Beam Therapeutics (BEAM) 10-Q 9 May 22 2022 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2022	May 02, 2022
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q1
Trading Symbol	BEAM
Entity Registrant Name	Beam Therapeutics Inc.
Entity Central Index Key	0001745999
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
Title of 12(b) Security	Common Stock, par value $0.01 per share
Security Exchange Name	NASDAQ
Entity File Number	001-39208
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	81-5238376
Entity Address, Address Line One	238 Main Street
Entity Address, City or Town	Cambridge
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02142
City Area Code	857
Local Phone Number	327-8775
Document Quarterly Report	true
Document Transition Report	false
Entity Common Stock, Shares Outstanding		70,266,761

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 296,821	$ 559,994
Marketable securities	925,779	405,653
Collaboration receivable		300,000
Prepaid expenses and other current assets	16,884	7,360
Total current assets	1,239,484	1,273,007
Property and equipment, net	94,288	84,258
Restricted cash	12,746	12,746
Operating lease right-of-use assets	105,543	102,718
Other assets	1,341	1,724
Total assets	1,453,402	1,474,453
Current liabilities:
Accounts payable	6,266	7,474
Accrued expenses and other current liabilities	24,062	28,921
Accrued sub-license fees	33,125	38,743
Derivative liabilities	28,600	42,200
Current portion of deferred revenue	115,049	86,270
Current portion of lease liability	9,359	7,540
Current portion of equipment financing liability	2,337	2,287
Total current liabilities	218,798	213,435
Long-term lease liability	136,034	134,810
Long-term equipment financing liability	2,404	3,007
Contingent consideration liabilities	30,915	31,367
Long-term portion of deferred revenue	225,093	262,303
Other liabilities	11,090	2,793
Total liabilities	624,334	647,715
Commitments and contingencies (See Note 7, Leases, Note 9, License agreements and Note 10, Collaboration and license agreements)
Stockholders’ equity:
Preferred stock, $0.01 par value; 25,000,000 shares authorized, and no shares issued or outstanding at March 31, 2022 and December 31, 2021, respectively
Common stock, $0.01 par value; 250,000,000 shares authorized, 69,785,836 and 68,581,251 issued, and 69,753,023 and 68,389,425 outstanding at March 31, 2022 and December 31, 2021, respectively	698	684
Additional paid-in capital	1,668,567	1,594,378
Accumulated other comprehensive (loss) income	(2,709)	(50)
Accumulated deficit	(837,488)	(768,274)
Total stockholders’ equity	829,068	826,738
Total liabilities and stockholders equity	$ 1,453,402	$ 1,474,453

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) (Unaudited) - $ / shares	Mar. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Preferred stock, par or stated value per share	$ 0.01	$ 0.01
Preferred stock, shares authorized	25,000,000	25,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par or stated value per share	$ 0.01	$ 0.01
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	69,785,836	68,581,251
Common stock, shares outstanding	69,753,023	68,389,425

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Other Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Income Statement [Abstract]
License and collaboration revenue	$ 8,432	$ 6
Revenue, Product and Service [Extensible List]	us-gaap:LicenseMember	us-gaap:LicenseMember
Operating expenses:
Research and development	$ 65,410	$ 190,106
General and administrative	19,247	10,273
Total operating expenses	84,657	200,379
Loss from operations	(76,225)	(200,373)
Other income (expense):
Change in fair value of derivative liabilities	13,600	(1,900)
Change in fair value of non-controlling equity investments	(7,685)	1,039
Change in fair value of contingent consideration liabilities	452	(305)
Interest and other income (expense), net	644	(21)
Total other income (expense)	7,011	(1,187)
Net loss	(69,214)	(201,560)
Unrealized gain (loss) on marketable securities	(2,659)	(15)
Comprehensive loss	$ (71,873)	$ (201,575)
Net loss per common share, basic	$ (1.01)	$ (3.35)
Net loss per common share, diluted	$ (1.01)	$ (3.35)
Weighted-average common shares outstanding, basic	68,703,864	60,210,120
Weighted-average common shares outstanding, diluted	68,703,864	60,210,120

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning Balance at Dec. 31, 2020	$ 245,561	$ 573	$ 642,633	$ (9)	$ (397,636)
Beginning Balance, Shares at Dec. 31, 2020		57,254,178
Issuance of common stock from private placement/At-the-Market offering, net of issuance costs	252,005	$ 28	251,977
Issuance of common stock from private placement/At-the-Market offering, net of issuance costs, Shares		2,795,700
Issuance of common stock to acquire Guide	120,032	$ 10	120,022
Issuance of common stock to acquire Guide, Shares		1,087,153
Vesting of restricted common stock		$ 4	(4)
Vesting of restricted common stock, Shares		398,804
Stock-based compensation	4,648		4,648
Exercise of common stock options	1,758	$ 2	1,756
Exercise of common stock options, Shares		199,284
Other comprehensive income (loss)	(15)			(15)
Net loss	(201,560)				(201,560)
Ending Balance at Mar. 31, 2021	422,429	$ 617	1,021,032	(24)	(599,196)
Ending Balance, Shares at Mar. 31, 2021		61,735,119
Beginning Balance at Dec. 31, 2021	826,738	$ 684	1,594,378	(50)	(768,274)
Beginning Balance, Shares at Dec. 31, 2021		68,389,425
Purchase of common stock under ESPP	1,412		1,412
Purchase of common stock under ESPP, Shares		28,990
Issuance of common stock from private placement/At-the-Market offering, net of issuance costs	53,936	$ 9	53,927
Issuance of common stock from private placement/At-the-Market offering, net of issuance costs, Shares		874,770
Vesting of restricted common stock		$ 3	(3)
Vesting of restricted common stock, Shares		283,186
Stock-based compensation	18,035		18,035
Exercise of common stock options	$ 820	$ 2	818
Exercise of common stock options, Shares	176,652	176,652
Other comprehensive income (loss)	$ (2,659)			(2,659)
Net loss	(69,214)				(69,214)
Ending Balance at Mar. 31, 2022	$ 829,068	$ 698	$ 1,668,567	$ (2,709)	$ (837,488)
Ending Balance, Shares at Mar. 31, 2022		69,753,023

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Private Placement
Stock issuance costs		$ 8
ATM Offering
Stock issuance costs	$ 1.3

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating activities
Net loss	$ (69,214)	$ (201,560)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	3,312	1,398
Amortization of investment discount (premiums)	(390)	15
In-process research and development charge		154,953
Stock-based compensation expense	18,035	4,648
Change in operating lease right-of-use assets	1,997	2,359
Change in fair value of derivative liabilities	(13,600)	1,900
Change in fair value of contingent consideration liabilities	(452)	305
Change in fair value of non-controlling equity investments	7,685	(1,039)
Other	3	63
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(9,185)	(2,365)
Other long-term assets		(185)
Accounts payable	(1,252)	(666)
Accrued expenses and other liabilities	(16,533)	(4,458)
Operating lease liabilities	(1,780)	6,111
Collaboration receivable	300,000
Deferred revenue	(8,432)	(6)
Other long-term liabilities	8,296	(51)
Net cash provided by (used in) operating activities	218,490	(38,578)
Investing activities
Purchases of property and equipment	(7,259)	(11,478)
Purchases of marketable securities	(690,390)	(289,218)
Maturities of marketable securities	160,310	20,450
Net cash acquired from Guide		620
Net cash used in investing activities	(537,339)	(279,626)
Financing activities
Proceeds from issuance of common shares, net of commissions	54,003	260,000
Proceeds from issuances of stock under ESPP	1,412
Payment of equity offering costs	(6)	(7,955)
Repayment of equipment financings	(553)	(529)
Proceeds from exercise of stock options	820	1,758
Net cash provided by financing activities	55,676	253,274
Net change in cash, cash equivalents and restricted cash	(263,173)	(64,930)
Cash, cash equivalents and restricted cash—beginning of period	572,740	177,011
Cash, cash equivalents and restricted cash—end of period	309,567	112,081
Supplemental disclosure of cash flow information:
Cash paid for interest	113	159
Supplemental disclosure of noncash investing and financing activities:
Property and equipment additions in accounts payable and accrued expenses	15,306	6,671
Operating lease liabilities arising from obtaining right-of-use assets	4,822	23,366
Equity issuance costs in accounts payable and accrued expenses	$ 67	250
Contingent consideration liabilities assumed in asset acquisition		36,513
Fair value of equity instruments issued in connection with asset acquisition		$ 120,032

Nature of the Business and Basi

Nature of the Business and Basis of Presentation	3 Months Ended
	Mar. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of the Business and Basis of Presentation	1. Nature of the business and basis of presentation Organization Beam Therapeutics Inc., which we refer to herein as the “Company” or “Beam,” is a biotechnology company committed to establishing the leading, fully integrated platform for precision genetic medicines. Beam’s vision is to provide life-long cures to patients suffering from genetic diseases. The Company was incorporated on January 25, 2017 as a Delaware corporation and began operations in July 2017. Its principal offices are in Cambridge, Massachusetts. Liquidity and capital resources Since its inception, the Company has devoted substantially all of its resources to building its base editing platform and advancing development of its portfolio of programs, establishing and protecting its intellectual property, conducting research and development activities, making arrangements to conduct manufacturing activities with contract manufacturing organizations, research and development costs including preclinical studies and IND-enabling studies, organizing and staffing the Company, maintaining its facilities and new facility build-outs, business planning, raising capital and providing general and administrative support for these operations. The Company is also in the process of developing internal manufacturing capabilities. The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry including, but not limited to, technical risks associated with the successful research, development and manufacturing of product candidates, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, compliance with government regulations and the ability to secure additional capital to fund operations. Current and future programs will require significant research and development efforts, including extensive preclinical and clinical testing and regulatory approval prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales. In April 2021, the Company entered into an at the market, or ATM, sales agreement, or the Sales Agreement, with Jefferies LLC, or Jefferies, pursuant to which the Company was entitled to offer and sell, from time to time at prevailing market prices, shares of the Company’s common stock having aggregate gross proceeds of up to $ 300.0 million. The Company agreed to pay Jefferies a commission of up to 3.0 % of the aggregate gross sale proceeds of any shares sold by Jefferies under the Sales Agreement. Between April and July 2021, the Company sold 2,908,009 shares of its common stock under the Sales Agreement at an average price of $ 103.16 per share for aggregate gross proceeds of $ 300.0 million, before deducting commissions and offering expenses payable by the Company. In July 2021, the Company and Jefferies entered into an amendment to the Sales Agreement to provide for an increase in the aggregate offering amount under the Sales Agr eement, such that as of July 7, 2021, the Company may offer and sell shares of common stock having an aggregate offering price of an additional $ 500.0 million. As of March 31, 2022, the Company has sold 2,873,956 additional shares of its common stock under the amended Sales Agreement at an average price of $ 92.71 per share for aggregate gross proceeds of $ 266.5 million, before deducting commissions and offering expenses payable by the Company. Since its inception, the Company has incurred substantial losses and had an accumulated deficit of $ 837.5 million as of March 31, 2022. The Company expects to generate operating losses and negative operating cash flows for the foreseeable future. The Company expects that its cash, cash equivalents, and marketable securities as of March 31, 2022 of $ 1.2 billion will be sufficient to fund its operations for at least the next 12 months from the date of issuance of these financial statements. The Company will need additional financing to support its continuing operations and pursue its growth strategy. Until such time as the Company can generate significant revenue from product sales, if ever, it expects to finance its operations through a combination of equity offerings, debt financings, collaborations, strategic alliances and licensing arrangements. The Company may be unable to raise additional funds or enter into such other agreements when needed on favorable terms or at all. The inability to raise capital as and when needed would have a negative impact on the Company’s financial condition and its ability to pursue its business strategy. The Company will need to generate significant revenue to achieve profitability, and it may never do so. COVID-19-related significant risks and uncertainties With the ongoing concerns related to the COVID-19 pandemic, the Company has maintained its business continuity plans to address and mitigate the impact of the COVID-19 pandemic on its business. In March 2020, to protect the health of its employees, and their families and communities, the Company restricted access to its offices to personnel who performed critical activities that must be completed on-site, limited the number of such personnel that could be present at its facilities at any one time, and requested that most of its employees work remotely. In May 2021, as certain states eased restrictions, the Company established new protocols to better allow its full laboratory staff access to the Company’s facilities. These protocols included several shifts working over a seven-day-week protocol. In June 2021, as certain states continued to ease restrictions, the Company started to allow its entire workforce the ability to work on-site at the Company’s facilities, with fewer restrictions, particularly for vaccinated employees. The Company expects to continue incurring additional costs to ensure it adheres to the guidelines instituted by the Centers for Disease Control and Prevention and to provide a safe working environment to its onsite employees. The extent to which the COVID-19 pandemic impacts the Company’s business, its corporate development objectives, results of operations and financial condition, and the value of and market for its common stock, will depend on future developments that are highly uncertain and cannot be predicted with confidence at this time, such as the ultimate duration of the pandemic, travel restrictions, quarantines, social distancing and business closure requirements, and the effectiveness of actions taken globally to contain and treat the disease. Disruptions to the global economy and supply chain, disruption of global healthcare systems, and other significant impacts of the COVID-19 pandemic could have a material adverse effect on the Company’s business, financial condition, results of operations and growth prospects. While the COVID-19 pandemic did not significantly impact the Company’s business or results of operations during the three months ended March 31, 2022 , the length and extent of the pandemic, its consequences, and containment efforts will determine the future impact on the Company’s operations and financial condition.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. S ummary of significant accounting policies The Company’s significant accounting policies are disclosed in the audited consolidated financial statements for the year ended December 31, 2021, and notes thereto, which are included in the Company’s Annual Report on Form 10-K that was filed with the Securities and Exchange Commission on February 28, 2022, or the 2021 Form 10-K. Since the date of those financial statements, there have been no material changes to Beam’s significant accounting policies. Basis of presentation The accompanying condensed consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles, or GAAP. Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification, or ASC, and Accounting Standards Update, or ASU, of the Financial Accounting Standards Board, or FASB. Principles of consolidation The accompanying condensed consolidated financial statements include the results of operations of the Company and its wholly-owned subsidiaries. All intercompany transactions and balances have been eliminated in consolidation. Use of estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, and the disclosure of contingent assets and liabilities as of and during the reporting period. The Company bases its estimates and assumptions on historical experience when available and on various factors that it believes to be reasonable under the circumstances. Significant estimates and assumptions reflected in these condensed consolidated financial statements include, but are not limited to, incremental borrowing rate used in the calculation of lease liabilities, research and development expenses, stock-based compensation, contingent consideration liabilities, success payments and certain judgements regarding revenue recognition. Actual results could differ from these estimates. Cash, cash equivalents, and restricted cash Cash and cash equivalents consist of standard checking accounts, money market accounts, and all highly liquid investments with a remaining maturity of three months or less at the date of purchase. Restricted cash represents collateral provided for letters of credit issued as security deposits in connection with the Company’s leases of its corporate and manufacturing facilities. The following table reconciles cash, cash equivalents, and restricted cash reported within the Company’s condensed consolidated balance sheets to the total of the amounts shown in the condensed consolidated statements of cash flows (in thousands): March 31, March 31, Cash and cash equivalents $ 296,821 $ 97,241 Restricted cash 12,746 14,840 Total cash, cash equivalents, and restricted cash $ 309,567 $ 112,081

