities	14,443	22,264
Payable to collaborators	75,150	73,437
Deferred revenue	3,893	4,688
Total current liabilities	114,359	119,202
Other long-term liabilities	5,013	5,511
Liability related to sale of future royalties, net	326,379	315,454
Total noncurrent liabilities	331,392	320,965
Commitments and contingencies
Stockholders’ equity:
Additional paid-in capital	1,394,997	1,375,640
Accumulated deficit	(1,025,700)	(958,245)
Total stockholders’ equity	369,333	417,431
Total liabilities and stockholders’ equity	815,084	857,598
Common Stock A
Stockholders’ equity:
Common stock value	31	31
Total stockholders’ equity	31	31
Common Stock B
Stockholders’ equity:
Common stock value	5	5
Total stockholders’ equity	$ 5	$ 5