Intellia Therapeutics (NTLA) 10-Q 8 Aug 24 2024 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2024	Aug. 02, 2024
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2024
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q2
Trading Symbol	NTLA
Entity Registrant Name	INTELLIA THERAPEUTICS, INC.
Entity Central Index Key	0001652130
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		101,579,188
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity File Number	001-37766
Entity Tax Identification Number	36-4785571
Entity Address, Address Line One	40 Erie Street
Entity Address, Address Line Two	Suite 130
Entity Address, City or Town	Cambridge
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02139
City Area Code	857
Local Phone Number	285-6200
Entity Incorporation, State or Country Code	DE
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Security Exchange Name	NASDAQ
Document Quarterly Report	true
Document Transition Report	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 130,849	$ 226,748
Marketable securities	560,219	685,475
Accounts receivable	12,329	36,456
Prepaid expenses and other current assets	53,814	49,651
Total current assets	757,211	998,330
Marketable securities - noncurrent	248,805	99,864
Property and equipment, net	30,273	32,760
Operating lease right-of-use assets	105,412	115,375
Equity method investment	0	11,765
Investments and other assets	49,835	42,883
Total assets	1,191,536	1,300,977
Current liabilities:
Accounts payable	18,816	7,452
Accrued expenses	45,127	67,017
Current portion of operating lease liability	18,963	18,599
Current portion of deferred revenue	22,184	22,140
Total current liabilities	105,090	115,208
Deferred revenue, net of current portion	28,052	38,853
Long-term operating lease liability	87,332	96,747
Total liabilities	220,474	250,808
Commitments and contingencies (Note 6)
Stockholders' equity:
Common stock, $0.0001 par value; 240,000,000 shares authorized at June 30, 2024 and December 31, 2023; 98,289,150 and 92,997,158 shares issued and outstanding at June 30, 2024 and December 31, 2023, respectively	10	9
Additional paid-in capital	2,884,997	2,710,797
Accumulated other comprehensive loss	(1,155)	(2,258)
Accumulated deficit	(1,912,790)	(1,658,379)
Total stockholders’ equity	971,062	1,050,169
Total liabilities and stockholders' equity	$ 1,191,536	$ 1,300,977

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Jun. 30, 2024	Dec. 31, 2023
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	240,000,000	240,000,000
Common stock, shares issued	98,289,150	92,997,158
Common stock, shares outstanding	98,289,150	92,997,158

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Income Statement [Abstract]
Collaboration revenue	$ 6,957	$ 13,594	$ 35,892	$ 26,200
Type of Revenue [Extensible List]	us-gaap:LicenseAndServiceMember	us-gaap:LicenseAndServiceMember	us-gaap:LicenseAndServiceMember	us-gaap:LicenseAndServiceMember
Operating expenses:
Research and development	$ 114,207	$ 115,276	$ 226,054	$ 212,392
General and administrative	31,793	30,652	62,884	58,100
Total operating expenses	146,000	145,928	288,938	270,492
Operating loss	(139,043)	(132,334)	(253,046)	(244,292)
Other (expense) income, net:
Interest income	12,422	12,653	25,054	24,633
Change in fair value of investments, net	(20,354)	0	(26,419)	0
Loss from equity method investment	0	(4,000)	0	(7,048)
Change in fair value of contingent consideration	0	0	0	(100)
Total other (expense) income , net	(7,932)	8,653	(1,365)	17,485
Net loss	$ (146,975)	$ (123,681)	$ (254,411)	$ (226,807)
Net loss per share, basic	$ (1.52)	$ (1.4)	$ (2.64)	$ (2.58)
Net loss per share, diluted	$ (1.52)	$ (1.4)	$ (2.64)	$ (2.58)
Weighted average shares outstanding, basic	96,975	88,185	96,238	87,979
Weighted average shares outstanding, diluted	96,975	88,185	96,238	87,979
Other comprehensive (loss) gain:
Unrealized (loss) gain on marketable securities	$ (208)	$ (1,482)	$ (1,029)	$ 1,507
Other comprehensive gain - equity method investment	0	292	0	2,086
Comprehensive loss	$ (147,183)	$ (124,871)	$ (255,440)	$ (223,214)

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	At The Market Offerings [Member]	Common Stock	Common Stock At The Market Offerings [Member]	Additional Paid-In Capital	Additional Paid-In Capital At The Market Offerings [Member]	Accumulated Other Comprehensive Income	Retained Earnings
Beginning balance at Dec. 31, 2022	$ 1,235,584		$ 9		$ 2,420,223		$ (7,461)	$ (1,177,187)
Beginning balance, shares at Dec. 31, 2022			87,103,007
Issuance of common stock		$ 1,466				$ 1,466
Issuance of common stock, shares				35,349
Contingent consideration paid, shares			567,045
Contingent consideration paid	24,126				24,126
Exercise of stock options	755				755
Exercise of stock options, shares			48,353
Vesting of restricted stock units, shares			342,025
Stock-based compensation	27,255				27,255
Other comprehensive gain (loss) - unrealized gain (loss) on marketable securities	2,989						2,989
Other comprehensive gain (loss) - equity method investment	1,794						1,794
Net Income (Loss)	(103,126)							(103,126)
Ending balance at Mar. 31, 2023	1,190,843		$ 9		2,473,825		(2,678)	(1,280,313)
Ending balance, shares at Mar. 31, 2023			88,095,779
Beginning balance at Dec. 31, 2022	1,235,584		$ 9		2,420,223		(7,461)	(1,177,187)
Beginning balance, shares at Dec. 31, 2022			87,103,007
Other comprehensive gain (loss) - equity method investment	2,086
Net Income (Loss)	(226,807)
Ending balance at Jun. 30, 2023	1,104,888		$ 9		2,512,741		(3,868)	(1,403,994)
Ending balance, shares at Jun. 30, 2023			88,347,634
Beginning balance at Mar. 31, 2023	1,190,843		$ 9		2,473,825		(2,678)	(1,280,313)
Beginning balance, shares at Mar. 31, 2023			88,095,779
Exercise of stock options	465				465
Exercise of stock options, shares			30,371
Vesting of restricted stock units, shares			151,853
Issuance of shares under employee stock purchase plan	2,051				2,051
Issuance of shares under employee stock purchase plan, shares			69,631
Stock-based compensation	36,400				36,400
Other comprehensive gain (loss) - unrealized gain (loss) on marketable securities	(1,482)						(1,482)
Other comprehensive gain (loss) - equity method investment	292						292
Net Income (Loss)	(123,681)							(123,681)
Ending balance at Jun. 30, 2023	1,104,888		$ 9		2,512,741		(3,868)	(1,403,994)
Ending balance, shares at Jun. 30, 2023			88,347,634
Beginning balance at Dec. 31, 2023	$ 1,050,169		$ 9		2,710,797		(2,258)	(1,658,379)
Beginning balance, shares at Dec. 31, 2023	92,997,158		92,997,158
Issuance of common stock		55,959		$ 1		55,958
Issuance of common stock, shares				2,209,938
Exercise of stock options	$ 1,958				1,958
Exercise of stock options, shares			110,734
Vesting of restricted stock units, shares			1,015,543
Stock-based compensation	34,176				34,176
Other comprehensive gain (loss) - unrealized gain (loss) on marketable securities	(821)						(821)
Reclassification of other comprehensive loss - equity method investment	2,132						2,132
Net Income (Loss)	(107,436)							(107,436)
Ending balance at Mar. 31, 2024	1,036,137		$ 10		2,802,889		(947)	(1,765,815)
Ending balance, shares at Mar. 31, 2024			96,333,373
Beginning balance at Dec. 31, 2023	$ 1,050,169		$ 9		2,710,797		(2,258)	(1,658,379)
Beginning balance, shares at Dec. 31, 2023	92,997,158		92,997,158
Exercise of stock options, shares	190,246
Other comprehensive gain (loss) - equity method investment	$ 0
Net Income (Loss)	(254,411)
Ending balance at Jun. 30, 2024	$ 971,062		$ 10		2,884,997		(1,155)	(1,912,790)
Ending balance, shares at Jun. 30, 2024	98,289,150		98,289,150
Beginning balance at Mar. 31, 2024	$ 1,036,137		$ 10		2,802,889		(947)	(1,765,815)
Beginning balance, shares at Mar. 31, 2024			96,333,373
Issuance of common stock		$ 38,399				$ 38,399
Issuance of common stock, shares				1,592,823
Exercise of stock options	1,179				1,179
Exercise of stock options, shares			79,512
Vesting of restricted stock units, shares			195,691
Issuance of shares under employee stock purchase plan	1,669				1,669
Issuance of shares under employee stock purchase plan, shares			87,751
Stock-based compensation	40,861				40,861
Other comprehensive gain (loss) - unrealized gain (loss) on marketable securities	(208)						(208)
Other comprehensive gain (loss) - equity method investment	0
Net Income (Loss)	(146,975)							(146,975)
Ending balance at Jun. 30, 2024	$ 971,062		$ 10		$ 2,884,997		$ (1,155)	$ (1,912,790)
Ending balance, shares at Jun. 30, 2024	98,289,150		98,289,150

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Mar. 31, 2023
At The Market Offerings [Member]
Stock issuance cost, net	$ 14	$ 210	$ 62

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss			$ (254,411)	$ (226,807)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization			5,111	4,220
Loss on disposal of property and equipment			0	15
Stock-based compensation			75,037	63,655
Accretion of investment discounts and premiums			(9,934)	(11,667)
(Recognition) deferral of equity method investment intra-entity profit on sales			(20,967)	5,656
Change in fair value of investments	$ 20,354	$ 0	26,419	0
Loss from equity method investment	0	4,000	0	7,048
Change in fair value of contingent consideration	0	0	0	100
Changes in operating assets and liabilities:
Accounts receivable			24,128	(1,289)
Prepaid expenses and other current assets			(6,239)	(6,078)
Operating lease right-of-use assets			9,963	9,373
Other assets			1,493	(503)
Accounts payable			10,916	6,287
Accrued expenses			(20,555)	(12,525)
Deferred revenue			(10,757)	(28,919)
Operating lease liabilities			(9,052)	(8,217)
Net cash used in operating activities			(178,848)	(199,651)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment			(3,518)	(8,133)
Purchases of marketable securities			(560,368)	(625,319)
Sales and maturities of marketable securities			545,597	476,666
Net cash used in investing activities			(18,289)	(156,786)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from options exercised			3,137	1,220
Issuance of shares through employee stock purchase plan			1,669	2,051
Net cash provided by financing activities			101,238	4,737
Net decrease in cash, cash equivalents and restricted cash equivalents			(95,899)	(351,700)
Cash, cash equivalents and restricted cash equivalents, beginning of period			240,353	535,463
Cash, cash equivalents and restricted cash equivalents, end of period	144,454	183,763	144,454	183,763
Reconciliation of cash, cash equivalents and restricted cash equivalents to condensed consolidated balance sheet:
Cash and cash equivalents	130,849	171,806	130,849	171,806
Restricted cash equivalents, included in investments and other assets	13,605	11,957	13,605	11,957
Total cash, cash equivalents and restricted cash equivalents	144,454	183,763	144,454	183,763
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Purchases of property and equipment unpaid at period end			631	2,998
Shares issued for Rewrite contingent consideration	$ 0	$ 24,126	0	24,126
At The Market Offerings [Member]
CASH FLOWS FROM FINANCING ACTIVITIES:
Net proceeds from issuance of common stock through at-the-market offerings			$ 96,432	$ 1,466