Property and Equipment, Net

Property and Equipment, Net	3 Months Ended
	Mar. 31, 2022
Property, Plant and Equipment [Abstract]
Property and Equipment, Net	3. P roperty and equipment, net Property and equipment consist of the following (in thousands): March 31, December 31, Leasehold improvements $ 58,041 $ 57,760 Lab equipment 35,489 29,905 Furniture and fixtures 3,699 3,679 Computer equipment 1,866 1,646 Construction in process 14,527 7,349 Total property and equipment 113,622 100,339 Less accumulated depreciation ( 19,334 ) ( 16,081 ) Property and equipment, net $ 94,288 $ 84,258 The following table summarizes depreciation expense incurred (in thousands): Three Months Ended March 31, 2022 2021 Depreciation expense $ 3,262 $ 1,398

Fair Value of Financial Instrum

Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2022
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	4. f air value of financial instruments The Company’s financial instruments that are measured at fair value on a recurring basis consist of cash equivalents, marketable securities, equity securities of Verve Therapeutics, Inc, or Verve, contingent consideration liabilities related to the agreement and plan of merger pursuant to which the Company acquired Guide, or the Guide Merger Agreement, and success payment derivative liabilities pursuant to the license agreement, or the Harvard License Agreement, between President and Fellows of Harvard University, or Harvard, and the Company, and the license agreement, or the Broad License Agreement, between The Broad Institute, Inc., or Broad Institute, and the Company. The following tables set forth the fair value of the Company’s financial assets and liabilities by level within the fair value hierarchy at March 31, 2022 (in thousands): Carrying Fair Level 1 Level 2 Level 3 Assets Cash equivalents: Money market funds $ 152,020 $ 152,020 $ 152,020 $ — $ — Commercial paper 144,801 144,801 — 144,801 — Marketable securities: Commercial paper 730,967 730,967 — 730,967 — Corporate notes 18,125 18,125 — 18,125 — U.S. Treasury securities 164,205 164,205 — 164,205 — Equity securities included in marketable securities: Corporate equity securities 12,482 12,482 12,482 — — Total assets $ 1,222,600 $ 1,222,600 $ 164,502 $ 1,058,098 $ — Liabilities Success payment liability – Harvard $ 14,200 $ 14,200 $ — $ — $ 14,200 Success payment liability – Broad Institute 14,400 14,400 — — 14,400 Contingent consideration liability – Technology 24,531 24,531 $ — $ — $ 24,531 Contingent consideration liability – Product 6,384 6,384 — — 6,384 Total liabilities $ 59,515 $ 59,515 $ — $ — $ 59,515 The following tables set forth the fair value of the Company’s financial assets and liabilities by level within the fair value hierarchy at December 31, 2021 (in thousands): Carrying Fair Level 1 Level 2 Level 3 Assets Cash equivalents: Money market funds $ 540,094 $ 540,094 $ 540,094 $ — $ — Commercial paper 13,997 13,997 — 13,997 — Corporate notes 5,903 5,903 — 5,903 — Marketable securities: Commercial paper 368,743 368,743 — 368,743 — Corporate notes 16,743 16,743 — 16,743 — Equity securities included in marketable securities Corporate equity securities 20,167 20,167 20,167 — — Total assets $ 965,647 $ 965,647 $ 560,261 $ 405,386 $ — Liabilities Success payment liability – Harvard $ 21,000 $ 21,000 $ — $ — $ 21,000 Success payment liability – Broad Institute 21,200 21,200 — — 21,200 Contingent consideration liability – Technology 24,359 $ 24,359 — — 24,359 Contingent consideration liability – Product 7,008 7,008 — — 7,008 Total liabilities $ 73,567 $ 73,567 $ — $ — $ 73,567 Cash equivalents – Money market funds included within cash equivalents are classified within Level 1 of the fair value hierarchy because they are valued using quoted market prices in active markets. Commercial paper and corporate notes are classified within Level 2 of the fair value hierarchy because pricing inputs are other than quoted prices in active markets, which are either directly or indirectly observable as of the reporting date, and fair value is determined through the use of models or other valuation methodologies. Marketable securities – Marketable securities, excluding corporate equity securities, are classified within Level 2 of the fair value hierarchy because pricing inputs are other than quoted prices in active markets, which are either directly or indirectly observable as of the reporting date, and fair value is determined using models or other valuation methodologies. The Company holds an investment in Verve consisting of shares of Verve’s common stock. Prior to Verve's initial public offering in June 2021, the Company valued such investment based on the cost of the equity securities adjusted for any observable market transactions. Following Verve's initial public offering, the equity securities have a readily determinable fair value; however, they were subject to transfer restrictions for 6 months following Verve's initial public offering. As of March 31, 2022 , the Company owned 546,970 shares of Verve's common stock valued at $ 12.5 million, which is included in marketable securities in the condensed consolidated balance sheet. In addition the Company recorded other expense of $ 7.7 million and other income of $ 1.0 million for the three months ended March 31, 2022, and 2021 respectively, related to the changes in fair value of Verve's stock. Pursuant to ASU No. 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities , the Company records changes in the fair value of its investments in equity securities to other income (expense), in the Company’s condensed consolidated statements of operations. Success payment liabilities – As discussed further in Note 9, License agreements , the Company is required to make payments to Harvard and Broad Institute based upon the achievement of specified multiples of the initial weighted average value of the Company’s Series A Preferred Stock or, subsequent to the Company’s initial public offering, or IPO, the market value of the Company's common stock, at specified valuation dates. The Company’s liability for the share-based success payments under the Harvard and Broad License Agreements is carried at fair value. To determine the estimated fair value of the success payment liability, the Company uses a Monte Carlo simulation methodology, which models the future movement of stock prices based on several key variables. The following variables were incorporated in the calculation of the estimated fair value of the Harvard and Broad Institute success payment liabilities: Harvard Broad Institute March 31, December 31, March 31, December 31, Fair value of common stock (per share) $ 57.30 $ 79.69 $ 57.30 $ 79.69 Expected volatility 80 % 76 % 80 % 76 % Expected term (years) 0.10 - 7.25 0.10 - 7.49 0.10 - 8.11 0.10 - 8.36 The computation of expected volatility was estimated using available information about the historical volatility of stocks of similar publicly traded companies in addition to the Company's own data for a period matching the expected term assumption. In addition, the Company incorporated the estimated number, timing, and probability of valuation measurement dates in the calculation of the success payment liability. The following table reconciles the change in the fair value of success payment liabilities based on Level 3 inputs (in thousands): Three Months Ended March 31, 2022 Harvard Broad Institute Total Balance at December 31, 2021 $ 21,000 $ 21,200 $ 42,200 Change in fair value ( 6,800 ) ( 6,800 ) ( 13,600 ) Balance at March 31, 2022 $ 14,200 $ 14,400 $ 28,600 Contingent consideration liabilities – As discussed further in Note 8, Guide acquisition , under the Guide Merger Agreement, Guide’s former stockholders and optionholders are eligible to receive up to an additional $ 100.0 million in technology milestone payments and $ 220.0 million in product milestone payments, payable in the Company’s common stock valued using the volume-weighted average price of the Company’s stock over the ten-day trading period ending two trading days prior to the date on which the applicable milestone is achieved. As these milestones are payable in the Company’s common stock, the milestone payments result in liability classification under ASC 480, Distinguishing Liabilities from Equity . These contingent consideration liabilities are carried at fair value which was estimated by applying a probability-based model, which utilized inputs based on timing of achievement that were unobservable in the market. These contingent consideration liabilities are classified within Level 3 of the fair value hierarchy. The following table reconciles the change in fair value of the contingent consideration liabilities based on level 3 inputs (in thousands): Three Months Ended March 31, 2022 Technology Milestones Product Milestones Total Balance at December 31, 2021 $ 24,359 $ 7,008 $ 31,367 Change in fair value 172 ( 624 ) ( 452 ) Balance at March 31, 2022 $ 24,531 $ 6,384 $ 30,915 The following variables were incorporated in the calculation of the estimated fair value of the contingent consideration liabilities: Technology Milestones Product Milestones March 31, December 31, March 31, December 31, Discount Rate 8.50 % 7.50 % 8.50 % 7.50 % Probability of Achievement 10 - 75 % 10 - 75 % 2 - 15 % 2 - 15 % Projected Year of Achievement 2022 - 2023 2022 - 2023 2024 - 2029 2023 - 2029

Marketable Securities

Marketable Securities	3 Months Ended
	Mar. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	5. Marketable securities The following table summarizes the Company’s marketable securities held at March 31, 2022 (in thousands): Amortized Cost Gross Gross Fair Value Commercial paper $ 733,068 $ — $ ( 2,101 ) $ 730,967 Corporate notes 18,249 — ( 124 ) 18,125 U.S. Treasury securities 164,689 2 ( 486 ) 164,205 Corporate equity securities 12,482 — — 12,482 Total $ 928,488 $ 2 $ ( 2,711 ) $ 925,779 The following table summarizes the Company’s marketable securities held at December 31, 2021 (in thousands): Amortized Cost Gross Gross Fair Value Commercial paper $ 368,778 $ 32 $ ( 67 ) $ 368,743 Corporate notes 16,758 — ( 15 ) 16,743 Corporate equity securities 20,167 — — 20,167 Total $ 405,703 $ 32 $ ( 82 ) $ 405,653 The amortized cost of marketable securities is adjusted for amortization of premiums and accretion of discounts to maturity. At March 31, 2022 , the balance in accumulated other comprehensive (loss) income was comprised solely of activity related to marketable securities. There were no realized gains or losses recognized on the sale or maturity of marketable securities for the three months ended March 31, 2022 and 2021 and, as a result, the Company did not reclassify any amounts out of accumulated other comprehensive (loss) income for the same periods. The Company holds debt securities of companies with high credit quality and has determined that there was no material change in the credit risk of any of its debt securities. The contractual maturity dates of all the investments are less than one year .

