Condensed Consolidated Balance Sheets (unaudited) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 216,213	$ 284,803
Short-term investments (amortized cost of $384,005)	383,011	328,359
Grants receivable	433	1,001
Refundable income taxes	3,250	1,434
Prepaid expenses and other currents assets	11,640	12,701
Total current assets	614,547	628,298
Property and equipment, net	2,548	2,121
Long-term investments (amortized cost of $78,886)	78,260	118,225
Research and development tax credits receivable	1,882	1,128
Restricted cash	270	235
Right of use assets	5,427	4,652
Other assets	812	332
Total assets	703,746	754,991
Current liabilities:
Accounts payable	5,227	7,662
Accrued expenses and other current liabilities	21,247	19,727
Deferred income	2,528	1,180
Deferred revenue	0	12,595
Lease liabilities	1,021	836
Total current liabilities	30,023	42,000
Grants repayable, net of current portion	6,570	6,622
Lease liabilities, net of current portion	4,427	3,837
Unrecognized tax benefits	39,200	39,200
Total liabilities	80,220	91,659
Commitments and contingencies (Note 10)
Stockholders’ equity:
Common stock, $0.001 par value: 150,000,000 shares authorized at June 30, 2023 and December 31, 2022 respectively; 35,781,919 and 35,611,219 shares issued and outstanding; respectively	36	36
Additional paid-in capital	449,232	435,665
Accumulated other comprehensive loss	(13,166)	(9,644)
Retained earnings	187,424	237,275
Total stockholders’ equity	623,526	663,332
Total liabilities and stockholders’ equity	$ 703,746	$ 754,991