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2024	Jun. 30, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ (146,975)	$ (107,436)	$ (123,681)	$ (103,126)	$ (254,411)	$ (226,807)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Jun. 30, 2024
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	Rule 10b5-1 Trading Plans The following table describes for the three months ended June 30, 2024 each trading arrangement under which the Company’s directors or officers adopted, materially modified , or terminated any contract, instruction, or written plan for the purchase or sale of Company securities that was intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) or any non-Rule 10b5-1 trading arrangement. Name (Title) Action Taken (Date of Action) Type of Trading Arrangement Nature of Trading Arrangement Duration of Trading Arrangement Aggregate Number of Securities Michael P . Dube (VP, Chief Accounting Officer) Adoption ( June 27, 2024 ) Rule 10b5-1 trading arrangement Sale Until the earlier of (a) June 27, 2025 ; (b) the first date on which all trades have been executed or expired without execution; and (c) the date on which the plan holder gives notice to terminate the plan. Indeterminable (1) The number of shares that will be sold in accordance with this trading arrangement is indeterminable at the time of the filing of this Quarterly Report on Form 10-Q for the period ended June 30, 2024. Upon vesting of RSUs, it is the Company’s policy to immediately initiate a sell-to-cover in order to satisfy any applicable tax withholding obligations on behalf of the employee. The number of shares sold in the sell-to-cover will vary based on the market price of the Company’s common stock at the time of settlement. Any remaining shares held by Mr. Dube after the sell-to-cover may be sold pursuant to the terms of this trading arrangement.
Rule 10b5-1 Arrangement Modified	true
Michael Dube [Member]
Trading Arrangements, by Individual
Name	Michael P
Title	Dube (VP, Chief Accounting
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	June 27, 2024
Rule 10b5-1 Arrangement Terminated	true
Termination Date	June 27, 2025
Expiration Date	June 27, 2025
Arrangement Duration	1 year

Overview and Basis of Presentat

Overview and Basis of Presentation	6 Months Ended
	Jun. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Overview and Basis of Presentation	1. Overview and Basis of Presentation Intellia Therapeutics, Inc. (“Intellia” or the “Company”) is a leading clinical-stage gene editing company, focused on developing potentially curative therapeutics using CRISPR/Cas9-based technologies. CRISPR/Cas9, an acronym for C lustered, R egularly I nterspaced S hort P alindromic R epeats (“CRISPR”)/CRISPR associated 9 (“Cas9”), is a technology for genome editing, the process of altering selected sequences of genomic deoxyribonucleic acid (“DNA”). To fully realize the transformative potential of CRISPR/Cas9-based technologies, Intellia is building a full-spectrum gene editing company, by leveraging its modular platform, to advance in vivo and ex vivo therapies for diseases with high unmet need by pursuing two primary approaches. For in vivo applications to address genetic diseases, the Company deploys CRISPR/Cas9 as the therapy. The Company’s in vivo programs use CRISPR to enable precise editing of disease-causing genes directly inside the human body. In addition, the Company is advancing ex vivo applications to address immuno-oncology and autoimmune diseases, where it uses CRISPR/Cas9 as the tool to create the engineered cell therapy. For its ex vivo programs, CRISPR/Cas9 is used to engineer human cells outside the body. The Company’s deep scientific, technical and clinical development experience, along with its robust intellectual property (“IP”) portfolio, have enabled it to unlock broad therapeutic applications of CRISPR/Cas9 and related technologies to create new classes of genetic medicine. The condensed consolidated financial statements of the Company included herein have been prepared, without audit, pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Certain information and footnote disclosures normally included in annual financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) have been condensed or omitted from this report, as is permitted by such rules and regulations. Accordingly, these condensed consolidated financial statements should be read in conjunction with the financial statements and notes thereto included in the Company’s Annual Report on Form 10-K (“Annual Report”) for the year ended December 31, 2023. The unaudited condensed consolidated financial statements include the accounts of Intellia Therapeutics, Inc. and its wholly- owned subsidiary, Intellia Securities Corp. All intercompany balances and transactions have been eliminated in consolidation. Comprehensive loss is comprised of net loss, unrealized gain/loss on marketable securities and other comprehensive gain/loss from equity method investment. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates, judgments and assumptions that affect the amounts reported in the financial statements and accompanying notes. Significant estimates in these condensed consolidated financial statements have been made in connection with the calculation of revenues, research and development expenses, valuation of equity and fair value method investments, contingent consideration and stock-based compensation expense. The Company bases its estimates on historical experience and various other assumptions that management believes to be reasonable under the circumstances at the time such estimates are made. Actual results could differ from those estimates. The Company periodically reviews its estimates in light of changes in circumstances, facts and experience. The effects of material revisions in estimates, if any, would be reflected in the condensed consolidated financial statements prospectively from the date of the change in estimate. In the opinion of management, the information furnished reflects all adjustments, all of which are of a normal and recurring nature, necessary for a fair presentation of the results for the reported interim periods. The Company considers events or transactions that occur after the balance sheet date but before the financial statements are issued to provide additional evidence relative to certain estimates or to identify matters that require additional disclosure. The results of operations for interim periods are not necessarily indicative of results to be expected for the full year or any other interim period. Liquidity Since its inception through June 30, 2024 , the Company has raised an aggregate of $ 2,666.7 million to fund its operations through its initial public offering (“IPO”) and concurrent private placements, follow-on public offerings, at-the-market offerings and the sale of convertible preferred stock, as well as through its collaboration agreements. The Company expects that its cash, cash equivalents and marketable securities as of June 30, 2024 will enable the Company to fund its ongoing operating expenses and capital expenditure requirements for at least the twelve-month period following the issuance of these condensed consolidated financial statements.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2024
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies The Company’s significant accounting policies are described in Note 2, “Summary of Significant Accounting Policies” to the consolidated financial statements included in the Annual Report for the year ended December 31, 2023. There have been no material changes to these policies during the six months ended June 30, 2024. Recent Issued Accounting Pronouncements Not Yet Effective In November 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2023-07, Segment Reporting - Improvements to Reportable Segment Disclosures. The ASU requires disclosure of incremental segment information on an annual and interim basis and also requires companies with a single reportable segment to provide all disclosures required by this ASU and all existing segment disclosures in Accounting Standard Codification (“ASC”) 280, Segment Reporting . The ASU is effective for fiscal years beginning after December 15, 2023, and interim periods beginning after December 15, 2024. The Company is currently evaluating the impact of adopting this ASU on its consolidated financial statements and disclosures. In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures . This ASU updates income tax disclosure requirements primarily by requiring specific categories and greater disaggregation within the rate reconciliation and disaggregation of income taxes paid by jurisdiction. This ASU is effective for annual periods beginning after December 15, 2024 and is applicable to the Company’s fiscal year beginning January 1, 2025, with early application permitted. The Company is currently evaluating the impact of adopting this ASU on its consolidated financial statements and disclosures.