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	3 Months Ended
	Mar. 31, 2022
Payables and Accruals [Abstract]
Accrued Expenses and Other Current Liabilities	6. Accrued expenses and other current liabilities Accrued expenses and other current liabilities consist of the following (in thousands): March 31, December 31, Employee compensation and related benefits $ 6,771 $ 11,661 Research costs 6,545 3,133 Professional fees 3,542 3,330 Process development and manufacturing costs 2,299 3,833 Other 4,905 6,964 Total $ 24,062 $ 28,921

Leases

Leases	3 Months Ended
	Mar. 31, 2022
Leases [Abstract]
Leases	7. Leases Operating leases The Company’s operating leases are as follows: • A February 2018 lease for 38,203 square feet of office and laboratory space, which commenced in March 2018 and terminates in September 2028 . The lease is subject to fixed-rate rent escalations and provided for $ 6.1 million in tenant improvements and a term extension option, which is not reasonably certain of exercise. • An October 2018 lease for laboratory space as amended, which commenced in April 2019 and terminates in December 2025 . The amended lease is subject to fixed-rate rent escalations and provides an option to extend the lease for two additional two-year periods through December 31, 2029, which are not reasonably certain of being exercised. Through March 31, 2022, the Company has recorded right-of-use, or ROU assets and lease liabilities of $ 14.1 million and $ 14.0 million related to this lease. • An April 2019 lease for office and laboratory space, that was built over the course of 2020 and 2021. Pursuant to the terms of the original lease agreement, the first phase of the lease commenced in October 2020 (rent payments for the first phase began in August 2021 ) and the second phase of the lease commenced in January 2021 (rent payments for the second phase began in February 2022 ). The lease is subject to fixed-rate rent escalations and provides for $ 23.4 million in tenant improvements and the option to extend the lease for two terms of five years each, which are not reasonably certain of exercise. The Company determined that it is the accounting owner of all tenant improvements. The Company maintains a security deposit of $ 9.7 million in the form of a letter of credit, which is included in restricted cash as of March 31, 2022 and December 31, 2021 . Upon commencement of the first phase of this lease in October 2020, the Company recorded an operating lease ROU asset of $ 66.8 million and a lease liability of $ 68.8 million and upon commencement of the second phase of this lease in January 2021, the Company recorded an operating lease ROU asset of $ 22.0 million and a corresponding lease liability of $ 23.0 million. Subsequently, during the second quarter of 2021, the Company amended the rent commencement dates of the first and second phases of this lease. Pursuant to the terms of the amendment, the lease will terminate in February 2034 , which is 12 years from the amended second phase rent commencement date. As a result, the Company recorded an increase in the ROU asset of $ 0.5 million and lease liability of $ 0.5 million. The following table summarizes operating lease costs and sublease income (in thousands): Three Months Ended 2022 2021 Operating lease costs $ 4,386 $ 4,558 Variable lease costs 1,136 210 Short-term lease costs 232 — Sublease income ( 331 ) — Total $ 5,423 $ 4,768 The following table summarizes the lease term and discount rate for operating leases: March 31, December 31, Weighted-average remaining lease term (years) 10.6 11.1 Weighted-average discount rate 7.0 % 7.0 % The following table summarizes the lease costs for amounts included in the measurement of lease liabilities (in thousands): Three Months Ended 2022 2021 Operating cash flows used for operating leases $ 4,509 $ 1,685 Operating lease liabilities arising from obtaining ROU assets 4,822 23,366 At March 31, 2022, the future minimum lease payments for the Company’s operating leases for each of the next five years and total thereafter were as follows (in thousands): Remainder of 2022 $ 13,865 2023 19,006 2024 19,586 2025 20,066 2026 17,143 Thereafter 115,692 Undiscounted lease payments 205,358 Less: imputed interest ( 59,965 ) Total operating lease liabilities $ 145,393 In August 2020, the Company entered into a lease agreement with Alexandria Real Estate Equities, Inc., or the Landlord, to build a 100,000 square foot manufacturing facility in Research Triangle Park, North Carolina intended to support a broad range of clinical programs. The lease has a term of 15 years following the commencement date and provides the Company the option to extend the lease term for two five-year terms. It is subject to fixed rate escalation increases and also provides up to $ 20.0 million for reimbursement of tenant improvements. As the lease had not commenced as of March 31, 2022, the Company has not recorded an operating lease ROU asset or lease liability for this lease in the accompanying condensed consolidated balance sheets. The lease payments are subject to adjustment following the determination of the total project costs of the landlord. The initial estimate of the minimum amount of undiscounted lease payments due under this lease is $ 69.0 million. The Company anticipates that the facility will be operational in the first quarter of 2023 at which time it would begin making rent payments. The tabular disclosure of minimum lease payments above does not include payments due under this lease. In August 2021, the Company executed a lease amendment to its April 2019 lease for office and laboratory space in Cambridge, Massachusetts to occupy additional space. The term of this lease will run concurrent with the term of the April 2019 lease. The initial estimate of the minimum amount of undiscounted lease payments due under this lease is $ 11.1 million. As the lease had not yet commenced as of March 31, 2022 , the Company has not recorded an operating lease ROU asset or lease liability for this lease in the accompanying condensed consolidated balance sheets. The tabular disclosure of minimum lease payments above does not include payments due under this lease.

Guide Acquisition

Guide Acquisition	3 Months Ended
	Mar. 31, 2022
Business Combinations [Abstract]
Guide Acquisition	8. Guide acquisition On February 23, 2021 , the Company entered into the Guide Merger Agreement. Under the Guide Merger Agreement, the Company paid Guide’s former stockholders and optionholders upfront consideration in an aggregate amount of $ 120.0 million, excluding customary purchase price adjustments and closing costs, in shares of the Company’s common stock, based upon the volume-weighted average price of the Company’s stock over the ten trading day period ending on February 19, 2021. Pursuant to the Guide Merger Agreement, the Company acquired all of the issued and outstanding shares of Guide. The Company issued a total of 1,087,153 shares of its common stock valued at $ 120.0 million in connection with the upfront payment to Guide’s former stockholders and optionholders. The Guide transaction resulted in the acquisition of certain know-how and intellectual property assets related to Guide’s proprietary in vivo LNP screening technology and its library of lipids and lipid nanoparticle formulations identified using the screening technology. Management determined that the acquired assets do not meet the definition of a business pursuant to ASC 805, Business Combinations , as substantially all of the fair value of the acquired assets is concentrated into one identifiable asset, the LNP screening technology and associated lipid library. As of the date of closing of the transactions contemplated by the Guide Merger Agreement, or the Guide Merger Agreement Date, the asset acquired had no alternative future use and had not reached a stage of technological feasibility. As a result, all share-based and cash payment obligations have been recorded as research and development expense in the accompanying condensed consolidated statements of operations and other comprehensive loss in the amount of $ 155.0 million. The total transaction price was allocated to the assets acquired and liabilities assumed on a relative fair value basis. In addition, Guide’s former stockholders and optionholders are eligible to receive up to an additional $ 100.0 million in technology milestone payments and $ 220.0 million in product milestone payments, payable in the Company’s common stock valued using the volume-weighted average price of the Company’s stock over the ten trading-day period ending two trading days prior to the date on which the applicable milestone is received. The Company determined that all future technology and product milestone payments are classified as contingent consideration liabilities under ASC 480 and therefore the Company recorded a liability for these milestone payments as of the Guide Merger Agreement Date at fair value of $ 36.5 million. These contingent consideration liabilities are remeasured at fair value each financial reporting period, with the resulting impact reflected in the Company’s condensed consolidated statements of operations and other comprehensive loss, presented within other income (expense). The transaction price was determined and allocated as follows (in thousands): Transaction price Fair value of equity instruments issued $ 120,032 Technology and product contingent consideration liabilities 36,513 Transaction costs 2,531 Total transaction price $ 159,076 Transaction price allocated In-process research and development $ 154,953 Cash acquired 3,151 Prepaid expenses and other assets 264 Property and equipment 1,835 Assembled workforce 300 Other liabilities assumed ( 1,427 ) Total transaction price $ 159,076

License Agreements

License Agreements	3 Months Ended
	Mar. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
License Agreements	9. License agreements Harvard license agreement Under the Harvard License Agreement, Harvard is entitled to receive success payments, in cash or shares of Company stock, determined based upon the achievement of specified multiples of the initial weighted average value of the Company’s Series A Preferred Stock at specified valuation dates. The success payments range from $ 5.0 million to a maximum of $ 105.0 million and have valuation multiples that range from 5 times to 40 times the initial weighted average value of the Series A Preferred Stock. Subsequent to the Company’s IPO, the amount of success payments is based on the market value of the Company’s common stock. The Company is required to make success payments to Harvard during a period of time, or the Harvard Success Payment Period, which has been determined to be the later of (1) the ninth anniversary of the Harvard License Agreement or (2) the earlier of (a) the twelfth anniversary of the Harvard License Agreement and (b) the third anniversary of the first date on which a licensed product receives regulatory approval in the United States. During the Harvard Success Payment Period and beginning one year after the Company’s IPO, the Company will perform a calculation of any amounts owed to Harvard on each rolling 90-day period. In May 2021, the first success payment measurement occurred and amounts due to Harvard were calculated to be $ 15.0 million. The Company elected to make the payment in shares of the Company’s common stock and issued 174,825 shares of the Company’s common stock to settle this liability on June 10, 2021. The Company may owe Harvard success payments of up to an additional $ 90.0 million. As of March 31, 2022 , no success payments were due to Harvard. The following table summarizes the Company’s success payment liability for Harvard (in thousands): March 31, December 31, Harvard success payment liability $ 14,200 $ 21,000 The following table summarizes the expense resulting from the change in the fair value of the success payment liability for Harvard (in thousands): Three Months Ended March 31, 2022 2021 Change in fair value of Harvard success payment liability $ ( 6,800 ) $ 1,000 The annual maintenance fee under the Harvard License Agreement is recorded as research and development expense. Annual patent costs will be expensed as incurred. As of March 31, 2022, the Company determined that product development and regulatory approval milestones under the Harvard License Agreement were not probable and, as such, no amounts were recognized for the three months ended March 31, 2022. There was no expense recorded for these milestones for the three months ended March 31, 2021. During the three months ended March 31, 2022 the Company incurred $ 0.5 million of expense related to non-royalty sublicense fees owed to Harvard. As of March 31, 2022 , the Company has accrued $ 33.1 million of non-royalty sublicense fees owed to Harvard. Broad license agreement Under the Broad License Agreement, Broad Institute is entitled to receive success payments, in cash or shares of Company common stock, determined based upon the achievement of specified multiples of the initial weighted average value of the Series A Preferred Stock at specified valuation dates. The success payments range from $ 5.0 million to a maximum of $ 105.0 million and have valuation multiples that range from 5 times to 40 times the initial weighted average value of the Series A Preferred Stock. Subsequent to the Company's IPO, the amount of success payments is based on the market value of the Company’s common stock. The Company is required to make success payments to Broad Institute during a period of time, or the Broad Success Payment Period, which has been determined to be the earliest of (1) the twelfth anniversary of the Broad License Agreement or (2) the third anniversary of the first date on which a licensed product receives regulatory approval in the United States. During the Broad Success Payment Period and beginning one year after the Company’s IPO, the Company will perform a calculation of any amounts owed to Broad Institute on each rolling 90-day period. In May 2021, the first success payment measurement occurred and amounts due to Broad Institute were calculated to be $ 15.0 million. The Company elected to make the payment in shares of the Company’s common stock and issued 174,825 shares of the Company’s common stock to settle this liability on June 10, 2021. The Company may owe Broad Institute success payments of up to an additional $ 90.0 million. As of March 31, 2022 , no success payments were due to Broad Institute. The following table summarizes the Company’s success payment liability for Broad Institute (in thousands): March 31, December 31, Broad Institute success payment liability $ 14,400 $ 21,200 The following table summarizes the expense resulting from the change in the fair value of the success payment liability for Broad Institute (in thousands): Three Months Ended March 31, 2022 2021 Change in fair value of Broad Institute success payment liability $ ( 6,800 ) $ 900 The annual maintenance fee under the Broad License Agreement is recorded as research and development expense. Annual patent costs will be expensed as incurred. As of March 31, 2022, the Company determined that product development and regulatory approval milestones and royalties under the Broad License Agreement were not probable and, as such, no amounts were recognized for the three months ended March 31, 2022 . There was no expense recorded for these milestones for the three months ended March 31, 2021. The Company paid $ 6.1 million of non-royalty sublicense fees to Broad Institute during the three months ended March 31, 2022. Editas license agreement In May 2018, the Company entered into a license agreement, or the Editas License Agreement, with Editas Medicine, Inc., or Editas. Pursuant to the Editas License Agreement, Editas granted to the Company licenses and options to acquire licenses to certain intellectual property rights owned or controlled by Editas, for specified uses. The annual maintenance fees under the Editas License Agreement are recorded as research and development expense. Annual patent costs are expensed as incurred. In addition, the Company is required to make certain development, regulatory and commercial milestone payments to Editas upon the achievement of specified milestones. The Company recorded $ 0.1 million of expense related to these milestones during the three months ended March 31, 2022. Management concluded that the licenses acquired from each transaction above did not meet the accounting definition of a business as inputs, but no processes or outputs were acquired with the licenses, and the licensed technology had not achieved technological feasibility. As the inputs that were acquired along with the licenses do not constitute a “business,” the transactions have been accounted as asset acquisitions.

