CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Assets, Current [Abstract]
Cash and cash equivalents	$ 394,583	$ 64,179
Marketable securities	307,434	190,656
Restricted cash, current	1,903	0
Prepaid expenses and other current assets	12,443	12,028
Total current assets	716,363	266,863
Restricted cash, non-current	2,418	2,501
Marketable securities, non-current	27,168	0
Property and equipment, net	42,728	11,231
Operating lease right-of-use assets	27,099	28,659
Prepaid research and development expenses and other long-term assets	9,356	4,563
Total assets	825,132	313,817
Current liabilities:
Accounts payable	2,619	9,053
Accrued liabilities	18,302	11,679
Operating lease liabilities, current portion	7,501	2,901
Finance lease liabilities, current portion	39,283	33,060
Less: current portion	50,533
Total current liabilities	118,238	56,693
Operating lease liabilities, net of current portion	50,841	31,299
Finance lease liabilities, net of current portion		20,871
Noncurrent portion	170,673	0
Total liabilities	339,752	108,863
Commitments and Contingencies (Note 11)
Stockholders' equity
Common stock, par value of $0.001 per share; 1,000,000,000 shares authorized and 52,280,077 shares issued and outstanding as of December 31, 2023; 1,000,000,000 shares authorized and 44,105,981 shares issued and outstanding as of December 31, 2022	52	44
Additional paid-in capital	874,261	523,921
Accumulated other comprehensive income (loss)	547	(221)
Accumulated Deficit	(389,480)	(318,790)
Total stockholders' equity	485,380	204,954
Total liabilities and stockholders' equity	$ 825,132	$ 313,817