Marketable Securities

Marketable Securities	6 Months Ended
	Jun. 30, 2024
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	3. Marketable Securities The following table summarizes the Company’s available-for-sale marketable securities: June 30, 2024 Amortized Gross Unrealized Gross Unrealized Estimated Fair (In thousands) Marketable securities: U.S. Treasury and other government-backed securities $ 439,731 $ 69 $ ( 727 ) $ 439,073 Financial institution debt securities 228,035 58 ( 381 ) 227,712 Corporate debt securities 105,597 5 ( 125 ) 105,477 Other asset-backed securities 36,815 - ( 53 ) 36,762 Total $ 810,178 $ 132 $ ( 1,286 ) $ 809,024 December 31, 2023 Amortized Gross Unrealized Gross Unrealized Estimated Fair (In thousands) Marketable securities: U.S. Treasury and other government-backed securities $ 382,260 $ 302 $ ( 254 ) $ 382,308 Financial institution debt securities 246,270 92 ( 243 ) 246,119 Corporate debt securities 97,490 53 ( 135 ) 97,408 Other asset-backed securities 59,453 75 ( 24 ) 59,504 Total $ 785,473 $ 522 $ ( 656 ) $ 785,339 The amortized cost of available-for-sale securities is adjusted for amortization of premiums and accretion of discounts to maturity. There were no material realized gains or losses in the six months ended June 30, 2024 or for the year ended December 31, 2023. The Company generally does not intend to sell any investments prior to recovery of their amortized cost basis for any investment in an unrealized loss position. As such, the Company has classified these losses as temporary in nature. The Company’s available-for-sale securities that are classified as short-term marketable securities in the condensed consolidated balance sheet mature within one year or less as of the balance sheet date. Available-for-sale securities that are classified as noncurrent in the condensed consolidated balance sheet are those that mature after one year but within five years from the balance sheet date and that the Company does not intend to dispose of within the next twelve months. At June 30, 2024 and December 31, 2023, the Company did no t hold any marketable securities that matured beyond five years of the balance sheet date.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2024
Fair Value Disclosures [Abstract]
Fair Value Measurements	4. Fair Value Measurements The Company classifies fair value-based measurements using a three-level hierarchy that prioritizes the inputs used to measure fair value. This hierarchy requires entities to maximize the use of observable inputs and minimize the use of unobservable inputs. The three levels of inputs used to measure fair value are as follows: Level 1, quoted market prices (unadjusted) in active markets for identical assets or liabilities; Level 2, observable inputs other than quoted market prices included in Level 1, such as quoted market prices for markets that are not active or other inputs that are observable or can be corroborated by observable market data; and Level 3, unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities, including certain pricing models, discounted cash flow methodologies and similar techniques that use significant unobservable inputs. The Company’s financial assets recognized at fair value on a recurring basis consisted of the following: June 30, 2024 Total Level 1 Level 2 Level 3 (In thousands) Assets Cash equivalents and restricted cash equivalents $ 103,947 $ 103,947 $ - $ - Marketable securities: U.S. Treasury and other government-backed securities 439,073 203,649 235,424 - Financial institution debt securities 227,712 - 227,712 - Corporate debt securities 105,477 - 105,477 - Other asset-backed securities 36,762 - 36,762 - Total marketable securities 809,024 203,649 605,375 - Investment in Kyverna Therapeutics, Inc. 8,804 8,804 - - Total assets $ 921,775 $ 316,400 $ 605,375 $ - December 31, 2023 Total Level 1 Level 2 Level 3 (In thousands) Assets Cash equivalents and restricted cash equivalents $ 136,254 $ 136,254 $ - $ - Marketable securities: U.S. Treasury and other government-backed securities 382,308 120,556 261,752 - Financial institution debt securities 246,119 - 246,119 - Corporate debt securities 97,408 - 97,408 - Other asset-backed securities 59,504 - 59,504 - Total marketable securities 785,339 120,556 664,783 - Total assets $ 921,593 $ 256,810 $ 664,783 $ - Certain of the Company’s financial assets, including cash equivalents, restricted cash equivalents and marketable securities, have been initially valued at the transaction price, and subsequently revalued at the end of each reporting period, utilizing third party pricing services or other observable market data. The pricing services utilize industry standard valuation models and observable market inputs to determine value. Other financial instruments, including accounts receivable, accounts payable and accrued expense, are carried at cost, which approximates fair value due to the short duration and term to maturity. The Company has determined that the estimated fair value of its investment in Kyverna Therapeutics, Inc. (“Kyverna”), a publicly traded company, is reported as Level 1 as it is valued at a quoted market price in an active market. The investment in Kyverna is classified within “investments and other assets” in the condensed consolidated balance sheets. Refer to Note 8 for further details. Other Investments The Company’s other investments include investments in AvenCell Therapeutics, Inc. (“AvenCell”) and SparingVision Sas (“SparingVision”). These investments are accounted for under ASC 321, Investments in Equity Securities (“ASC 321”) using the measurement alternative at cost minus impairment with adjustments for changes in observable prices . The Company previously accounted for the AvenCell investment under the equity method; refer to Note 8 for further details. The Company monitors any events or changes in circumstances that may have a significant effect on the fair value of investments, either due to impairment or based on observable price changes, and records adjustments as needed. These investments are classified as Level 3 assets and are not included in the fair value table above as they are not valued at fair value on a recurring basis.

Accrued Expenses

Accrued Expenses	6 Months Ended
	Jun. 30, 2024
Payables and Accruals [Abstract]
Accrued Expenses	5. Accrued Expenses Accrued expenses consisted of the following: June 30, December 31, 2024 2023 (In thousands) Accrued research and development $ 21,961 $ 27,411 Employee compensation and benefits 14,901 26,615 Accrued legal and professional expenses 3,633 2,063 Accrued construction costs 2,327 6,891 Accrued other 2,305 4,037 Total accrued expenses $ 45,127 $ 67,017

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	6. Commitments and Contingencies Litigation From time to time, the Company may be involved in legal and administrative proceedings and claims of various types. In some actions, the claimants seek damages, as well as other relief, which, if granted, would require significant expenditures. The Company records a liability in its consolidated financial statements for these matters when a loss is known or considered probable and the amount can be reasonably estimated. The Company reviews these estimates each accounting period as additional information is known and adjusts the loss provision when appropriate. If a matter is both probable to result in a liability to the Company and the amount of the loss can be reasonably estimated, the Company estimates and discloses the possible loss or range of loss. If the loss is not probable or cannot be reasonably estimated, a liability is not recorded in its consolidated financial statements. BlueAllele Corp. v. Intellia Therapeutics, Inc. On July 8, 2024, BlueAllele Corp. (“BlueAllele”) filed a complaint alleging infringement by the Company of various patents in the U.S. District Court for the District of Delaware. Specifically, BlueAllele alleges that the Company’s experimentation, basic research, identification, optimization, manufacturing and/or use of bi-directional insertion template technology infringes the asserted patents and seeks unspecified compensatory damages and an injunction against the alleged infringing activities. Intellia intends to defend itself in this matter. At this stage, the Company is unable to determine the likelihood of an unfavorable outcome or estimate the amount or range of potential loss, if any. Except as noted above, there have been no material changes to any outstanding litigation, nor is the Company a party to any material new litigation, since December 31, 2023. License Agreements The Company is party to license agreements, which may include contingent payments. These payments will become payable if and when certain development, regulatory and commercial milestones are achieved. As of June 30, 2024 , the satisfaction and timing of the contingent payments is uncertain and not reasonably estimable.

Collaborations and Other Arrang

Collaborations and Other Arrangements	6 Months Ended
	Jun. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Collaborations and Other Arrangements	7. Collaborations and Other Arrangements To accelerate the development and commercialization of CRISPR/Cas9-based products in multiple therapeutic areas, the Company has formed, and intends to seek other opportunities to form, strategic alliances with collaborators who can augment its leadership in CRISPR/Cas9 therapeutic development. As of June 30, 2024, the Company’s accounts receivable were related to its collaborations with Regeneron Pharmaceuticals, Inc. (“Regeneron”), SparingVision and AvenCell, and the Company’s contract liabilities were related to its collaborations with Regeneron and SparingVision. As of December 31, 2023, the Company’s accounts receivable were related to its collaborations with Regeneron, SparingVision, AvenCell and Kyverna and the Company’s contract liabilities were related to its collaborations with Regeneron and SparingVision. The following table presents changes in the Company’s accounts receivable and contract liabilities (in thousands): Balance at Additions Deductions Balance at End Six months ended June 30, 2024 Accounts receivable $ 36,456 $ 11,809 $ ( 35,936 ) $ 12,329 Contract liabilities - deferred revenue $ 60,993 $ - $ ( 10,757 ) $ 50,236 Balance at Additions Deductions Balance at End Six months ended June 30, 2023 Accounts receivable $ 3,768 $ 9,305 $ ( 8,017 ) $ 5,056 Contract liabilities - deferred revenue $ 63,771 $ - $ ( 28,919 ) $ 34,852 During the six months ended June 30, 2024 and 2023, the Company recognized the following revenues as a result of changes in the contract liability balance (in thousands): Six Months Ended June 30, Revenue recognized in the period from: 2024 2023 Amounts included in the contract liability at the beginning of the period $ 10,757 $ 23,273 The Company has not incurred significant expenses to obtain collaboration agreements and costs to fulfill those contracts do not generate or enhance resources of the Company. As such, no costs to obtain or fulfill a contract have been capitalized in any period. Regeneron Pharmaceuticals, Inc. In April 2016, the Company entered into a license and collaboration agreement with Regeneron (as amended from time to time, the “2016 Regeneron Agreement”). In October 2023, Regeneron exercised its one-time option to extend the technology collaboration term for an additional two years , until April 2026 , in exchange for a nonrefundable payment of $ 30.0 million, which was received by the Company in April 2024. In September 2023, Regeneron and Intellia further expanded the research collaboration (the “2023 Regeneron Amendment”) to develop additional in vivo CRISPR-based gene editing therapies focused on neurological and muscular diseases. In 2018, the Company entered into a co-development and co-promotion (“Co/Co”) agreement with Regeneron for transthyretin (“ATTR”) amyloidosis (the “ATTR Co/Co”). In May 2020, the Company entered into co-development and co-funding agreements for the treatment of hemophilia A and hemophilia B (the “Hemophilia Co/Co”) agreements. In March 2024, the Company notified Regeneron that it is opting out of its hemophilia B Co/Co agreement. The Company will continue to have obligations under the hemophilia B Co/Co agreement until September 2024. In addition, after termination of the hemophilia B Co/Co agreement the Company will continue to support Regeneron with the development of gene editing products directed to hemophilia B, as applicable, under the 2016 Regeneron Agreement. That agreement will control the parties’ obligations to develop and commercialize gene editing products directed to hemophilia B. The Company may be eligible to receive up to $ 320.0 million in milestone payments and royalties in the high-single digits to low teens, which royalties are potentially subject to various reductions, offsets and upstream payment obligations. Since December 31, 2023, there have been no material changes to the key terms of the 2016 Regeneron Agreement, ATTR Co/Co, Hemophilia Co/Co, or 2023 Regeneron Amendment (the “Regeneron Agreements”), other than as described above. The Company recognized collaboration revenue related to the Regeneron Agreements of $ 6.4 million and $ 13.8 million during the three and six months ended June 30, 2024, respectively, and $ 7.3 million and $ 14.1 million during the three and six months ended June 30, 2023, respectively, in the condensed consolidated statements of operations and comprehensive loss. This includes approximately $ 5.1 million and $ 9.7 million during the three and six months ended June 30, 2024, respectively, and $ 4.5 million and $ 8.7 million during the three and six months ended June 30, 2023, respectively, primarily representing payments due from Regeneron pursuant to the ATTR Co/Co. These revenues are offset in part by contra-revenue related to the Hemophilia Co/Co agreements amounting to approximately $ 4.4 million and $ 7.6 million during the three and six months ended June 30, 2024, respectively, and $ 2.8 million and $ 5.8 million during the three and six months ended June 30, 2023, respectively . As of June 30, 2024 , there was $ 36.8 million of the aggregate transaction price remaining to be recognized through April 2026, the remaining period of the 2016 Regeneron Agreement . As of June 30, 2024 and December 31, 2023 , the Company had accounts receivable of $ 11.5 million and $ 35.7 million, respectively, and deferred revenue of $ 36.8 million and $ 47.1 million, respectively, related to the Regeneron Agreements. SparingVision SAS In October 2021, the Company and SparingVision, a genomic medicine company developing vision saving treatments for ocular diseases, entered into a license and collaboration agreement (the “SparingVision LCA”) to develop novel genomic medicines utilizing CRISPR/Cas9 technology for the treatment of ocular diseases. Since December 31, 2023, there have been no material changes to the key terms of the SparingVision LCA agreement. The Company recognized collaboration revenue related to the SparingVision LCA of approximately $ 0.5 million and $ 1.1 million, respectively, for the three and six months ended June 30, 2024 and $ 0.5 million and $ 0.9 million, respectively, for the three and six months ended June 30, 2023, in the condensed consolidated statements of operations and comprehensive loss. As of June 30, 2024 and December 31, 2023 , the Company had $ 0.6 million and $ 0.5 million in accounts receivable, respectively, related to the SparingVision LCA. As of June 30, 2024 and December 31, 2023 , the Company had deferred revenue of $ 13.4 million and $ 13.9 million, respectively, related to the SparingVision LCA, which is expected to be recognized over a six to nine year period from the signing of the agreement. ReCode Therapeutics, Inc. (“ReCode”) On February 14, 2024, the Company entered into a license, collaboration and option agreement with ReCode (the “ReCode LCA”), a clinical-stage genetic medicines company, to develop novel genomic medicines for the treatment of cystic fibrosis (“CF”). The ReCode LCA leverages the Company’s proprietary CRISPR-based gene editing platform, including its DNA writing technology, and ReCode’s proprietary Selective Organ Targeting (“SORT”) lipid nanoparticle delivery platform to precisely correct one or more CF disease-causing gene mutations. As part of the agreement, the companies will focus initial research efforts on therapeutic approaches that address CF for patients who have limited or no treatment options available, with the opportunity to expand the scope of the collaboration in later phases. The Company will be responsible for the design of the editing strategy and research-grade components for the investigational therapies. ReCode will lead the subsequent preclinical and clinical development and worldwide commercialization for certain programs arising from the collaboration. The Company also has an option to lead commercialization in the U.S. for certain programs (the “Co/Co option”). The ReCode LCA did not include an exchange of upfront consideration between the parties. The Company will be eligible to receive pre-specified development and commercial milestone payments, up to $ 262.0 million per product, as well as single digit royalties on potential sales. Certain milestone and royalty payments may be removed or reduced for a product if the Company exercises the Co/Co option. The Company did not recognize any revenue from the ReCode LCA during the three or six months ended June 30, 2024. Other Agreements The Company has existing license and collaboration agreements with AvenCell, Kyverna, and ONK Therapeutics, Ltd (“ONK”) . Since December 31, 2023, there have been no material changes to the key terms of the AvenCell, Kyverna and ONK license and collaboration agreements. During the six months ended June 30, 2024, the Company recognized $ 21.0 million of previously eliminated intra-entity profit related to the AvenCell license and collaboration agreement (the “AvenCell LCA”) in the condensed consolidated statements of operations and comprehensive loss. See Note 8 for further details. The Company did no t recognize material revenue from the Kyverna and ONK agreements during the three or six month periods ending June 30, 2024. During the three months ended June 30, 2023, the Company recognized $ 5.8 million in revenue related to AvenCell and did no t recognize revenue related to Kyverna or ONK during that period. During the six months ended June 30, 2023, the Company recognized $ 10.7 million, $ 0.4 million and $ 0.1 million in revenue related to AvenCell, Kyverna and ONK, respectively.