Collaboration and License Agree

Collaboration and License Agreements	3 Months Ended
	Mar. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Collaboration and License Agreements	10. Collaboration and license agreements Pfizer In December 2021, the Company entered into a research collaboration agreement, or the Pfizer Agreement, with Pfizer Inc., or Pfizer, focused on the use of certain of the Company’s base editing technology to develop in vivo therapies for rare genetic diseases of the liver, muscle, and central nervous system. Under the terms of the Pfizer Agreement, the Company will conduct all research activities through development candidate selection for three base editing programs that target specific genes corresponding to specific diseases that are the subject of such programs. Pfizer will have exclusive rights to license each of the three programs at no additional cost, each an Opt-In Right, and will assume responsibility for subsequent development and commercialization. At the end of the Phase 1/2 clinical trials, the Company may elect to enter into a global co-development and co-commercialization agreement with Pfizer with respect to one program licensed under the collaboration for an option exercise fee equal to a percentage of the applicable development costs incurred by Pfizer, or the Participation Election. In the event the Company elects to exercise its Participation Election, upon the payment of its option exercise fee, Pfizer and the Company would share net profits as well as development and commercialization costs in a 65 %/ 35 % (Pfizer/Company) split for such program. The research collaboration is managed on an overall basis by a Joint Research Committee, or JRC, formed by an equal number of representatives from the Company and Pfizer. At the inception of the Pfizer Agreement, the Company was entitled to receive a nonrefundable upfront payment of $ 300.0 million in consideration for the rights granted to Pfizer under the collaboration. Should Pfizer exercise its Opt-In Right for any of the three programs, the Company would be eligible to receive development, regulatory, and commercial milestones of up to $ 350.0 million per program, for potential total consideration of up to $ 1.35 billion, plus royalty payments on global net sales for each licensed program, if any. If Pfizer does not exercise its Opt-In Right for a program, the Company’s rights in such program revert to the Company and the Company will be required to pay Pfizer earn-out payments equal to a low single digit percentage of net sales earned on such program for a ten-year period, if any. As the $ 300.0 million upfront fee was not received by the Company as of December 31, 2021, the Company recorded a collaboration receivable for $ 300.0 million with a corresponding deferred revenue liability. The Company received the $ 300.0 million in January 2022. During the collaboration term, Pfizer has a one-time option to substitute a disease that is the subject of a specific program with one pre-defined substitute disease. The collaboration has an initial term of four years and may be extended for an additional year on a program-by-program basis. Pfizer may terminate the Pfizer Agreement for convenience on any or all of the programs by providing 90 days’ prior written notice. The Company accounts for the Pfizer Agreement under ASC 606, Revenue from Contracts with Customers , or ASC 606, as it includes a customer-vendor relationship as defined under ASC 606 and meets the criteria to be considered a contract. The overall transaction price as of the inception of the contract was determined to be $ 300.0 million, which is comprised entirely of the nonrefundable upfront payment. There is no variable consideration included in the transaction price at inception as the future milestone payments are fully constrained and the Company is not required to estimate variable consideration for the royalty payments at contract inception. The Company will re-evaluate the transaction price in each reporting period. The Company has concluded that the licenses to its base editing technology, including the exclusive development and commercialization rights, are not capable of being distinct from the other performance obligations, and as such the Company has determined that the licenses combined with the other research and development services represent performance obligations and no up-front revenue was recognized for the licenses. The selling price of each performance obligation was determined based on the Company’s estimated standalone selling price, or the ESSP. The Company developed the ESSP for all of the performance obligations included in the Pfizer Agreement with the objective of determining the price at which it would sell such an item if it were to be sold regularly on a standalone basis. The Company allocated the stand-alone selling price to the performance obligations based on the relative standalone selling price method. The Company recognizes revenue for each performance obligation as it is satisfied during the term of the agreement using an input method. The Company allocated the transaction price of $ 300.0 million to each of the three performance obligations, which includes each of the three base editing programs combined with the research and development services, licenses, and exclusive development and commercialization rights. Revenue is recognized using an input method based on the actual costs incurred as a percentage of total budgeted costs towards satisfying the performance obligation as this method provides the most faithful depiction of the entity’s performance in transferring control of the goods and services promised to Pfizer and represents the Company’s best estimate of the period of the obligation. For the three months ended March 31, 2022 , the Company recognized $ 6.3 million of revenue related to the Pfizer Agreement. As of March 31, 2022 , there is $ 95.6 million and $ 198.1 million of current and long-term deferred revenue, respectively, related to the Pfizer Agreement. Apellis Pharmaceuticals In June 2021, the Company entered into a research collaboration agreement, or the Apellis Agreement, with Apellis Pharmaceuticals, Inc., or Apellis, focused on the use of certain of the Company’s base editing technology to discover new treatments for complement system-driven diseases. Under the terms of the Apellis Agreement, the Company will conduct preclinical research on up to six base editing programs that target specific genes within the complement system in various organs, including the eye, liver, and brain. Apellis has an exclusive option to license any or all of the six programs, or in each case, an Opt-In Right, and will assume responsibility for subsequent development. The Company may elect to enter into a 50-50 U.S. co-development and co-commercialization agreement with Apellis with respect to one program instead of a license. The collaboration is managed on an overall basis by an alliance steering committee formed by an equal number of representatives from the Company and Apellis. As part of the collaboration, the Company is eligible to receive a total of $ 75.0 million in upfront and near-term milestones from Apellis, which is comprised of $ 50.0 million received upon signing and an additional $ 25.0 million payment on June 30, 2022, the one-year anniversary of the effective date of the Apellis Agreement, or the First Anniversary Payment. Following any exercise of an Opt-In Right for any of the six programs, the Company will be eligible to receive development, regulatory, and sales milestones from Apellis, as well as royalty payments on sales. The collaboration has an initial term of five years and may be extended up to two years on a per year and program-by-program basis. During the collaboration term, Apellis may, subject to certain limitations, substitute a specific complement gene and/or organ for any of the initial base editing programs. Apellis may terminate the Apellis Agreement for convenience on any or all of the programs by providing prior written notice. The Company received the $ 50.0 million upfront payment from Apellis in July 2021. The Company accounts for the Apellis Agreement under ASC 606 as it includes a customer-vendor relationship as defined under ASC 606 and meets the criteria to be considered a contract. The overall transaction price as of the inception of the contract was determined to be $ 75.0 million, which is composed of the upfront payment of $ 50.0 million and the First Anniversary Payment of $ 25.0 million. The Company will re-evaluate the transaction price in each reporting period. The $ 25.0 million for the First Anniversary Payment represents both a contract asset and a contract liability and the Company has presented these amounts net in accordance with ASC 606 guidance for contract assets and liabilities. The Company concluded that each of the six base editing programs combined with the research and development service, licenses, substitution rights and governance participation were material promises that were both capable of being distinct and were distinct within the context of the Apellis Agreement and represented separate performance obligations. Therefore, the Company did no t recognize any upfront revenue related to the license. The Company further concluded that the Opt-In Rights and option to extend the collaboration term did not grant Apellis a material right. The Company determined that the term of the contract is five years , as this is the period during which both parties have enforceable rights. The selling price of each performance obligation was determined based on the Company’s estimated standalone selling price, or the ESSP. The Company developed the ESSP for all of the performance obligations included in the Apellis Agreement with the objective of determining the price at which it would sell such an item if it were to be sold regularly on a standalone basis. The Company allocated the stand-alone selling price to the performance obligations based on the relative standalone selling price method. The Company recognizes revenue for each performance obligation as it is satisfied over the five-year term using an input method. The Company allocated the transaction price of $ 75.0 million to each of the six performance obligations, which includes each of the six base editing programs combined with the research and development service, licenses, substitution rights and governance participation, and is being recognized using an input method based on the actual costs incurred as a percentage of total budgeted costs towards satisfying the performance obligation as this method provides the most faithful depiction of the entity’s performance in transferring control of the goods and services promised to Apellis and represents the Company’s best estimate of the period of the obligation. For the three months ended March 31, 2022 , the Company recognized $ 2.1 million of revenue related to the Apellis Agreement. As of March 31, 2022 , there is $ 19.4 million and $ 26.7 million of current and long-term deferred revenue, respectively, related to the Apellis Agreement. Prime Medicine In September 2019, the Company entered into a collaboration and license agreement, or the Prime Agreement, with Prime Medicine, Inc., or Prime, to research and develop a novel gene editing technology developed by one of the Company’s founders. Under the terms of the agreement, the Company granted Prime Medicine a non-exclusive license to certain of its CRISPR technology (including Cas12b), delivery technology and certain other technology controlled by the Company to develop and commercialize gene editing products for the treatment of human diseases. Prime Medicine granted the Company an exclusive license to develop and commercialize prime gene editing technology for the creation or modification of any single base transition mutations, as well as any edits made for the treatment of sickle cell disease. Additionally, each party granted to the other party certain exclusive and non-exclusive licenses to certain technology developed after the effective date of the agreement and controlled by the granting party or jointly owned by the parties. Each party has an obligation to assign rights in certain technology developed under the collaboration to the other party. The Company provided immaterial interim management and startup services to Prime Medicine through March 2021 but did not provide any services during 2022. As of March 31, 2022, the Company determined that future milestones and royalties under the Prime Agreement were not probable of recognition. Verve In April 2019, the Company entered into a collaboration and license agreement with Verve, or the Verve Agreement, to investigate gene editing strategies to modify genes associated with an increased risk of coronary diseases. Under the terms of the Verve Agreement, the Company granted Verve an exclusive license to certain base editor technology and certain delivery technology, and improvements and Verve granted Beam a non-exclusive license under certain know-how and patents controlled by Verve, an interest in joint collaboration technology and an exclusive license (except as to Verve) under certain delivery technology. As of March 31, 2022 , the Company determined that milestones and royalties under the Verve Agreement were not probable of recognition.

Common Stock

Common Stock	3 Months Ended
	Mar. 31, 2022
Stockholders' Equity Attributable to Parent [Abstract]
Common Stock	11. Common stock In January 2021, the Company issued and sold 2,795,700 shares of its common stock in a private placement at an offering price of $ 93.00 per share for aggregate gross proceeds of $ 260.0 million. The Company received $ 252.0 million in net proceeds after deducting fees to the placement agents and offering expenses payable by the Company. In April 2021, the Company entered into the Sales Agreement, with Jefferies, pursuant to which the Company was entitled to offer and sell, from time to time at prevailing market prices, shares of the Company’s common stock having aggregate gross proceeds of up to $ 300.0 million. The Company agreed to pay Jefferies a commission of up to 3.0 % of the aggregate gross sale proceeds of any shares sold by Jefferies under the Sales Agreement. Between April and July 2021, the Company has sold 2,908,009 shares of its common stock under the Sales Agreement at an average price of $ 103.16 per share for aggregate gross proceeds of $ 300.0 million, before deducting commissions and offering expenses payable by the Company. In July 2021, the Company and Jefferies entered into an amendment to the Sales Agreement to provide for an increase in the aggregate offering amount under the Sales Agreement, such that as of July 7, 2021, the Company may offer and sell shares of common stock having an aggregate offering price of an additional $ 500.0 million. As of March 31, 2022, the Company has sold 2,873,956 additional shares of its common stock under the amended Sales Agreement at an average price of $ 92.71 per share for aggregate gross proceeds of $ 266.5 million, before deducting commissions and offering expenses payable by the Company. The holders of the Company’s common stock are entitled to one vote for each share of common stock. Subject to the payment in full of all preferential dividends to which the holders of the Company’s preferred stock are entitled, the holders of the Company’s common stock shall be entitled to receive ratably dividends out of funds legally available. In the event of any voluntary or involuntary liquidation, dissolution, or winding up of the Company, after the payment or provision for payment of all debts and liabilities of the Company and all preferential amounts to which the holders of Company’s preferred stock are entitled with respect to the distribution of assets in liquidation, the holders of common stock shall be entitled to share ratably in the remaining assets of the Company available for distribution.

