Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (519,021)	$ (481,192)	$ (474,186)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	10,285	8,976	7,572
(Gain) loss on disposal of property and equipment	(76)	72	(162)
Stock-based compensation	154,273	134,050	91,400
(Accretion) amortization of investment discounts and premiums	(17,817)	(25,897)	4,003
(Recognition) deferral of equity method investment intra-entity profit on sales	(20,967)	6,624	11,405
Change in fair value of investments, net	32,565	0	0
Loss from equity method investment	0	15,633	11,079
Change in fair value of contingent consideration	0	100	13,485
In-process research and development expense	0	0	55,990
Changes in operating assets and liabilities:
Accounts receivable	27,939	(32,688)	(1,737)
Prepaid expenses and other current assets	5,184	(27,168)	(2,160)
Operating lease right-of-use assets	21,466	19,011	13,121
Other assets	917	(707)	(1,091)
Accounts payable	6,800	2,522	(4,584)
Accrued expenses	(10,383)	6,024	15,924
Deferred revenue	(22,076)	(2,778)	(63,464)
Operating lease liabilities	(17,969)	(16,668)	(9,882)
Net cash used in operating activities	(348,880)	(394,086)	(333,287)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(5,778)	(13,985)	(13,558)
Purchases of marketable securities	(935,573)	(904,464)	(429,032)
Sales and maturities of marketable securities	1,066,918	887,102	647,581
Proceeds from sale of property and equipment	0	0	150
Acquired in-process research and development, net of cash acquired of $287	0	0	(44,832)
Net cash provided by (used in) investing activities	125,567	(31,347)	160,309
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from options exercised	5,862	6,599	14,517
Issuance of shares through employee stock purchase plan	2,986	3,929	2,649
Net cash provided by financing activities	185,747	130,323	582,955
Net (decrease) increase in cash, cash equivalents and restricted cash equivalents	(37,566)	(295,110)	409,977
Cash, cash equivalents and restricted cash equivalents, beginning of period	240,353	535,463	125,486
Cash, cash equivalents and restricted cash equivalents, end of period	202,787	240,353	535,463
Reconciliation of cash, cash equivalents and restricted cash equivalents to consolidated balance sheet:
Cash and cash equivalents	189,182	226,748	523,506
Restricted cash equivalents, included in investments and other assets	13,605	13,605	11,957
Total cash, cash equivalents and restricted cash equivalents	202,787	240,353	535,463
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Purchases of property and equipment unpaid at period end	577	1,525	1,623
Operating lease liabilities arising from obtaining right-of-use assets	112,821	1,311	67,053
Non-cash trade-in of property and equipment	99	0	200
Proceeds from at-the-market offerings unpaid at period end	0	2,075	0
Shares issued for Rewrite contingent consideration	0	24,126	0
Contingent consideration liability assumed in asset acquisition	0	0	10,541
At The Market Offerings [Member]
CASH FLOWS FROM FINANCING ACTIVITIES:
Net proceeds from issuance of common stock	176,899	119,795	227,897
Follow-on public Offerings [Member]
CASH FLOWS FROM FINANCING ACTIVITIES:
Net proceeds from issuance of common stock	$ 0	$ 0	$ 337,892