Investments and Other Assets

Investments and Other Assets	6 Months Ended
	Jun. 30, 2024
Investments, All Other Investments [Abstract]
Investments and Other Assets	8. Investments and Other Assets Investments and other assets consisted of the following: June 30, December 31, 2024 2023 (In thousands) Investment in Kyverna $ 8,804 $ 10,000 Other investments 24,213 14,760 Restricted cash equivalents, long-term 13,605 13,605 Prepaid expenses and other assets, long-term 3,213 4,518 Total investments and other assets $ 49,835 $ 42,883 Kyverna Therapeutics, Inc. In February 2024, Kyverna completed an initial public offering of its common stock (the “Kyverna IPO”). Prior to the Kyverna IPO, the Company accounted for its investment in Kyverna using the measurement alternative as Kyverna was a private company with no readily observable transaction price, and the investment was valued at $ 10.0 million as of December 31, 2023. As of June 30, 2024, the Company’s investment in Kyverna is valued at $8 .8 million. The Company recognized an unrealized loss of $ 20.4 million and $ 1.2 million, recorded within “change in fair value of investments, net” in the condensed consolidated statement of operations and comprehensive loss during the three and six months ended June 30, 2024, respectively, associated with changes in the fair value of Kyverna’s common stock. AvenCell Therapeutics, Inc. As of June 30, 2024 and December 31, 2023, the Company holds a 33.33 % equity interest in AvenCell. As of December 31, 2023, the Company accounted for its investment using the equity method of accounting, as the Company had significant influence, but not control, over AvenCell, and the investment was valued at $ 11.8 million. During the first quarter of 2024, in conjunction with the completion of a debt financing, AvenCell increased the size of their board, with a single investor having control over AvenCell’s operational and financial decisions. As a result, the Company no longer has the ability to exercise significant influence over AvenCell, and therefore the Company’s investment in AvenCell is accounted for in accordance with ASC 321 as of June 30, 2024, and AvenCell is no longer considered to be a related party. The transition from equity method accounting to ASC 321 required the Company to reclassify $ 2.1 million from accumulated other comprehensive loss amounts previously recognized as a result of the investment in AvenCell to the carrying value of the investment in AvenCell and recognize $ 21.0 million of previously eliminated intra-entity profit as “collaboration revenue” in the condensed consolidated statement of operations and comprehensive loss during the first quarter of 2024. The Company also considered whether there was an indication that the investment was impaired, and recorded an impairment of $ 25.3 million within “change in fair value of investments, net” in the condensed consolidated statement of operations and comprehensive loss during that period. This impairment was caused by AvenCell’s financial condition, indicators of fair value based on the completion of the debt financing, and an executed term sheet for further financing, which indicated that the fair value of the investment was less than its carrying value. The Company used a market approach to value the investment, which is a Level 3 measurement in the fair value hierarchy. Other than the $ 21.0 million of previously eliminated intra-entity profit noted above that was recognized during the six months ended June 30, 2024, no revenue was recognized during that period related to the AvenCell LCA. During the three and six months ended June 30, 2023, the Company recognized $ 5.8 million and $ 10.7 million in revenue, respectively, related to the AvenCell LCA. The Company had $ 0.2 million in accounts receivable and $ 1.0 million in accrued expenses related to the AvenCell agreements as of both June 30, 2024 and December 31, 2023. As of June 30, 2024, the carrying value of the Company’s investment in AvenCell was $ 9.6 million. SparingVision SAS As of June 30, 2024, the fair value of the Company’s investment in SparingVision was $ 14.6 million. There have been no material changes in the valuation of the SparingVision investment as of June 30, 2024.

Leases

Leases	6 Months Ended
	Jun. 30, 2024
Leases [Abstract]
Leases	9. Leases The Company leases approximately 230,000 square feet of real estate, including laboratory and office space in Cambridge, Massachusetts and the surrounding areas. The Company’s leases have remaining terms ranging from one to approximately nine years. Certain leases include options to renew, exercised at the Company’s sole discretion, with varying renewal terms that can extend the lease term for an additional three to five years. All of the Company’s leases qualify as operating leases. Separately, the Company entered into an agreement in February 2022, later amended in June 2023, to lease approximately 140,000 square feet of office, general laboratory and planned good manufacturing practice (“GMP”) manufacturing space at 840 Winter Street in Waltham , Massachusetts (the “840 Winter Lease”). The Company anticipates a phased move-in process during the second half of 2024. As of June 30, 2024, the Company had not taken control of the premises and therefore there are no right of use assets or liabilities recorded related to the 840 Winter Lease under ASC 842, Leases (Topic 842) (“ASC 842”).

