CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Operating activities
Net loss	$ (79,727)	$ (76,941)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	20,565	17,495
Depreciation and amortization	1,779	1,392
Premiums and discounts on available-for-sale marketable securities	(2,743)	1,852
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(3,994)	630
Contract asset—due from related parties	(1,585)	(2,234)
Accounts payable	(513)	(1,847)
Accrued expenses and other current liabilities	(6,252)	(1,720)
Deferred revenue	(18,537)	(17,503)
Operating lease right-of-use assets	2,055	245
Operating lease liabilities	9,554	(479)
Other assets and liabilities	174	(170)
Net cash used in operating activities	(79,224)	(79,280)
Investing activities
Purchase of property and equipment, net	(14,777)	(1,217)
Purchases of investments	(114,477)	(144,827)
Maturities of investments	189,677	253,710
Net cash provided by investing activities	60,423	107,666
Financing activities
Proceeds from stock option exercises	2,163	826
Proceeds from employee stock purchase plan	962	256
Payments on finance leases	(661)	(533)
Net cash provided by financing activities	2,464	549
Net (decrease) increase in cash, cash equivalents and restricted cash	(16,337)	28,935
Cash, cash equivalents and restricted cash at beginning of period	74,524	54,092
Cash, cash equivalents and restricted cash at end of period	58,187	83,027
Supplemental disclosure of cash flow activities
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	48,833	0
Cash paid for interest	78	86
Supplemental disclosure of noncash investing and financing activities
Property and equipment purchases included in accounts payable and accrued expenses	1,061	745
Purchase of property and equipment through finance lease	0	340
Cash and cash equivalents	52,386	76,914
Restricted cash	5,801	6,113
Total cash, cash equivalents, and restricted cash	$ 58,187	$ 83,027