Stock Option and Grant Plan

Stock Option and Grant Plan	3 Months Ended
	Mar. 31, 2022
Share-based Payment Arrangement [Abstract]
Stock Option and Grant Plan	12. Stock option and grant plan 2017 stock option and grant plan In June 2017, the Company’s board of directors adopted the Beam Therapeutics Inc. 2017 Stock Option and Grant Plan, or the 2017 Plan, which provided for the grant of qualified incentive stock options and nonqualified stock options, restricted stock or other awards to the Company’s employees, officers, directors, advisors, and outside consultants for the issuance or purchase of shares of the Company’s common stock. In May 2019, the 2017 Plan was amended to provide up to 8,078,681 shares of common stock for the issuance of stock options and restricted stock. 2019 equity incentive plan In October 2019, the Company’s board of directors adopted the Beam Therapeutics Inc. 2019 Equity Incentive Plan, or the 2019 Plan, and, following the IPO, all equity-based awards have been granted under the 2019 Plan. The 2019 Plan provides for the grant of qualified and nonqualified stock options, stock appreciation rights, restricted and unrestricted stock and stock units, performance awards, and other share-based awards to the Company’s employees, officers, directors, advisors, and outside consultants. The maximum number of shares of the Company’s common stock that may be issued under the 2019 Plan was initially 3,700,000 shares, or the Share Pool, plus the number of shares of the Company’s common stock underlying awards under the 2017 Plan, not to exceed 5,639,818 shares, that become available again for grant under the 2017 Plan in accordance with its terms. The Share Pool will automatically increase on January 1st of each year from 2021 to 2029 by the lesser of (i) four percent of the number of shares of the Company’s common stock outstanding as of the close of business on the immediately preceding December 31st and (ii) the number of shares determined by the Company’s board of directors on or prior to such date for such year. As of March 31, 2022, the Company had 11,226,843 shares reserved including 2,452,727 shares available for future issuance pursuant to the 2019 Plan. Stock-based compensation expense recorded as research and development and general and administrative expenses in the condensed consolidated statements of operations and other comprehensive loss is as follows (in thousands): Three Months Ended 2022 2021 Research and development $ 11,294 $ 3,155 General and administrative 6,741 1,493 Total stock-based compensation expense $ 18,035 $ 4,648 Stock options The following table provides a summary of option activity under the Company’s equity award plans : Number Weighted Outstanding at December 31, 2021 6,034,192 $ 32.40 Granted 1,427,500 69.13 Exercised ( 176,652 ) 4.64 Forfeitures ( 20,637 ) 36.41 Outstanding at March 31, 2022 7,264,403 40.28 Exercisable as of March 31, 2022 2,602,709 $ 15.83 The weighted-average grant date fair value per share of options granted in the three months ended March 31, 2022 was $ 46.09 . As of March 31, 2022, there was $ 158.4 million of unrecognized compensation expense related to unvested stock options, which is expected to be recognized over a weighted-average period of approximately 2.6 years. Restricted stock The Company issues shares of restricted common stock, including both restricted stock units and restricted stock awards. Restricted common stock issued generally vests over a period of two to four years . The following table summarizes the Company’s restricted stock activity: Shares Weighted- Unvested as of December 31, 2021 1,126,206 $ 74.32 Issued 711,025 57.30 Vested ( 283,186 ) 38.69 Forfeited ( 11,519 ) 86.15 Unvested as of March 31, 2022 1,542,526 $ 72.93 At March 31, 2022, there was approximately $ 106.9 million of unrecognized stock-based compensation expense related to restricted stock that is expected to vest. These costs are expected to be recognized over a weighted-average remaining vesting period of approximately 3.5 years. 2019 employee stock purchase plan In February 2020, the Company’s board of directors adopted the Beam Therapeutics Inc. 2019 Employee Stock Purchase Plan, or ESPP, which was approved by the Company’s stockholders. Pursuant to the ESPP, certain employees of the Company, excluding consultants and non-employee directors, are eligible to purchase common stock of the Company at a reduced rate during offering periods. The ESPP permits participants to purchase common stock using funds contributed through payroll deductions, subject to a calendar year limit of $ 25,000 and at a purchase price of 85 % of the lower of the fair market value of the Company’s common stock on the first trading day of the offering period or on the applicable purchase date, which will be the final trading day of the applicable purchase period. The first offering period commenced on October 1, 2021 . The Company issued 28,990 shares under the ESPP during the three months ended March 31, 2022. There were no shares issued under the ESPP during the three months ended March 31, 2021. As of March 31, 2022 , the Company had 1,706,282 shares available for issuance under the ESPP. The Company uses the straight-line attribution approach to record the expense over the offering period. Stock-based compensation for the ESPP for the three months ended March 31, 2022 was $ 0.3 million. There was no stock-based compensation expense recorded under the ESPP for the three months ended March 31, 2021 .

Net Loss per Share

Net Loss per Share	3 Months Ended
	Mar. 31, 2022
Earnings Per Share [Abstract]
Net Loss per Share	13. Net loss per share As noted above, for periods in which the Company reports a net loss, potentially dilutive securities have been excluded from the computation of diluted net loss per share as their effects would be anti-dilutive. Therefore, the weighted average number of common shares outstanding used to calculate both basic and diluted net loss per share is the same. The Company excluded the following potential common shares, presented based on amounts outstanding at period end, from the computation of diluted net loss per share because including them would have had an anti-dilutive effect: As of March 31, 2022 2021 Unvested restricted stock 1,542,526 1,388,114 Outstanding options to purchase common stock 7,264,403 6,108,126 Total 8,806,929 7,496,240 The following table summarizes the computation of basic and diluted net loss per share of the Company (in thousands, except share and per share amounts): Three Months Ended March 31, 2022 2021 Numerator: Net loss $ ( 69,214 ) $ ( 201,560 ) Denominator: Weighted average common shares outstanding, basic and diluted 68,703,864 60,210,120 Net loss per common share, basic and diluted $ ( 1.01 ) $ ( 3.35 )

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2022
Income Tax Disclosure [Abstract]
Income Taxes	14. Income taxes During the three months ended March 31, 2022 and 2021 , the Company recorded a full valuation allowance on federal and state deferred tax assets since management does not forecast the Company to be in a taxable position in the near future.

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2022
Related Party Transactions [Abstract]
Related Party Transactions	15. Related party transactions Founders The Company made payments of $ 0.1 million and $ 0.1 million to its three founder shareholders for scientific consulting and other expenses for the three months ended March 31, 2022 and 2021, respectively. Verve The Company and Verve are parties to a collaboration and license agreement and have a common board member. Prior to Verve’s initial public offering in June 2021, the Company owned both common and preferred shares of Verve and valued such investment based on the cost of the equity securities adjusted for any observable market transactions. Following Verve’s initial public offering, and the conversion of the preferred stock to common stock and a stock split, the equity securities have a readily determinable fair value and the Company owned 546,970 shares of Verve's common stock, the value of which is included in marketable securities in the condensed consolidated balance sheet. The Company recorded the investment at fair value as of March 31, 2022, which resulted in a recognition of other expense of $ 7.7 millio n during the three months ended March 31, 2022 . The Company recorded other income of $ 1.0 million for the three months ended March 31, 2021 related to the changes in fair value of Verve's stock. The value of this investment as of March 31, 2022 is $ 12.5 million. The Company purchased certain materials from Verve amounting to $ 0.2 million, which are recorded as research and development expenses within the accompanying condensed consolidated statements of operations and other comprehensive loss, for the three months ended March 31, 2021. The Company did no t purchase any materials from Verve during the three months ended March 31, 2022. In October 2021, the Company entered into an agreement pursuant to which Verve subleased 12,000 square feet of the Company’s existing office and laboratory space for a term of one year which began in December 2021 . Verve is expected to pay approximately $ 1.4 million in rental payments over the term of the sublease, as well as its proportionate costs for the landlord’s operating expense, insurance, property taxes, and utilities. The Company recorded $ 0.3 million of sublease income related to this sublease within the accompanying consolidated statements of operations and other comprehensive loss for the three months ended March 31, 2022. Prime Medicine The Company and Prime Medicine are parties to the Prime Agreement and have a common founder and a common board member. Additionally, in September 2019, in connection with the Prime Agreement, the Company executed a letter agreement, as amended, to provide certain interim management and startup services to Prime Medicine through March 2021. Prime Medicine was obligated to reimburse the Company’s out-of-pocket costs incurred in connection with performing these services and, beginning in October 2020 and ending in March 2021, paid the Company a $ 30.0 thousand monthly service fee. There were no interim management and startup services provided to Prime Medicine during the three months ended March 31, 2022.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation	Basis of presentation The accompanying condensed consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles, or GAAP. Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification, or ASC, and Accounting Standards Update, or ASU, of the Financial Accounting Standards Board, or FASB.
Principles of Consolidation	Principles of consolidation The accompanying condensed consolidated financial statements include the results of operations of the Company and its wholly-owned subsidiaries. All intercompany transactions and balances have been eliminated in consolidation.
Use of Estimates	Use of estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, and the disclosure of contingent assets and liabilities as of and during the reporting period. The Company bases its estimates and assumptions on historical experience when available and on various factors that it believes to be reasonable under the circumstances. Significant estimates and assumptions reflected in these condensed consolidated financial statements include, but are not limited to, incremental borrowing rate used in the calculation of lease liabilities, research and development expenses, stock-based compensation, contingent consideration liabilities, success payments and certain judgements regarding revenue recognition. Actual results could differ from these estimates.
Cash, Cash Equivalents, and Restricted Cash	Cash, cash equivalents, and restricted cash Cash and cash equivalents consist of standard checking accounts, money market accounts, and all highly liquid investments with a remaining maturity of three months or less at the date of purchase. Restricted cash represents collateral provided for letters of credit issued as security deposits in connection with the Company’s leases of its corporate and manufacturing facilities. The following table reconciles cash, cash equivalents, and restricted cash reported within the Company’s condensed consolidated balance sheets to the total of the amounts shown in the condensed consolidated statements of cash flows (in thousands): March 31, March 31, Cash and cash equivalents $ 296,821 $ 97,241 Restricted cash 12,746 14,840 Total cash, cash equivalents, and restricted cash $ 309,567 $ 112,081

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
Reconciliation of Cash, Cash Equivalents, and Restricted Cash	The following table reconciles cash, cash equivalents, and restricted cash reported within the Company’s condensed consolidated balance sheets to the total of the amounts shown in the condensed consolidated statements of cash flows (in thousands): March 31, March 31, Cash and cash equivalents $ 296,821 $ 97,241 Restricted cash 12,746 14,840 Total cash, cash equivalents, and restricted cash $ 309,567 $ 112,081

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	3 Months Ended
	Mar. 31, 2022
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment	Property and equipment consist of the following (in thousands): March 31, December 31, Leasehold improvements $ 58,041 $ 57,760 Lab equipment 35,489 29,905 Furniture and fixtures 3,699 3,679 Computer equipment 1,866 1,646 Construction in process 14,527 7,349 Total property and equipment 113,622 100,339 Less accumulated depreciation ( 19,334 ) ( 16,081 ) Property and equipment, net $ 94,288 $ 84,258
Summary of Depreciation Expense Incurred	The following table summarizes depreciation expense incurred (in thousands): Three Months Ended March 31, 2022 2021 Depreciation expense $ 3,262 $ 1,398