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2024
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	10. Stock-Based Compensation Stock-based compensation expense is classified in the condensed consolidated statements of operations and comprehensive loss as follows: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (In thousands) Research and development $ 25,439 $ 22,351 $ 45,600 $ 39,282 General and administrative 15,422 14,049 29,437 24,373 Total $ 40,861 $ 36,400 $ 75,037 $ 63,655 Stock Option and Incentive Plans In April 2016, the Company adopted the Amended and Restated 2015 Stock Option and Incentive Plan (the “2015 Plan”). The 2015 Plan provides for the grant of incentive stock options, non-qualified stock options, stock appreciation rights, restricted stock awards (“RSAs”), restricted stock units (“RSUs”) and other stock-based awards. Recipients of incentive stock options and non-qualified stock options are eligible to purchase shares of the Company’s common stock at an exercise price equal to the fair value of such stock on the grant date. As of June 30, 2024 , there were 4,614,029 shares available for future issuance under the 2015 Plan. The number of shares reserved for issuance under the 2015 Plan will be cumulatively increased on each January 1 st by four percent of the number of shares of stock issued and outstanding on the immediately preceding December 31 st or such lesser number of shares of stock as determined by the board of directors. In June 2024, the Company adopted the 2024 Inducement Plan (the “Inducement Plan”). The Inducement Plan provides for the grant of non-qualified stock options, stock appreciation rights, RSAs, RSUs, unrestricted stock awards and dividend equivalent rights to individuals who are not employed by the Company. Recipients of non-qualified stock options are eligible to purchase shares of the Company’s common stock at an exercise price equal to the fair value of such stock on the grant date. In accordance with the Inducement Plan, 850,000 shares of common stock have been reserved for future issuance. No grants had been made under the Inducement Plan as of June 30, 2024. Restricted Stock Units The following table summarizes the Company’s RSU activity for the six months ended June 30, 2024: Number of Weighted Unvested restricted stock units as of December 31, 2023 4,041,753 $ 50.40 Granted 3,042,554 34.20 Vested ( 1,211,234 ) 51.67 Cancelled ( 501,576 ) 44.28 Unvested restricted stock units as of June 30, 2024 5,371,497 $ 41.51 Restricted Stock Units - Service Awards The Company awards RSUs with a service condition to all employees upon hire and as part of their annual grant. RSUs with a service condition granted under the 2015 Plan in 2024 and 2023 generally vest as to one-third on the first anniversary of the original vesting date, with the balance vesting annually over the remaining two years. In March 2024, the Company granted 2,157,921 RSUs with a service condition to employees as part of their annual grant, which have the potential to vest over a period of three years . The weighted average grant date fair value of these RSUs was $ 32.66 and the vesting start date for these RSUs was January 1, 2024. In March 2023, the Company granted 2,195,135 RSUs with a service condition to employees as part of their annual grant, which have the potential to vest over a period of three years . The weighted average grant date fair value of these RSUs was $ 40.75 and the vesting start date for these RSUs was January 1, 2023. Unvested restricted stock units as of June 30, 2024 in the table above includes 4,478,007 RSUs that are service-based. Restricted Stock Units - Market Awards In March 2024, 2023 and 2022, market-based RSUs were granted to senior executives as part of their annual grant . These RSUs have the potential to vest after a period of three years , with a vesting start date of January 1, 2024, 2023 and 2022, respectively, and the number of shares to be delivered will depend on the Company ’s Total Shareholder Return (“TSR” ), a market condition, over that period relative to a defined group of biotechnology companies. The number of market-based RSUs granted in March 2024, 2023 and 2022 was 235,858 , 181,743 and 55,144 , respectively. The grant date fair value for the market-based RSUs, calculated using a Monte Carlo valuation model, was $ 51.12 , $ 68.55 and $ 126.49 , respectively. The following assumptions were used to determine the grant date fair value for the three years, respectively: risk free interest rate: 4.28 %, 4.60 % and 1.44 %; expected volatility: 77.2 %, 84.34 % and 82.53 %. The expected term for all grants was approximately 3.0 years; the expected dividend yield was 0.0 %. Unvested restricted stock units as of June 30, 2024 in the table above includes 438,329 RSUs that are market-based. Restricted Stock Units - Performance-Based Awards with TSR Multiplier Also in March 2024, 444,117 performance-based RSUs ( “PSUs”) with a relative TSR modifier were granted to senior executives as part of their annual grant . These PSUs, to the extent earned, shall vest on January 1, 2027, and the number of shares to be delivered will be determined based upon the achievement of certain performance goals, which can range from 0 % to 200 %. Following the determination of the achievement of performance criteria, the amount of shares awarded will be subject to adjustment based on the application of a TSR modifier, which can range from 75 % to 125 %. The grant date fair value for these PSUs, calculated using a Monte Carlo valuation model, was $ 36.16 . The following assumptions were used to determine the grant date fair value: risk free interest rate: 4.28 %; expected volatility: 77.2 %; expected term approximately 3.0 years; expected dividend yield: 0.0 %. The Company recognizes compensation expense ratably over the required service period based on its estimate of the number of shares that will vest based upon the probability of achieving the performance goals. Unvested restricted stock units as of June 30, 2024 in the table above includes 410,743 PSUs with a TSR multiplier. Restricted Stock Units - Performance-Based Awards In March 2022, the Company granted 66,296 performance-based RSUs to certain non-executive employees that would vest upon obtaining certain scientific milestones. There were two separate tranches, each attached to a different set of milestones. The milestone related to the first tranche, made up of 21,878 RSUs, was achieved in the first quarter of 2023 and these RSUs vested. The remaining performance milestones were considered not probable of achievement as of June 30, 2024 and, therefore, no related stock-based compensation was recorded during the period then ending. Unvested restricted stock units as of June 30, 2024 in the table above includes 44,418 performance-based RSUs. The weighted-average grant date fair value of all RSUs granted during the three and six months ended June 30, 2024 was $ 25.16 and $ 34.20 , respectively. The total fair value of RSUs vested (measured on the date of vesting) for the three and six months ended June 30, 2024 was $ 4.6 million and $ 35.5 million, respectively. The weighted-average grant date fair value of RSUs granted during the three and six months ended June 30, 2023 was $ 38.70 and $ 42.45 , respectively. The total fair value of RSUs vested (measured on the date of vesting) for the three and six months ended June 30, 2023 was $ 6.2 million and $ 18.3 million, respectively. As of June 30, 2024 , there was $ 156.1 million of unrecognized stock-based compensation expense related to all RSUs that are expected to vest. These costs are expected to be recognized over a weighted average remaining vesting period of 1.8 years . Stock Options The weighted average grant date fair value of options, estimated as of the grant date using the Black-Scholes option pricing model, was $ 17.50 and $ 22.01 per option for those options granted during the three and six months ended June 30, 2024, respectively, and $ 29.80 and $ 28.92 per option for those options granted during the three and six months ended June 30, 2023, respectively . Weighted average assumptions used to apply this pricing model were as follows: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 Risk-free interest rate 4.3 % 4.1 % 4.2 % 4.4 % Expected term 5.6 years 5.6 years 6.0 years 6.0 years Expected volatility of underlying stock 76.3 % 78.8 % 76.4 % 78.7 % Expected dividend yield 0.0 % 0.0 % 0.0 % 0.0 % Risk-free Interest Rate. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant with maturities approximately equal to the option’s expected term. Expected Term. The expected term represents the period that stock option awards are expected to be outstanding. For option grants that are considered to be “plain vanilla,” the Company determines the expected term using the simplified method. The simplified method deems the term to be the average of the time-to-vesting and the contractual life of the options. The Company uses the simplified method because it does not have sufficient historical option exercise data to provide a reasonable basis upon which to estimate the expected term. Expected Volatility. Expected volatility is estimated based on actual movements in the Company’s stock price over the most recent historical periods, over the expected term of their stock option grants. Expected Dividend Yield. The Company has not paid cash dividends and has no intention to pay cash dividends in the future. Stock options generally vest as to one-third on the first anniversary of the original vesting date, with the balance vesting monthly over the remaining two years, unless they contain specific vesting provisions. The maximum term of stock options granted under the 2015 Plan is ten years. The following is a summary of stock option activity for the six months ended June 30, 2024: Number of Weighted Weighted Aggregate (In years) (In thousands) Outstanding at December 31, 2023 5,458,999 $ 50.38 6.65 $ 35,922 Granted 772,191 31.86 Exercised ( 190,246 ) 16.49 Forfeited ( 331,773 ) 77.99 Outstanding at June 30, 2024 5,709,171 $ 47.40 6.30 $ 15,820 Exercisable at June 30, 2024 4,290,920 $ 45.38 5.51 $ 15,812 The total intrinsic value (the amount by which the fair market value exceeded the exercise price) of stock options exercised during the three and six months ended June 30, 2024 was $ 0.8 million and $ 2.0 million, respectively. The total intrinsic value of stock options exercised during the three and six months ended June 30, 2023 was $ 0.8 million and $ 1.9 million, respectively. As of June 30, 2024 , there was $ 43.5 million of unrecognized compensation cost related to stock options that have not yet vested which are expected to be recognized over a weighted average remaining vesting period of 1.22 years. Employee Stock Purchase Plan In May 2016, the Company adopted the 2016 Employee Stock Purchase Plan (the “2016 Plan”). The 2016 Plan allows eligible employees to purchase shares of the Company’s common stock on the last day of each predetermined six-month offering period at 85 % of the lower of the fair market value per share at the beginning or end of the applicable offering period. The 2016 Plan provides for six-month offering periods beginning in January and July of each year. As of June 30, 2024 , there were 989,736 shares available for future issuance under the 2016 Plan. The number of shares reserved for issuance under the 2016 Plan will be cumulatively increased on each January 1 st by the lesser of a) one percent of the number of shares of common stock issued and outstanding on the immediately preceding December 31 st , b) 500,000 shares of common stock, or c) such lesser number of shares of common stock as determined by the board of directors. During the six months ended June 30, 2024 and 2023 the Company issued 87,751 and 69,631 shares of common stock under the 2016 Plan, respectively. The weighted-average purchase prices of shares issued under the 2016 Plan were $ 19.02 and $ 29.45 per share for the six-month periods ended June 30, 2024 and 2023, respectively. The fair value of shares under the 2016 Plan was estimated at the beginning of the offering period using a Black-Scholes option-pricing model with the following assumptions: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 Risk-free interest rate 5.24 % 4.70 % 5.24 % 4.70 % Expected term 0.5 years 0.5 years 0.5 years 0.5 years Expected volatility of underlying stock 56.7 % 69.2 % 56.7 % 69.2 % Expected dividend yield 0.0 % 0.0 % 0.0 % 0.0 %

Loss Per Share

Loss Per Share	6 Months Ended
	Jun. 30, 2024
Earnings Per Share [Abstract]
Loss Per Share	11. Loss Per Share The Company calculates basic loss per share by dividing net loss for each respective period by the weighted average number of common shares outstanding for each respective period. The Company computes diluted loss per share after giving consideration to the dilutive effect of stock options and unvested restricted stock units that are outstanding during the period, except where such securities would be anti-dilutive. Basic and diluted loss per share was calculated as follows: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (In thousands) Net loss $ ( 146,975 ) $ ( 123,681 ) $ ( 254,411 ) $ ( 226,807 ) Weighted average shares outstanding, basic and diluted 96,975 88,185 96,238 87,979 Net loss per share, basic and diluted $ ( 1.52 ) $ ( 1.40 ) $ ( 2.64 ) $ ( 2.58 ) The following common stock equivalents were excluded from the calculation of diluted loss per share because their inclusion would have been anti-dilutive: Three and Six Months Ended June 30, 2024 2023 (In thousands) Unvested restricted stock units 5,371 4,087 Stock options 5,709 5,901 11,080 9,988

Stockholders_ Equity

Stockholders’ Equity	6 Months Ended
	Jun. 30, 2024
Equity [Abstract]
Stockholders’ Equity	12. Stockholders’ Equity At-the-Market Offering Programs 2022 Sale Agreement In March 2022, the Company entered into an Open Market Sale Agreement (the “2022 Sale Agreement”) with Jefferies LLC (“Jefferies”), under which Jefferies was able to offer and sell, from time to time in “at-the-market” offerings, shares of the Company’ s common stock having aggregate gross proceeds of up to $ 400.0 million. I n February 2024, the Company entered into an amendment to the 2022 Sale Agreement (the “2022 Sale Agreement, as amended”) to increase the size of the at-the-market offering program from $ 400.0 million to $ 750.0 million. The Company agreed to pay cash commissions of up to 3.0 % of the gross proceeds of sales of common stock under the 2022 Sale Agreement, as amended. Through June 30, 2024, the Company issued 11,320,924 shares of its common stock under the 2022 Sale Agreement, as amended. During the six months ended June 30, 2024 , the Company issued 3,802,761 shares of its common stock, in a series of sales, at an average price of $ 25.58 per share, in accordance with the 2022 Sale Agreement, as amended, for aggregate net proceeds of $ 94.4 million, after payment of cash commissions and approximately $ 0.2 million related to legal, accounting and other fees in connection with the sales. As of June 30, 2024 , $ 331.7 million in shares of common stock remain eligible for sale under the 2022 Sale Agreement, as amended.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2024
Accounting Policies [Abstract]
Recent Accounting Pronouncements - Adopted	Recent Issued Accounting Pronouncements Not Yet Effective In November 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2023-07, Segment Reporting - Improvements to Reportable Segment Disclosures. The ASU requires disclosure of incremental segment information on an annual and interim basis and also requires companies with a single reportable segment to provide all disclosures required by this ASU and all existing segment disclosures in Accounting Standard Codification (“ASC”) 280, Segment Reporting . The ASU is effective for fiscal years beginning after December 15, 2023, and interim periods beginning after December 15, 2024. The Company is currently evaluating the impact of adopting this ASU on its consolidated financial statements and disclosures. In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures . This ASU updates income tax disclosure requirements primarily by requiring specific categories and greater disaggregation within the rate reconciliation and disaggregation of income taxes paid by jurisdiction. This ASU is effective for annual periods beginning after December 15, 2024 and is applicable to the Company’s fiscal year beginning January 1, 2025, with early application permitted. The Company is currently evaluating the impact of adopting this ASU on its consolidated financial statements and disclosures.

