Condensed Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 25,970	$ 38,129
Investments in marketable securities	184,484	213,171
Prepaid expenses and other current assets	3,328	4,058
Total current assets	213,782	255,358
Property and equipment, net	49,384	43,020
Operating lease right-of-use assets	11,353	11,685
Restricted cash, noncurrent	399	547
Other noncurrent assets	6,579	3,579
Total assets	281,497	314,189
Current liabilities:
Accounts payable	8,888	10,721
Accrued expenses and other current liabilities	8,132	9,059
Operating lease liabilities, current	2,075	1,994
Total current liabilities	19,095	21,774
Operating lease liabilities, noncurrent	13,093	13,707
Other noncurrent liabilities	212	182
Total liabilities	32,400	35,663
Commitments and contingencies (Note 6)
Stockholders' equity:
Common stock	4	4
Additional paid-in capital	436,313	434,196
Accumulated other comprehensive loss	(631)	(141)
Accumulated deficit	(186,589)	(155,533)
Total stockholders' equity	249,097	278,526
Total liabilities and stockholders' equity	$ 281,497	$ 314,189