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2022
Schedule of Fair Value of Financial Assets and Liabilities	The following tables set forth the fair value of the Company’s financial assets and liabilities by level within the fair value hierarchy at March 31, 2022 (in thousands): Carrying Fair Level 1 Level 2 Level 3 Assets Cash equivalents: Money market funds $ 152,020 $ 152,020 $ 152,020 $ — $ — Commercial paper 144,801 144,801 — 144,801 — Marketable securities: Commercial paper 730,967 730,967 — 730,967 — Corporate notes 18,125 18,125 — 18,125 — U.S. Treasury securities 164,205 164,205 — 164,205 — Equity securities included in marketable securities: Corporate equity securities 12,482 12,482 12,482 — — Total assets $ 1,222,600 $ 1,222,600 $ 164,502 $ 1,058,098 $ — Liabilities Success payment liability – Harvard $ 14,200 $ 14,200 $ — $ — $ 14,200 Success payment liability – Broad Institute 14,400 14,400 — — 14,400 Contingent consideration liability – Technology 24,531 24,531 $ — $ — $ 24,531 Contingent consideration liability – Product 6,384 6,384 — — 6,384 Total liabilities $ 59,515 $ 59,515 $ — $ — $ 59,515 The following tables set forth the fair value of the Company’s financial assets and liabilities by level within the fair value hierarchy at December 31, 2021 (in thousands): Carrying Fair Level 1 Level 2 Level 3 Assets Cash equivalents: Money market funds $ 540,094 $ 540,094 $ 540,094 $ — $ — Commercial paper 13,997 13,997 — 13,997 — Corporate notes 5,903 5,903 — 5,903 — Marketable securities: Commercial paper 368,743 368,743 — 368,743 — Corporate notes 16,743 16,743 — 16,743 — Equity securities included in marketable securities Corporate equity securities 20,167 20,167 20,167 — — Total assets $ 965,647 $ 965,647 $ 560,261 $ 405,386 $ — Liabilities Success payment liability – Harvard $ 21,000 $ 21,000 $ — $ — $ 21,000 Success payment liability – Broad Institute 21,200 21,200 — — 21,200 Contingent consideration liability – Technology 24,359 $ 24,359 — — 24,359 Contingent consideration liability – Product 7,008 7,008 — — 7,008 Total liabilities $ 73,567 $ 73,567 $ — $ — $ 73,567
Success Payment Liabilities
Schedule of Variables Included in Calculation of Estimated Fair Value	The following variables were incorporated in the calculation of the estimated fair value of the Harvard and Broad Institute success payment liabilities: Harvard Broad Institute March 31, December 31, March 31, December 31, Fair value of common stock (per share) $ 57.30 $ 79.69 $ 57.30 $ 79.69 Expected volatility 80 % 76 % 80 % 76 % Expected term (years) 0.10 - 7.25 0.10 - 7.49 0.10 - 8.11 0.10 - 8.36
Schedule of change in Fair Value of Liabilities based on Level 3 inputs	The following table reconciles the change in the fair value of success payment liabilities based on Level 3 inputs (in thousands): Three Months Ended March 31, 2022 Harvard Broad Institute Total Balance at December 31, 2021 $ 21,000 $ 21,200 $ 42,200 Change in fair value ( 6,800 ) ( 6,800 ) ( 13,600 ) Balance at March 31, 2022 $ 14,200 $ 14,400 $ 28,600
Contingent Consideration Liabilities
Schedule of Variables Included in Calculation of Estimated Fair Value	The following variables were incorporated in the calculation of the estimated fair value of the contingent consideration liabilities: Technology Milestones Product Milestones March 31, December 31, March 31, December 31, Discount Rate 8.50 % 7.50 % 8.50 % 7.50 % Probability of Achievement 10 - 75 % 10 - 75 % 2 - 15 % 2 - 15 % Projected Year of Achievement 2022 - 2023 2022 - 2023 2024 - 2029 2023 - 2029
Schedule of change in Fair Value of Liabilities based on Level 3 inputs	The following table reconciles the change in fair value of the contingent consideration liabilities based on level 3 inputs (in thousands): Three Months Ended March 31, 2022 Technology Milestones Product Milestones Total Balance at December 31, 2021 $ 24,359 $ 7,008 $ 31,367 Change in fair value 172 ( 624 ) ( 452 ) Balance at March 31, 2022 $ 24,531 $ 6,384 $ 30,915

Marketable Securities (Tables)

Marketable Securities (Tables)	3 Months Ended
	Mar. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Summary of Marketable Securities Held	The following table summarizes the Company’s marketable securities held at March 31, 2022 (in thousands): Amortized Cost Gross Gross Fair Value Commercial paper $ 733,068 $ — $ ( 2,101 ) $ 730,967 Corporate notes 18,249 — ( 124 ) 18,125 U.S. Treasury securities 164,689 2 ( 486 ) 164,205 Corporate equity securities 12,482 — — 12,482 Total $ 928,488 $ 2 $ ( 2,711 ) $ 925,779 The following table summarizes the Company’s marketable securities held at December 31, 2021 (in thousands): Amortized Cost Gross Gross Fair Value Commercial paper $ 368,778 $ 32 $ ( 67 ) $ 368,743 Corporate notes 16,758 — ( 15 ) 16,743 Corporate equity securities 20,167 — — 20,167 Total $ 405,703 $ 32 $ ( 82 ) $ 405,653

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	3 Months Ended
	Mar. 31, 2022
Payables and Accruals [Abstract]
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consist of the following (in thousands): March 31, December 31, Employee compensation and related benefits $ 6,771 $ 11,661 Research costs 6,545 3,133 Professional fees 3,542 3,330 Process development and manufacturing costs 2,299 3,833 Other 4,905 6,964 Total $ 24,062 $ 28,921

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2022
Leases [Abstract]
Summary of Operating Lease Costs	The following table summarizes operating lease costs and sublease income (in thousands): Three Months Ended 2022 2021 Operating lease costs $ 4,386 $ 4,558 Variable lease costs 1,136 210 Short-term lease costs 232 — Sublease income ( 331 ) — Total $ 5,423 $ 4,768
Summary of Lease Term and Discount Rate	The following table summarizes the lease term and discount rate for operating leases: March 31, December 31, Weighted-average remaining lease term (years) 10.6 11.1 Weighted-average discount rate 7.0 % 7.0 %
Summary of Lease Costs for Amounts Included in Measurement of Lease Liabilities	The following table summarizes the lease costs for amounts included in the measurement of lease liabilities (in thousands): Three Months Ended 2022 2021 Operating cash flows used for operating leases $ 4,509 $ 1,685 Operating lease liabilities arising from obtaining ROU assets 4,822 23,366
Summary of Future Minimum Lease Payments of Operating Leases	At March 31, 2022, the future minimum lease payments for the Company’s operating leases for each of the next five years and total thereafter were as follows (in thousands): Remainder of 2022 $ 13,865 2023 19,006 2024 19,586 2025 20,066 2026 17,143 Thereafter 115,692 Undiscounted lease payments 205,358 Less: imputed interest ( 59,965 ) Total operating lease liabilities $ 145,393

Guide Acquisition (Tables)

Guide Acquisition (Tables)	3 Months Ended
	Mar. 31, 2022
Business Combinations [Abstract]
Summary of Transaction Price Determined and Allocated	The transaction price was determined and allocated as follows (in thousands): Transaction price Fair value of equity instruments issued $ 120,032 Technology and product contingent consideration liabilities 36,513 Transaction costs 2,531 Total transaction price $ 159,076 Transaction price allocated In-process research and development $ 154,953 Cash acquired 3,151 Prepaid expenses and other assets 264 Property and equipment 1,835 Assembled workforce 300 Other liabilities assumed ( 1,427 ) Total transaction price $ 159,076

License Agreements (Tables)

License Agreements (Tables)	3 Months Ended
	Mar. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Success Payment Liability	The following table summarizes the Company’s success payment liability for Harvard (in thousands): March 31, December 31, Harvard success payment liability $ 14,200 $ 21,000 The following table summarizes the Company’s success payment liability for Broad Institute (in thousands): March 31, December 31, Broad Institute success payment liability $ 14,400 $ 21,200
Schedule of Change in Fair Value of Success Payment Liability	The following table summarizes the expense resulting from the change in the fair value of the success payment liability for Harvard (in thousands): Three Months Ended March 31, 2022 2021 Change in fair value of Harvard success payment liability $ ( 6,800 ) $ 1,000 The following table summarizes the expense resulting from the change in the fair value of the success payment liability for Broad Institute (in thousands): Three Months Ended March 31, 2022 2021 Change in fair value of Broad Institute success payment liability $ ( 6,800 ) $ 900

Stock Option and Grant Plan (Ta

Stock Option and Grant Plan (Tables)	3 Months Ended
	Mar. 31, 2022
Share-based Payment Arrangement [Abstract]
Summary of Stock-based Compensation Expense	Stock-based compensation expense recorded as research and development and general and administrative expenses in the condensed consolidated statements of operations and other comprehensive loss is as follows (in thousands): Three Months Ended 2022 2021 Research and development $ 11,294 $ 3,155 General and administrative 6,741 1,493 Total stock-based compensation expense $ 18,035 $ 4,648
Summary of Option Activity Under Equity Award Plans	: Number Weighted Outstanding at December 31, 2021 6,034,192 $ 32.40 Granted 1,427,500 69.13 Exercised ( 176,652 ) 4.64 Forfeitures ( 20,637 ) 36.41 Outstanding at March 31, 2022 7,264,403 40.28 Exercisable as of March 31, 2022 2,602,709 $ 15.83
Summary of Restricted Stock Activity	The following table summarizes the Company’s restricted stock activity: Shares Weighted- Unvested as of December 31, 2021 1,126,206 $ 74.32 Issued 711,025 57.30 Vested ( 283,186 ) 38.69 Forfeited ( 11,519 ) 86.15 Unvested as of March 31, 2022 1,542,526 $ 72.93

Net Loss per Share (Tables)

Net Loss per Share (Tables)	3 Months Ended
	Mar. 31, 2022
Earnings Per Share [Abstract]
Schedule of Potential Common Shares Excluded from Computation of Diluted Net Loss per Share	The Company excluded the following potential common shares, presented based on amounts outstanding at period end, from the computation of diluted net loss per share because including them would have had an anti-dilutive effect: As of March 31, 2022 2021 Unvested restricted stock 1,542,526 1,388,114 Outstanding options to purchase common stock 7,264,403 6,108,126 Total 8,806,929 7,496,240
Summary of Computation of Basic and Diluted Net Loss per Share	The following table summarizes the computation of basic and diluted net loss per share of the Company (in thousands, except share and per share amounts): Three Months Ended March 31, 2022 2021 Numerator: Net loss $ ( 69,214 ) $ ( 201,560 ) Denominator: Weighted average common shares outstanding, basic and diluted 68,703,864 60,210,120 Net loss per common share, basic and diluted $ ( 1.01 ) $ ( 3.35 )

Nature of the Business and Ba_2

Nature of the Business and Basis of Presentation - Additional Information (Details) - USD ($)	1 Months Ended	3 Months Ended	4 Months Ended
	Apr. 30, 2021	Mar. 31, 2022	Jul. 31, 2021	Dec. 31, 2021	Jul. 07, 2021
Nature Of Business And Basis Of Presentation [Line Items]
Accumulated deficit		$ 837,488,000		$ 768,274,000
Cash, cash equivalents, and marketable securities		1,200,000,000
Jeffries LLC Amended Sales Agreement
Nature Of Business And Basis Of Presentation [Line Items]
Gross proceeds from issuance of common stock		$ 266,500,000
Jeffries LLC Amended Sales Agreement | Common Stock
Nature Of Business And Basis Of Presentation [Line Items]
Stock sold during period shares, new issues		2,873,956
Public offering price per share		$ 92.71
Jeffries LLC Amended Sales Agreement | At-The-Market
Nature Of Business And Basis Of Presentation [Line Items]
Aggregate gross proceeds of shares authorized under ATM sales agreement					$ 500,000,000
Jeffries LLC Sales Agreement
Nature Of Business And Basis Of Presentation [Line Items]
Gross proceeds from issuance of common stock		$ 300,000,000
Jeffries LLC Sales Agreement | Common Stock
Nature Of Business And Basis Of Presentation [Line Items]
Stock sold during period shares, new issues			2,908,009
Public offering price per share			$ 103.16
Jeffries LLC Sales Agreement | Maximum | At-The-Market
Nature Of Business And Basis Of Presentation [Line Items]
Commission rate	3.00%
Aggregate gross proceeds of shares authorized under ATM sales agreement	$ 300,000,000