Marketable Securities (Tables)

Marketable Securities (Tables)	6 Months Ended
	Jun. 30, 2024
Investments, Debt and Equity Securities [Abstract]
Summary of Available-for-sale Marketable Securities	The following table summarizes the Company’s available-for-sale marketable securities: June 30, 2024 Amortized Gross Unrealized Gross Unrealized Estimated Fair (In thousands) Marketable securities: U.S. Treasury and other government-backed securities $ 439,731 $ 69 $ ( 727 ) $ 439,073 Financial institution debt securities 228,035 58 ( 381 ) 227,712 Corporate debt securities 105,597 5 ( 125 ) 105,477 Other asset-backed securities 36,815 - ( 53 ) 36,762 Total $ 810,178 $ 132 $ ( 1,286 ) $ 809,024 December 31, 2023 Amortized Gross Unrealized Gross Unrealized Estimated Fair (In thousands) Marketable securities: U.S. Treasury and other government-backed securities $ 382,260 $ 302 $ ( 254 ) $ 382,308 Financial institution debt securities 246,270 92 ( 243 ) 246,119 Corporate debt securities 97,490 53 ( 135 ) 97,408 Other asset-backed securities 59,453 75 ( 24 ) 59,504 Total $ 785,473 $ 522 $ ( 656 ) $ 785,339

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2024
Fair Value Disclosures [Abstract]
Summary of Financial Assets Recognized at Fair Value on Recurring Basis	The Company’s financial assets recognized at fair value on a recurring basis consisted of the following: June 30, 2024 Total Level 1 Level 2 Level 3 (In thousands) Assets Cash equivalents and restricted cash equivalents $ 103,947 $ 103,947 $ - $ - Marketable securities: U.S. Treasury and other government-backed securities 439,073 203,649 235,424 - Financial institution debt securities 227,712 - 227,712 - Corporate debt securities 105,477 - 105,477 - Other asset-backed securities 36,762 - 36,762 - Total marketable securities 809,024 203,649 605,375 - Investment in Kyverna Therapeutics, Inc. 8,804 8,804 - - Total assets $ 921,775 $ 316,400 $ 605,375 $ - December 31, 2023 Total Level 1 Level 2 Level 3 (In thousands) Assets Cash equivalents and restricted cash equivalents $ 136,254 $ 136,254 $ - $ - Marketable securities: U.S. Treasury and other government-backed securities 382,308 120,556 261,752 - Financial institution debt securities 246,119 - 246,119 - Corporate debt securities 97,408 - 97,408 - Other asset-backed securities 59,504 - 59,504 - Total marketable securities 785,339 120,556 664,783 - Total assets $ 921,593 $ 256,810 $ 664,783 $ -

Accrued Expenses (Tables)

Accrued Expenses (Tables)	6 Months Ended
	Jun. 30, 2024
Payables and Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses consisted of the following: June 30, December 31, 2024 2023 (In thousands) Accrued research and development $ 21,961 $ 27,411 Employee compensation and benefits 14,901 26,615 Accrued legal and professional expenses 3,633 2,063 Accrued construction costs 2,327 6,891 Accrued other 2,305 4,037 Total accrued expenses $ 45,127 $ 67,017

Collaborations and Other Arra_2

Collaborations and Other Arrangements (Tables)	6 Months Ended
	Jun. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Changes in Accounts Receivable and Contract Liabilities	The following table presents changes in the Company’s accounts receivable and contract liabilities (in thousands): Balance at Additions Deductions Balance at End Six months ended June 30, 2024 Accounts receivable $ 36,456 $ 11,809 $ ( 35,936 ) $ 12,329 Contract liabilities - deferred revenue $ 60,993 $ - $ ( 10,757 ) $ 50,236 Balance at Additions Deductions Balance at End Six months ended June 30, 2023 Accounts receivable $ 3,768 $ 9,305 $ ( 8,017 ) $ 5,056 Contract liabilities - deferred revenue $ 63,771 $ - $ ( 28,919 ) $ 34,852
Summary of Revenues Recognized Resulting from Changes in Contract Liability Balance	During the six months ended June 30, 2024 and 2023, the Company recognized the following revenues as a result of changes in the contract liability balance (in thousands): Six Months Ended June 30, Revenue recognized in the period from: 2024 2023 Amounts included in the contract liability at the beginning of the period $ 10,757 $ 23,273

Investments and Other Assets (T

Investments and Other Assets (Tables)	6 Months Ended
	Jun. 30, 2024
Investments, All Other Investments [Abstract]
Schedule of Investments and Other Assets	Investments and other assets consisted of the following: June 30, December 31, 2024 2023 (In thousands) Investment in Kyverna $ 8,804 $ 10,000 Other investments 24,213 14,760 Restricted cash equivalents, long-term 13,605 13,605 Prepaid expenses and other assets, long-term 3,213 4,518 Total investments and other assets $ 49,835 $ 42,883

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2024
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Schedule of Stock-Based Compensation Expense	Stock-based compensation expense is classified in the condensed consolidated statements of operations and comprehensive loss as follows: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (In thousands) Research and development $ 25,439 $ 22,351 $ 45,600 $ 39,282 General and administrative 15,422 14,049 29,437 24,373 Total $ 40,861 $ 36,400 $ 75,037 $ 63,655
Summary of Restricted Stock Activity	The following table summarizes the Company’s RSU activity for the six months ended June 30, 2024: Number of Weighted Unvested restricted stock units as of December 31, 2023 4,041,753 $ 50.40 Granted 3,042,554 34.20 Vested ( 1,211,234 ) 51.67 Cancelled ( 501,576 ) 44.28 Unvested restricted stock units as of June 30, 2024 5,371,497 $ 41.51
Summary of Weighted Average Assumptions Used to Compute Fair Value of Option Granted	Weighted average assumptions used to apply this pricing model were as follows: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 Risk-free interest rate 4.3 % 4.1 % 4.2 % 4.4 % Expected term 5.6 years 5.6 years 6.0 years 6.0 years Expected volatility of underlying stock 76.3 % 78.8 % 76.4 % 78.7 % Expected dividend yield 0.0 % 0.0 % 0.0 % 0.0 %
Summary of Stock Option Activity	The following is a summary of stock option activity for the six months ended June 30, 2024: Number of Weighted Weighted Aggregate (In years) (In thousands) Outstanding at December 31, 2023 5,458,999 $ 50.38 6.65 $ 35,922 Granted 772,191 31.86 Exercised ( 190,246 ) 16.49 Forfeited ( 331,773 ) 77.99 Outstanding at June 30, 2024 5,709,171 $ 47.40 6.30 $ 15,820 Exercisable at June 30, 2024 4,290,920 $ 45.38 5.51 $ 15,812
2016 Employee Stock Purchase Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Summary of Weighted Average Assumptions Used to Compute Fair Value of Option Granted	The fair value of shares under the 2016 Plan was estimated at the beginning of the offering period using a Black-Scholes option-pricing model with the following assumptions: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 Risk-free interest rate 5.24 % 4.70 % 5.24 % 4.70 % Expected term 0.5 years 0.5 years 0.5 years 0.5 years Expected volatility of underlying stock 56.7 % 69.2 % 56.7 % 69.2 % Expected dividend yield 0.0 % 0.0 % 0.0 % 0.0 %

Loss Per Share (Tables)

Loss Per Share (Tables)	6 Months Ended
	Jun. 30, 2024
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Net Loss Per Share	Basic and diluted loss per share was calculated as follows: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (In thousands) Net loss $ ( 146,975 ) $ ( 123,681 ) $ ( 254,411 ) $ ( 226,807 ) Weighted average shares outstanding, basic and diluted 96,975 88,185 96,238 87,979 Net loss per share, basic and diluted $ ( 1.52 ) $ ( 1.40 ) $ ( 2.64 ) $ ( 2.58 )
Potential Dilutive Securities Excluded from Computation of Diluted Net Loss Per Common Share	The following common stock equivalents were excluded from the calculation of diluted loss per share because their inclusion would have been anti-dilutive: Three and Six Months Ended June 30, 2024 2023 (In thousands) Unvested restricted stock units 5,371 4,087 Stock options 5,709 5,901 11,080 9,988

Overview and Basis of Present_2

Overview and Basis of Presentation - Additional Information (Detail) $ in Millions	6 Months Ended
	Jun. 30, 2024 USD ($)
IPO [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Proceeds from common stock offering	$ 2,666.7

Marketable Securities - Summary

Marketable Securities - Summary of Available -for-sale Marketable Securities (Detail) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Marketable Securities [Line Items]
Amortized Cost	$ 810,178	$ 785,473
Gross Unrealized Gains	132	522
Gross Unrealized Losses	(1,286)	(656)
Estimated Fair Value	809,024	785,339
U.S. Treasury and Other Government - Backed Securities [Member]
Marketable Securities [Line Items]
Amortized Cost	439,731	382,260
Gross Unrealized Gains	69	302
Gross Unrealized Losses	(727)	(254)
Estimated Fair Value	439,073	382,308
Financial Institution Debt Securities [Member]
Marketable Securities [Line Items]
Amortized Cost	228,035	246,270
Gross Unrealized Gains	58	92
Gross Unrealized Losses	(381)	(243)
Estimated Fair Value	227,712	246,119
Corporate Debt Securities [Member]
Marketable Securities [Line Items]
Amortized Cost	105,597	97,490
Gross Unrealized Gains	5	53
Gross Unrealized Losses	(125)	(135)
Estimated Fair Value	105,477	97,408
Other Asset Backed Securities [Member]
Marketable Securities [Line Items]
Amortized Cost	36,815	59,453
Gross Unrealized Gains	0	75
Gross Unrealized Losses	(53)	(24)
Estimated Fair Value	$ 36,762	$ 59,504

