Condensed Consolidated Balance Sheets (Unaudited) - USD ($)	Jun. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 298,007,000	$ 360,487,000
Short-term marketable securities	73,469,000	53,988,000
Prepaid expenses and other current assets	9,945,000	5,542,000
Total current assets	381,421,000	420,017,000
Long-term marketable securities	19,313,000	44,770,000
Property and equipment, net	24,191,000	15,954,000
Operating lease assets	14,778,000	17,356,000
Restricted cash	408,000	408,000
Other assets	4,712,000	2,910,000
Total assets	444,823,000	501,415,000
Current liabilities:
Accounts payable	2,291,000	4,677,000
Accrued expenses and other current liabilities	19,827,000	21,419,000
Operating lease liabilities	201,000	285,000
Total current liabilities	22,319,000	26,381,000
Operating lease liabilities, net of current portion	27,437,000	18,506,000
Total liabilities	49,756,000	44,887,000
Commitments and contingencies (Note 12)
Stockholders' equity:
Preferred stock, $0.0001 par value; 80,000,000 shares authorized as of June 30, 2022 and December 31, 2021; no shares issued and outstanding as of June 30, 2022 and December 31, 2021
Common stock, $0.0001 par value; 800,000,000 shares authorized as of June 30, 2022 and December 31, 2021; 122,063,473 and 121,382,547 shares issued at June 30, 2022 and December 31, 2021, respectively; 120,545,318 and 119,102,505 shares outstanding at June 30, 2022 and December 31, 2021, respectively	12,000	12,000
Additional paid-in capital	706,510,000	694,844,000
Accumulated other comprehensive loss	(1,223,000)	(162,000)
Accumulated deficit	(310,232,000)	(238,166,000)
Total stockholders' equity	395,067,000	456,528,000
Total liabilities and stockholders' equity	$ 444,823,000	$ 501,415,000