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Reconciliation of Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Cash and cash equivalents	$ 296,821	$ 559,994	$ 97,241
Restricted cash	12,746	12,746	14,840
Total cash, cash equivalents, and restricted cash	$ 309,567	$ 572,740	$ 112,081	$ 177,011

Property and Equipment, Net - S

Property and Equipment, Net - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Property Plant And Equipment [Line Items]
Total property and equipment	$ 113,622	$ 100,339
Less accumulated depreciation	(19,334)	(16,081)
Property and equipment, net	94,288	84,258
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total property and equipment	58,041	57,760
Lab Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	35,489	29,905
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Total property and equipment	3,699	3,679
Computer Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	1,866	1,646
Construction in Process
Property Plant And Equipment [Line Items]
Total property and equipment	$ 14,527	$ 7,349

Property and Equipment, Net -_2

Property and Equipment, Net - Summary of Depreciation Expense Incurred (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 3,262	$ 1,398

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - Schedule of Fair Value of Financial Assets and Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Commercial Paper
Assets
Marketable securities	$ 730,967	$ 368,743
Harvard
Liabilities
Success payment liability	14,200	21,000
Broad Institute
Liabilities
Success payment liability	14,400	21,200
Recurring | Carrying Amount
Assets
Total assets	1,222,600	965,647
Liabilities
Total liabilities	59,515	73,567
Recurring | Carrying Amount | Money Market Funds
Assets
Cash equivalents	152,020	540,094
Recurring | Carrying Amount | Commercial Paper
Assets
Cash equivalents	144,801	13,997
Marketable securities	730,967	368,743
Recurring | Carrying Amount | Corporate Notes
Assets
Cash equivalents		5,903
Marketable securities	18,125	16,743
Recurring | Carrying Amount | U.S. Treasury Securities
Assets
Marketable securities	164,205
Recurring | Carrying Amount | Corporate Equity Securities
Assets
Equity securities included in marketable securities	12,482	20,167
Recurring | Carrying Amount | Consideration of Technology Liabilities
Liabilities
Contingent consideration liability	24,531	24,359
Recurring | Carrying Amount | Contingent Consideration of Product Liabilities
Liabilities
Contingent consideration liability	6,384	7,008
Recurring | Fair Value
Assets
Total assets	1,222,600	965,647
Liabilities
Total liabilities	59,515	73,567
Recurring | Fair Value | Money Market Funds
Assets
Cash equivalents	152,020	540,094
Recurring | Fair Value | Commercial Paper
Assets
Cash equivalents	144,801	13,997
Marketable securities	730,967	368,743
Recurring | Fair Value | Corporate Notes
Assets
Cash equivalents		5,903
Marketable securities	18,125	16,743
Recurring | Fair Value | U.S. Treasury Securities
Assets
Marketable securities	164,205
Recurring | Fair Value | Corporate Equity Securities
Assets
Equity securities included in marketable securities	12,482	20,167
Recurring | Fair Value | Consideration of Technology Liabilities
Liabilities
Contingent consideration liability	24,531	24,359
Recurring | Fair Value | Contingent Consideration of Product Liabilities
Liabilities
Contingent consideration liability	6,384	7,008
Recurring | Fair Value | Level 1
Assets
Total assets	164,502	560,261
Recurring | Fair Value | Level 1 | Money Market Funds
Assets
Cash equivalents	152,020	540,094
Recurring | Fair Value | Level 1 | Corporate Equity Securities
Assets
Equity securities included in marketable securities	12,482	20,167
Recurring | Fair Value | Level 2
Assets
Total assets	1,058,098	405,386
Recurring | Fair Value | Level 2 | Commercial Paper
Assets
Cash equivalents	144,801	13,997
Marketable securities	730,967	368,743
Recurring | Fair Value | Level 2 | Corporate Notes
Assets
Cash equivalents		5,903
Marketable securities	18,125	16,743
Recurring | Fair Value | Level 2 | U.S. Treasury Securities
Assets
Marketable securities	164,205
Recurring | Fair Value | Level 3
Liabilities
Total liabilities	59,515	73,567
Recurring | Fair Value | Level 3 | Consideration of Technology Liabilities
Liabilities
Contingent consideration liability	24,531	24,359
Recurring | Fair Value | Level 3 | Contingent Consideration of Product Liabilities
Liabilities
Contingent consideration liability	6,384	7,008
Recurring | Harvard | Carrying Amount
Liabilities
Success payment liability	14,200	21,000
Recurring | Harvard | Fair Value
Liabilities
Success payment liability	14,200	21,000
Recurring | Harvard | Fair Value | Level 3
Liabilities
Success payment liability	14,200	21,000
Recurring | Broad Institute | Carrying Amount
Liabilities
Success payment liability	14,400	21,200
Recurring | Broad Institute | Fair Value
Liabilities
Success payment liability	14,400	21,200
Recurring | Broad Institute | Fair Value | Level 3
Liabilities
Success payment liability	$ 14,400	$ 21,200

Fair Value of Financial Instr_4

Fair Value of Financial Instruments - Schedule of Calculation of Estimated Fair Value of Success Payment Liabilities (Details) - Success Payment Liabilities	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Fair Value of Common Stock | Harvard
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability measurement input	57.30	79.69
Fair Value of Common Stock | Broad Institute
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability measurement input	57.30	79.69
Expected Volatility | Harvard
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability measurement input	0.80	0.76
Expected Volatility | Broad Institute
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability measurement input	0.80	0.76
Expected Term (years) | Minimum | Harvard
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability, term	1 month 6 days	1 month 6 days
Expected Term (years) | Minimum | Broad Institute
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability, term	1 month 6 days	1 month 6 days
Expected Term (years) | Maximum | Harvard
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability, term	7 years 3 months	7 years 5 months 26 days
Expected Term (years) | Maximum | Broad Institute
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability, term	8 years 1 month 9 days	8 years 4 months 9 days

Fair Value of Financial Instr_5

Fair Value of Financial Instruments - Schedule of Change in Fair Value of Success Payment Liabilities Based on Level 3 Inputs (Details) - Success Payment Liabilities $ in Thousands	3 Months Ended
	Mar. 31, 2022USD ($)
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning Balance	$ 42,200
Change in fair value	(13,600)
Ending Balance	28,600
Harvard
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning Balance	21,000
Change in fair value	(6,800)
Ending Balance	14,200
Broad Institute
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning Balance	21,200
Change in fair value	(6,800)
Ending Balance	$ 14,400

Fair Value of Financial Instr_6

Fair Value of Financial Instruments - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Jun. 30, 2021	Mar. 31, 2022	Mar. 31, 2021	Feb. 23, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity securities recognition amount		$ (7,685)	$ 1,039
Verve Therapeutics, Inc.
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity securities recognition amount		(7,700)	$ 1,000
Equity securities		$ 12,500
Verve Therapeutics, Inc. | Common Stock
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Number of shares purchased under equity method	546,970	546,970
Technology Milestones | Guide Therapeutics, Inc. | Maximum | Merger Agreement | Former Stockholders and Optionholders
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Potential milestone payable in form of common stock				$ 100,000
Product Milestones | Guide Therapeutics, Inc. | Maximum | Merger Agreement | Former Stockholders and Optionholders
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Potential milestone payable in form of common stock				$ 220,000

Fair Value of Financial Instr_7

Fair Value of Financial Instruments - Schedule of Change in Fair Value of Contingent Consideration Liabilities Based on Level 3 Inputs (Details) - Contingent Consideration Liabilities $ in Thousands	3 Months Ended
	Mar. 31, 2022USD ($)
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning Balance	$ 31,367
Change in fair value	(452)
Ending Balance	30,915
Technology Milestones
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning Balance	24,359
Change in fair value	172
Ending Balance	24,531
Product Milestones
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning Balance	7,008
Change in fair value	(624)
Ending Balance	$ 6,384

Fair Value of Financial Instr_8

Fair Value of Financial Instruments - Schedule of Calculation of Estimated Fair Value of Contingent Consideration Liabilities (Details) - Contingent Consideration Liabilities	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Technology Milestones | Minimum
Derivative Liability [Abstract]
Milestone liabilities projected year of achievement	2022	2022
Technology Milestones | Maximum
Derivative Liability [Abstract]
Milestone liabilities projected year of achievement	2023	2023
Product Milestones | Minimum
Derivative Liability [Abstract]
Milestone liabilities projected year of achievement	2024	2023
Product Milestones | Maximum
Derivative Liability [Abstract]
Milestone liabilities projected year of achievement	2029	2029
Discount Rate | Technology Milestones
Derivative Liability [Abstract]
Contingent consideration liability measurement input	0.0850	0.0750
Discount Rate | Product Milestones
Derivative Liability [Abstract]
Contingent consideration liability measurement input	0.0850	0.0750
Probability of Achievement | Technology Milestones | Minimum
Derivative Liability [Abstract]
Contingent consideration liability measurement input	0.10	0.10
Probability of Achievement | Technology Milestones | Maximum
Derivative Liability [Abstract]
Contingent consideration liability measurement input	0.75	0.75
Probability of Achievement | Product Milestones | Minimum
Derivative Liability [Abstract]
Contingent consideration liability measurement input	0.02	0.02
Probability of Achievement | Product Milestones | Maximum
Derivative Liability [Abstract]
Contingent consideration liability measurement input	0.15	0.15

Marketable Securities - Summary

Marketable Securities - Summary of Marketable Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Marketable securities held, Amortized Cost	$ 928,488	$ 405,703
Marketable securities held, Gross Unrealized Gains	2	32
Marketable securities held, Gross Unrealized Losses	(2,711)	(82)
Marketable securities held, Fair Value	925,779	405,653
Commercial Paper
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Amortized Cost	733,068	368,778
Available-for-sale, Gross Unrealized Gains		32
Available-for-sale, Gross Unrealized Losses	(2,101)	(67)
Available-for-sale, Fair Value	730,967	368,743
Corporate Notes
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Amortized Cost	18,249	16,758
Available-for-sale, Gross Unrealized Losses	(124)	(15)
Available-for-sale, Fair Value	18,125	16,743
U.S. Treasury Securities
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Amortized Cost	164,689
Available-for-sale, Gross Unrealized Gains	2
Available-for-sale, Gross Unrealized Losses	(486)
Available-for-sale, Fair Value	164,205
Corporate Equity Securities
Debt Securities, Available-for-sale [Line Items]
Equity securities, Amortized Cost	12,482	20,167
Equity securities, Fair Value	$ 12,482	$ 20,167

Marketable Securities - Additio

Marketable Securities - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Realized gains or losses recognized on sale or maturity of marketable securities	$ 0	$ 0
Contractual maturity dates of investments	less than one year

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Payables and Accruals [Abstract]
Employee compensation and related benefits	$ 6,771	$ 11,661
Research costs	6,545	3,133
Professional fees	3,542	3,330
Process development and manufacturing costs	2,299	3,833
Other	4,905	6,964
Total	$ 24,062	$ 28,921