Marketable Securities - Additio

Marketable Securities - Additional Information (Detail) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2024	Dec. 31, 2023
Marketable Securities [Line Items]
Realized gains or losses on marketable securities	$ 0	$ 0
Investments that matured beyond five years	$ 0	$ 0
Minimum
Marketable Securities [Line Items]
Available-for-sales Securities, non-current, maturity period	1 year
Maximum
Marketable Securities [Line Items]
Available-for-sales Securities, non-current, maturity period	5 years

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Financial Assets Recognized at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Marketable securities:
Investment in Kyverna Therapeutics, Inc.	$ 8,804	$ 10,000
Fair Value on Recurring Basis [Member]
Assets
Cash equivalents and restricted cash equivalents	103,947	136,254
Marketable securities:
Marketable securities	809,024	785,339
Investment in Kyverna Therapeutics, Inc.	8,804
Total Assets	921,775	921,593
Fair Value on Recurring Basis [Member] | U.S. Treasury and Other Government - Backed Securities [Member]
Marketable securities:
Marketable securities	439,073	382,308
Fair Value on Recurring Basis [Member] | Financial Institution Debt Securities [Member]
Marketable securities:
Marketable securities	227,712	246,119
Fair Value on Recurring Basis [Member] | Corporate Debt Securities [Member]
Marketable securities:
Marketable securities	105,477	97,408
Fair Value on Recurring Basis [Member] | Other Asset Backed Securities [Member]
Marketable securities:
Marketable securities	36,762	59,504
Fair Value on Recurring Basis [Member] | Level 1 [Member]
Assets
Cash equivalents and restricted cash equivalents	103,947	136,254
Marketable securities:
Marketable securities	203,649	120,556
Investment in Kyverna Therapeutics, Inc.	8,804
Total Assets	316,400	256,810
Fair Value on Recurring Basis [Member] | Level 1 [Member] | U.S. Treasury and Other Government - Backed Securities [Member]
Marketable securities:
Marketable securities	203,649	120,556
Fair Value on Recurring Basis [Member] | Level 2 [Member]
Marketable securities:
Marketable securities	605,375	664,783
Total Assets	605,375	664,783
Fair Value on Recurring Basis [Member] | Level 2 [Member] | U.S. Treasury and Other Government - Backed Securities [Member]
Marketable securities:
Marketable securities	235,424	261,752
Fair Value on Recurring Basis [Member] | Level 2 [Member] | Financial Institution Debt Securities [Member]
Marketable securities:
Marketable securities	227,712	246,119
Fair Value on Recurring Basis [Member] | Level 2 [Member] | Corporate Debt Securities [Member]
Marketable securities:
Marketable securities	105,477	97,408
Fair Value on Recurring Basis [Member] | Level 2 [Member] | Other Asset Backed Securities [Member]
Marketable securities:
Marketable securities	$ 36,762	$ 59,504

Accrued Expenses - Schedule of

Accrued Expenses - Schedule of Accrued Expenses (Detail) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Payables and Accruals [Abstract]
Accrued research and development	$ 21,961	$ 27,411
Employee compensation and benefits	14,901	26,615
Accrued legal and professional expenses	3,633	2,063
Accrued construction costs	2,327	6,891
Accrued other	2,305	4,037
Total accrued expenses	$ 45,127	$ 67,017

Collaborations and Other Arra_3

Collaborations and Other Arrangements - Summary of Changes in Accounts Receivable and Contract Liabilities (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Accounts receivable:
Accounts receivable, Balance at Beginning of Period	$ 36,456	$ 3,768
Accounts receivable, Additions	11,809	9,305
Accounts receivable, Deductions	(35,936)	(8,017)
Accounts receivable, Balance at End of Period	12,329	5,056
Contract liabilities:
Deferred revenue, Balance at Beginning of Period	60,993	63,771
Deferred revenue, Additions	0	0
Deferred revenue, Deductions	(10,757)	(28,919)
Deferred revenue, Balance at End of Period	$ 50,236	$ 34,852

Collaborations and Other Arra_4

Collaborations and Other Arrangements - Summary of Revenues Recognized Resulting from Changes in Contract Liability Balance (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Revenue from Contract with Customer [Abstract]
Amounts included in the contract liability at the beginning of the period	$ 10,757	$ 23,273

Collaborations and Other Arra_5

Collaborations and Other Arrangements - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended
	Oct. 31, 2023	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023	Dec. 31, 2022
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Costs to obtain or fulfill contract capitalized		$ 0		$ 0
Collaboration revenue		6,957,000	$ 13,594,000	35,892,000	$ 26,200,000
Deferred revenue		50,236,000	34,852,000	50,236,000	34,852,000	$ 60,993,000	$ 63,771,000
Regeneron Pharmaceuticals Inc. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Aggregate transaction price remaining to be recognized		36,800,000		36,800,000
Deferred revenue		36,800,000		36,800,000		47,100,000
Development and commercial milestone payments				320,000,000
Regeneron Pharmaceuticals Inc. [Member] | Related Party [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Accounts receivable		11,500,000		11,500,000		35,700,000
Regeneron Pharmaceuticals Inc. [Member] | Hemophilia Co Co Agreements
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue		4,400,000	2,800,000	7,600,000	5,800,000
Regeneron Pharmaceuticals Inc. [Member] | Regeneron Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue		6,400,000	7,300,000	13,800,000	14,100,000
Payments due		5,100,000	4,500,000	9,700,000	8,700,000
Deferred revenue	$ 30,000,000
Collaboration agreement extension period	two years
Collaboration term extension period	2026-04
Sparing Vision [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue		500,000	500,000	1,100,000	900,000
Deferred revenue		13,400,000		13,400,000		13,900,000
Sparing Vision [Member] | Related Party [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Accounts receivable		600,000		600,000		500,000
ReCode Therapeutics, Inc.
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Development and commercial milestone payments				262,000,000
AvenCell [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue			5,800,000	21,000,000	10,700,000
Accounts receivable		200,000		200,000		$ 200,000
Revenue			5,800,000		10,700,000
Kyverna Therapeutics Inc [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue		0		0
Revenue			0		400,000
ONK Therapeutics [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue		$ 0		$ 0
Revenue			$ 0		$ 100,000

Investments and Other Assets -

Investments and Other Assets - Schedule of Investments and Other Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023	Jun. 30, 2023
Investments, All Other Investments [Abstract]
Investment in Kyverna Therapeutics, Inc.	$ 8,804	$ 10,000
Other investments	24,213	14,760
Restricted cash equivalents, long-term	13,605	13,605	$ 11,957
Prepaid expenses and other assets, long-term	3,213	4,518
Total investments and other assets	$ 49,835	$ 42,883

Investments and Other Assets _2

Investments and Other Assets - Additional Information (Detail) - USD ($)	3 Months Ended			6 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Schedule of Equity Method Investments [Line Items]
Reclassification of other comprehensive loss - equity method investment		$ 2,132,000
Investments and other assets	$ 49,835,000			$ 49,835,000		$ 42,883,000
Change in fair value of investments, net	(20,354,000)		$ 0	(26,419,000)	$ 0
Collaboration revenue	6,957,000		13,594,000	35,892,000	26,200,000
Accrued expenses	45,127,000			45,127,000		67,017,000
AvenCell Therapeutics, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Reclassification of other comprehensive loss - equity method investment				2,100,000
Investments and other assets	9,600,000			9,600,000
Kyverna Therapeutics Inc [Member]
Schedule of Equity Method Investments [Line Items]
Investment Owned, Balance, Principal Amount	800,000			800,000
Change in fair value of investments, net	20,400,000			1,200,000
Investment Owned, Fair Value						10,000,000
Collaboration revenue	0			0
AvenCell [Member]
Schedule of Equity Method Investments [Line Items]
Change in fair value of investments, net				25,300,000
Investment Owned, Fair Value						11,800,000
Collaboration revenue			5,800,000	21,000,000	10,700,000
Accounts receivable	200,000			200,000		200,000
Accrued expenses	$ 1,000,000			$ 1,000,000		$ 1,000,000
AvenCell [Member] | AvenCell Therapeutics, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	33.33%			33.33%		33.33%
Collaboration revenue				$ 0
Sparing Vision [Member]
Schedule of Equity Method Investments [Line Items]
Investment Owned, Fair Value	$ 14,600,000			14,600,000
Collaboration revenue	$ 500,000		$ 500,000	$ 1,100,000	$ 900,000

Rewrite Acquisition - Additiona

Rewrite Acquisition - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Business Acquisition [Line Items]
Research and development	$ 114,207	$ 115,276	$ 226,054	$ 212,392
Common stock, shares issued	98,289,150		98,289,150		92,997,158

Leases - Additional Information

Leases - Additional Information (Detail) $ in Thousands	1 Months Ended	6 Months Ended
	Feb. 28, 2022 ft²	Jun. 30, 2024 USD ($) ft²	Jun. 30, 2023	Dec. 31, 2023 USD ($)
Lessee Lease Description [Line Items]
Operating lease right-of-use assets | $		$ 105,412		$ 115,375
Albany Lease [Member]
Lessee Lease Description [Line Items]
Operating lease, existence of option to extend			true
840 Winter Street Lease [Member]
Lessee Lease Description [Line Items]
Area of space leased	140,000
Operating lease, description	Separately, the Company entered into an agreement in February 2022, later amended in June 2023, to lease approximately 140,000 square feet of office, general laboratory and planned good manufacturing practice (“GMP”) manufacturing space at 840 Winter Street in Waltham
Cambridge [Member]
Lessee Lease Description [Line Items]
Area of space leased		230,000

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Equity-based compensation expense	$ 40,861	$ 36,400	$ 75,037	$ 63,655
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Equity-based compensation expense	25,439	22,351	45,600	39,282
General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Equity-based compensation expense	$ 15,422	$ 14,049	$ 29,437	$ 24,373

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) $ / shares in Units, $ in Millions	1 Months Ended				3 Months Ended		6 Months Ended
	Mar. 31, 2024 $ / shares shares	Mar. 31, 2023 $ / shares shares	Mar. 31, 2022 Tranche $ / shares shares	May 31, 2016	Jun. 30, 2024 USD ($) $ / shares shares	Jun. 30, 2023 USD ($) $ / shares shares	Jun. 30, 2024 USD ($) $ / shares shares	Jun. 30, 2023 USD ($) $ / shares shares	Dec. 31, 2023 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares issued					98,289,150		98,289,150		92,997,158
Weighted Average Grant Date Fair Value per Share, Granted | $ / shares							$ 34.2
Number of Shares, Granted							3,042,554
Unvested restricted stock units					5,371,497		5,371,497		4,041,753
Risk-free interest rate					4.30%	4.10%	4.20%	4.40%
Expected dividend yield					0%	0%	0%	0%
Expected volatility					76.30%	78.80%	76.40%	78.70%
Expected term					5 years 7 months 6 days	5 years 7 months 6 days	6 years	6 years
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining vesting period							1 year 2 months 19 days
Weighted average grant date fair value per share | $ / shares					$ 17.5	$ 29.8	$ 22.01	$ 28.92
Total intrinsic value of stock options exercised | $					$ 0.8	$ 0.8	$ 2	$ 1.9
Unrecognized compensation cost related to stock options | $					$ 43.5		$ 43.5
2015 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Description of stock options granted under the Plan							Stock options generally vest as to one-third on the first anniversary of the original vesting date, with the balance vesting monthly over the remaining two years, unless they contain specific vesting provisions. The maximum term of stock options granted under the 2015 Plan is ten years.
Shares available for future issuance					4,614,029		4,614,029
Percentage of cumulative increase in number of shares for future issuance							4%
2024 Inducement Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future issuance					850,000		850,000
2016 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Description of stock options granted under the Plan				The 2016 Plan allows eligible employees to purchase shares of the Company’s common stock on the last day of each predetermined six-month offering period at 85% of the lower of the fair market value per share at the beginning or end of the applicable offering period.
Percentage of fair market value of common stock				85%
Shares available for future issuance					989,736		989,736
Common stock, shares issued					87,751	69,631	87,751	69,631
Weighted Average Grant Date Fair Value per Share, Granted | $ / shares							$ 19.02	$ 29.45
Risk-free interest rate					5.24%	4.70%	5.24%	4.70%
Expected dividend yield					0%	0%	0%	0%
Expected volatility					56.70%	69.20%	56.70%	69.20%
Expected term					6 months	6 months	6 months	6 months
Service Awards [Member] | RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining vesting period	3 years	3 years
Weighted Average Grant Date Fair Value per Share, Granted | $ / shares	$ 32.66	$ 40.75
Number of Shares, Granted	2,157,921	2,195,135
Unvested restricted stock units					4,478,007		4,478,007
Market Awards [Member] | RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested restricted stock units					438,329		438,329
Market Awards [Member] | RSUs [Member] | Senior Executives [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining vesting period	3 years	3 years	3 years
Weighted Average Grant Date Fair Value per Share, Granted | $ / shares	$ 51.12	$ 68.55	$ 126.49
Number of Shares, Granted	235,858	181,743	55,144
Risk-free interest rate	4.28%	4.60%	1.44%
Expected dividend yield	0%	0%	0%
Expected volatility	77.20%	84.34%	82.53%
Expected term	3 years	3 years	3 years
Performance Based Awards with TSR Multiplier [Member] | RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested restricted stock units					410,743		410,743
Performance Based Awards with TSR Multiplier [Member] | RSUs [Member] | Senior Executives [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted Average Grant Date Fair Value per Share, Granted | $ / shares	$ 36.16
Number of Shares, Granted	444,117
Risk-free interest rate	4.28%
Expected dividend yield	0%
Expected volatility	77.20%
Expected term	3 years
Performance Based Awards [Member] | RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted Average Grant Date Fair Value per Share, Granted | $ / shares					$ 25.16	$ 38.7	$ 34.2	$ 42.45
Total fair value amount, Vested | $					$ 4.6	$ 6.2	$ 35.5	$ 18.3
Unvested restricted stock units					44,418		44,418
Unrecognized equity-based compensation expense related to restricted stock | $					$ 156.1		$ 156.1
Weighted average period of unrecognized compensation costs							1 year 9 months 18 days
Performance Based Awards [Member] | RSUs [Member] | Non-executive Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Granted			66,296
Number of tranches | Tranche			2
Performance Based Awards [Member] | First Anniversary of Original Vesting Date [Member] | RSUs [Member] | Non-executive Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Granted			21,878
Maximum | 2016 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares issued					500,000		500,000
Maximum | Performance Based Awards with TSR Multiplier [Member] | RSUs [Member] | Senior Executives [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share Based Compensation Arrangements by Share Based Payment Award, Performance Shares	200%
TSR modifier	125%
Minimum | Performance Based Awards with TSR Multiplier [Member] | RSUs [Member] | Senior Executives [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share Based Compensation Arrangements by Share Based Payment Award, Performance Shares	0%
TSR modifier	75%

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Restricted Stock Activity (Detail)	6 Months Ended
	Jun. 30, 2024 $ / shares shares
Share-Based Payment Arrangement [Abstract]
Number of Shares, Unvested, Beginning balance | shares	4,041,753
Number of Shares, Granted | shares	3,042,554
Number of Shares, Vested | shares	(1,211,234)
Number of Shares, Cancelled | shares	(501,576)
Number of Shares, Unvested, Ending balance | shares	5,371,497
Weighted Average Grant Date Fair Value per Share, Unvested, Beginning balance | $ / shares	$ 50.4
Weighted Average Grant Date Fair Value per Share, Granted | $ / shares	34.2
Weighted Average Grant Date Fair Value per Share, Vested | $ / shares	51.67
Weighted Average Grant Date Fair Value per Share, Cancelled | $ / shares	44.28
Weighted Average Grant Date Fair Value per Share, Unvested, Ending balance | $ / shares	$ 41.51

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Weighted Average Assumptions Used to Compute Fair Value of Option Granted (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Risk-free interest rate	4.30%	4.10%	4.20%	4.40%
Expected term	5 years 7 months 6 days	5 years 7 months 6 days	6 years	6 years
Expected volatility of underlying stock	76.30%	78.80%	76.40%	78.70%
Expected dividend yield	0%	0%	0%	0%
2016 Employee Stock Purchase Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Risk-free interest rate	5.24%	4.70%	5.24%	4.70%
Expected term	6 months	6 months	6 months	6 months
Expected volatility of underlying stock	56.70%	69.20%	56.70%	69.20%
Expected dividend yield	0%	0%	0%	0%

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Stock Option Activity (Detail) $ / shares in Units, $ in Thousands		6 Months Ended
	Dec. 31, 2023 USD ($) $ / shares shares	Jun. 30, 2024 USD ($) $ / shares shares
Share-Based Payment Arrangement [Abstract]
Number of Options, Outstanding, Beginning Balance | shares		5,458,999
Number of options, Granted | shares		772,191
Number of options, Exercised | shares		(190,246)
Number of options, Forfeited | shares		(331,773)
Number of Options, Outstanding, Ending Balance | shares	5,458,999	5,709,171
Number of Options, Exercisable | shares		4,290,920
Weighted Average Exercise Price per Share, Outstanding, Beginning Balance | $ / shares		$ 50.38
Weighted Average Exercise Price per Share, Granted | $ / shares		31.86
Weighted Average Exercise Price per Share, Exercised | $ / shares		16.49
Weighted Average Exercise Price per Share, Forfeited | $ / shares		77.99
Weighted Average Exercise Price per Share, Outstanding, Ending Balance | $ / shares	$ 50.38	47.4
Weighted Average Exercise Price per Share, Exercisable | $ / shares		$ 45.38
Weighted Average Remaining Contractual Term, Outstanding	6 years 7 months 24 days	6 years 3 months 18 days
Weighted Average Remaining Contractual Term, Exercisable		5 years 6 months 3 days
Aggregate Intrinsic Value, Outstanding | $	$ 35,922	$ 15,820
Aggregate Intrinsic Value, Exercisable | $		$ 15,812

Loss Per Share - Schedule of Ba

Loss Per Share - Schedule of Basic and Diluted Net Loss Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2024	Jun. 30, 2023
Earnings Per Share [Abstract]
Net Income (Loss)	$ (146,975)	$ (107,436)	$ (123,681)	$ (103,126)	$ (254,411)	$ (226,807)
Weighted average shares outstanding, basic	96,975		88,185		96,238	87,979
Weighted average shares outstanding, diluted	96,975		88,185		96,238	87,979
Net loss per share, basic	$ (1.52)		$ (1.4)		$ (2.64)	$ (2.58)
Net loss per share, diluted	$ (1.52)		$ (1.4)		$ (2.64)	$ (2.58)

Loss Per Share - Potential Dilu

Loss Per Share - Potential Dilutive Securities Excluded from Computation of Diluted Net Loss Per Common Share (Detail) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive securities excluded from computation of diluted net loss per common share	11,080	9,988	11,080	9,988
Unvested Restricted Stock Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive securities excluded from computation of diluted net loss per common share	5,371	4,087	5,371	4,087
Employee Stock Option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive securities excluded from computation of diluted net loss per common share	5,709	5,901	5,709	5,901

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended			6 Months Ended
	Jun. 30, 2024	Feb. 29, 2024	Mar. 31, 2022	Jun. 30, 2024
2022 Sales Agreement [Member] | Maximum
Class Of Stock [Line Items]
Proceeds from common stock offering			$ 400
Amended 2022 Sales Agreement [Member]
Class Of Stock [Line Items]
Proceeds from common stock offering				$ 94.4
Percentage of gross proceeds from common stock as sales agent cash commission		3%
Stock Issued During Period, Shares, New Issues	11,320,924			3,802,761
Common stock price per share	$ 25.58			$ 25.58
Legal accounting and other fees				$ 0.2
Proceeds from common stock offering	$ 331.7			$ 331.7
Amended 2022 Sales Agreement [Member] | Maximum
Class Of Stock [Line Items]
Proceeds from common stock offering		$ 750
Amended 2022 Sales Agreement [Member] | Minimum
Class Of Stock [Line Items]
Proceeds from common stock offering		$ 400