Leases - Additional Information

Leases - Additional Information (Details) $ in Thousands	1 Months Ended				3 Months Ended
	Aug. 31, 2020USD ($)ft²Option	Apr. 30, 2019USD ($)Option	Oct. 31, 2018	Feb. 28, 2018USD ($)ft²	Mar. 31, 2022USD ($)	Jun. 30, 2021USD ($)	Dec. 31, 2021USD ($)	Aug. 31, 2021USD ($)	Jan. 31, 2021USD ($)	Oct. 31, 2020USD ($)
Lessee Lease Description [Line Items]
Operating lease right-of-use assets					$ 105,543		$ 102,718
Lease liability					145,393
Office and Laboratory Space
Lessee Lease Description [Line Items]
Square feet of office and laboratory space | ft²				38,203
Operating lease, commencement month and year				2018-03
Operating lease, termination month and year				2028-09		2034-02
Operating lease, option to extend		option to extend the lease for two terms of five years each, which are not reasonably certain of exercise.		a term extension option, which is not reasonably certain of exercise.
Operating lease, existence of option to extend		true		true
Operating lease, number of renewal options | Option		2
Operating lease, option to extend term		5 years
Leasehold improvements landlord allowance		$ 23,400		$ 6,100
Increase in operating lease right-of-use assets						$ 500
Increase in operating lease liability						$ 500
Operating lease term						12 years
Lessee, operating lease, lease not yet commenced anticipated undiscounted lease payments due								$ 11,100
Office and Laboratory Space | Letter of Credit
Lessee Lease Description [Line Items]
Lessee, operating lease, security deposit					9,700		$ 9,700
Office and Laboratory Space | First Phase of Lease in October 2020
Lessee Lease Description [Line Items]
Operating lease, commencement month and year		2020-10
Rent payments beginning month and year		2021-08
Operating lease right-of-use assets										$ 66,800
Lease liability										$ 68,800
Office and Laboratory Space | Second Phase of Lease in January 2021
Lessee Lease Description [Line Items]
Operating lease, commencement month and year		2021-01
Rent payments beginning month and year		2022-02
Operating lease right-of-use assets									$ 22,000
Lease liability									$ 23,000
Laboratory Space
Lessee Lease Description [Line Items]
Operating lease, commencement month and year			2019-04
Operating lease, termination month and year		2025-12
Operating lease, option to extend		The amended lease is subject to fixed-rate rent escalations and provides an option to extend the lease for two additional two-year periods through December 31, 2029, which are not reasonably certain of being exercised.
Operating lease, existence of option to extend		true
Operating lease, number of renewal options | Option		2
Operating lease, option to extend term		2 years
Operating lease right-of-use assets					14,100
Lease liability					$ 14,000
Manufacturing Facility | Alexandria Real Estate Equities, Inc.
Lessee Lease Description [Line Items]
Operating lease, existence of option to extend	true
Operating lease, number of renewal options | Option	2
Operating lease, option to extend term	5 years
Manufacturing facility, number of square feet | ft²	100,000
Operating lease term	15 years
Lessee operating lease, description					The lease has a term of 15 years following the commencement date and provides the Company the option to extend the lease term for two five-year terms. It is subject to fixed rate escalation increases and also provides up to $20.0 million for reimbursement of tenant improvements. As the lease had not commenced as of March 31, 2022, the Company has not recorded an operating lease ROU asset or lease liability for this lease in the accompanying condensed consolidated balance sheets.
Lessee, operating lease, lease not yet commenced anticipated undiscounted lease payments due	$ 69,000
Manufacturing Facility | Alexandria Real Estate Equities, Inc. | Maximum
Lessee Lease Description [Line Items]
Leasehold improvements landlord allowance	$ 20,000

Leases - Summary of Operating L

Leases - Summary of Operating Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Leases [Abstract]
Operating lease costs	$ 4,386	$ 4,558
Variable lease costs	1,136	210
Short-term lease costs	232
Sublease income	(331)	0
Total	$ 5,423	$ 4,768

Leases - Summary of Lease Term

Leases - Summary of Lease Term and Discount Rate (Details)	Mar. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Weighted-average remaining lease term (years)	10 years 7 months 6 days	11 years 1 month 6 days
Weighted-average discount rate	7.00%	7.00%

Leases - Summary of Lease Costs

Leases - Summary of Lease Costs for Amounts Included in Measurement of Lease Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Leases [Abstract]
Operating cash flows used for operating leases	$ 4,509	$ 1,685
Operating lease liabilities arising from obtaining ROU assets	$ 4,822	$ 23,366

Leases - Summary of Future Mini

Leases - Summary of Future Minimum Lease Payments of Operating Leases (Details) $ in Thousands	Mar. 31, 2022USD ($)
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
Remainder of 2022	$ 13,865
2023	19,006
2024	19,586
2025	20,066
2026	17,143
Thereafter	115,692
Undiscounted lease payments	205,358
Less: imputed interest	(59,965)
Total operating lease liabilities	$ 145,393

Guide Acquisition - Additional

Guide Acquisition - Additional Information (Details) - USD ($) $ in Thousands	Feb. 23, 2021	Mar. 31, 2021	Mar. 31, 2022	Dec. 31, 2021
Business Acquisition [Line Items]
Value of shares issued for upfront payment of acquisition		$ 120,032
Research and development expense		154,953
Contingent consideration liabilities			$ 30,915	$ 31,367
Common Stock
Business Acquisition [Line Items]
Value of shares issued for upfront payment of acquisition		$ 10
Guide Therapeutics, Inc. | Merger Agreement
Business Acquisition [Line Items]
Business Acquisition, merger agreement date	Feb. 23, 2021
Business combination upfront consideration paid in common stock	$ 120,000
Value of shares issued for upfront payment of acquisition	120,000
Research and development expense	155,000
Contingent consideration liabilities	$ 36,500
Guide Therapeutics, Inc. | Merger Agreement | Common Stock
Business Acquisition [Line Items]
Number of shares issued for upfront payment of acquisition	1,087,153
Guide Therapeutics, Inc. | Merger Agreement | Technology Milestones | Maximum | Former Stockholders and Optionholders
Business Acquisition [Line Items]
Potential milestone payable in form of common stock	$ 100,000
Guide Therapeutics, Inc. | Merger Agreement | Product Milestones | Maximum | Former Stockholders and Optionholders
Business Acquisition [Line Items]
Potential milestone payable in form of common stock	$ 220,000

Guide Acquisition - Summary of

Guide Acquisition - Summary of Transaction Price Determined and Allocated (Details) - Guide Therapeutics, Inc. - Merger Agreement $ in Thousands	Feb. 23, 2021USD ($)
Transaction price
Fair value of equity instruments issued	$ 120,032
Technology and product contingent consideration liabilities	36,513
Transaction costs	2,531
Total transaction price	159,076
Transaction price allocated
Cash acquired	3,151
Prepaid expenses and other assets	264
Property and equipment	1,835
Other liabilities assumed	(1,427)
Total transaction price	159,076
In-Process Research and Development
Transaction price allocated
Intangible assets	154,953
Assembled Workforce
Transaction price allocated
Intangible assets	$ 300

License Agreements - Harvard Li

License Agreements - Harvard License Agreement - Additional Information (Details) - Harvard	Jun. 10, 2021shares	Mar. 31, 2022USD ($)	Mar. 31, 2021USD ($)	May 31, 2021USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Success payment amount due		$ 0		$ 15,000,000
Issuance of common stock for success payment liability, Shares | shares	174,825
Milestone expense		0	$ 0
Non-royalty sublicense fees owed		500,000
Non-royalty sublicense fees accrued		33,100,000
Minimum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Success payments		$ 5,000,000
Minimum | Series A Preferred Stock
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Success Payments, valuation multiples		5
Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Additional success payment amount due				$ 90,000,000
Success payments		$ 105,000,000
Maximum | Series A Preferred Stock
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Success Payments, valuation multiples		40
Success Payments
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Agreement description		The Company is required to make success payments to Harvard during a period of time, or the Harvard Success Payment Period, which has been determined to be the later of (1) the ninth anniversary of the Harvard License Agreement or (2) the earlier of (a) the twelfth anniversary of the Harvard License Agreement and (b) the third anniversary of the first date on which a licensed product receives regulatory approval in the United States. During the Harvard Success Payment Period and beginning one year after the Company’s IPO, the Company will perform a calculation of any amounts owed to Harvard on each rolling 90-day period.

License Agreements - Harvard _2

License Agreements - Harvard License Agreement - Success Payment Liability (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Harvard
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Success payment liability	$ 14,200	$ 21,000

License Agreements - Harvard _3

License Agreements - Harvard License Agreement - Change in Fair Value of Success Payment Liability (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Change in fair value of derivative liabilities	$ (13,600)	$ 1,900
Harvard
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Change in fair value of derivative liabilities	$ (6,800)	$ 1,000

License Agreements - Broad Lice

License Agreements - Broad License Agreement - Additional Information (Details) - Broad Institute	Jun. 10, 2021shares	Mar. 31, 2022USD ($)	Mar. 31, 2021USD ($)	May 31, 2021USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Success payment amount due		$ 0		$ 15,000,000
Issuance of common stock for success payment liability, Shares | shares	174,825
Milestone expense		0	$ 0
Non-royalty sublicense fees		$ 6,100,000
Success Payments
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Agreement description		The Company is required to make success payments to Broad Institute during a period of time, or the Broad Success Payment Period, which has been determined to be the earliest of (1) the twelfth anniversary of the Broad License Agreement or (2) the third anniversary of the first date on which a licensed product receives regulatory approval in the United States. During the Broad Success Payment Period and beginning one year after the Company’s IPO, the Company will perform a calculation of any amounts owed to Broad Institute on each rolling 90-day period.
Minimum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Success payments		$ 5,000,000
Minimum | Series A Preferred Stock
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Success Payments, valuation multiples		5
Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Success payments		$ 105,000,000
Additional success payment amount due				$ 90,000,000
Maximum | Series A Preferred Stock
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Success Payments, valuation multiples		40

License Agreements - Broad Li_2

License Agreements - Broad License Agreement - Success Payment Liability (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Broad Institute
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Success payment liability	$ 14,400	$ 21,200

License Agreements - Broad Li_3

License Agreements - Broad License Agreement - Change in Fair Value of Success Payment Liability (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Change in fair value of derivative liabilities	$ (13,600)	$ 1,900
Broad Institute
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Change in fair value of derivative liabilities	$ (6,800)	$ 900

License Agreements - Editas Lic

License Agreements - Editas License Agreement - Additional Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2022USD ($)
Editas License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone expense	$ 0.1

Collaboration and License Agr_2

Collaboration and License Agreements - Additional Information (Details) - USD ($)	1 Months Ended				3 Months Ended
	Jan. 31, 2022	Dec. 31, 2021	Jul. 31, 2021	Jun. 30, 2021	Mar. 31, 2022
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Current portion of deferred revenue		$ 86,270,000			$ 115,049,000
Long-term portion of deferred revenue		$ 262,303,000			$ 225,093,000
Apellis Pharmaceuticals, Inc
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Agreement description					In June 2021, the Company entered into a research collaboration agreement, or the Apellis Agreement, with Apellis Pharmaceuticals, Inc., or Apellis, focused on the use of certain of the Company’s base editing technology to discover new treatments for complement system-driven diseases. Under the terms of the Apellis Agreement, the Company will conduct preclinical research on up to six base editing programs that target specific genes within the complement system in various organs, including the eye, liver, and brain. Apellis has an exclusive option to license any or all of the six programs, or in each case, an Opt-In Right, and will assume responsibility for subsequent development. The Company may elect to enter into a 50-50 U.S. co-development and co-commercialization agreement with Apellis with respect to one program instead of a license. The collaboration is managed on an overall basis by an alliance steering committee formed by an equal number of representatives from the Company and Apellis.
Collaboration arrangement, initial term				5 years	5 years
Upfront revenue recognized					$ 0
Collaboration agreement upfront payment received			$ 50,000,000
Collaboration agreement performance obligation revenue recognized					2,100,000
Collaboration agreement aggregate transaction price				$ 75,000,000
Upfront fee receivable upon signing contract				50,000,000
Collaboration agreement first anniversary amount receivable				25,000,000
Current portion of deferred revenue					19,400,000
Long-term portion of deferred revenue					$ 26,700,000
Apellis Pharmaceuticals, Inc | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration arrangement extension term					2 years
Apellis Pharmaceuticals, Inc | ASC 606
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Contract asset				25,000,000
Deferred revenue liability				$ 25,000,000
Pfizer
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Agreement description					In December 2021, the Company entered into a research collaboration agreement, or the Pfizer Agreement, with Pfizer Inc., or Pfizer, focused on the use of certain of the Company’s base editing technology to develop in vivo therapies for rare genetic diseases of the liver, muscle, and central nervous system. Under the terms of the Pfizer Agreement, the Company will conduct all research activities through development candidate selection for three base editing programs that target specific genes corresponding to specific diseases that are the subject of such programs. Pfizer will have exclusive rights to license each of the three programs at no additional cost, each an Opt-In Right, and will assume responsibility for subsequent development and commercialization. At the end of the Phase 1/2 clinical trials, the Company may elect to enter into a global co-development and co-commercialization agreement with Pfizer with respect to one program licensed under the collaboration for an option exercise fee equal to a percentage of the applicable development costs incurred by Pfizer, or the Participation Election. In the event the Company elects to exercise its Participation Election, upon the payment of its option exercise fee, Pfizer and the Company would share net profits as well as development and commercialization costs in a 65%/35% (Pfizer/Company) split for such program. The research collaboration is managed on an overall basis by a Joint Research Committee, or JRC, formed by an equal number of representatives from the Company and Pfizer.
Collaboration arrangement, initial term		4 years
Potential total consideration		$ 1,350,000,000
Nonrefundable upfront payment receivable		300,000,000
Collaboration agreement upfront payment received	$ 300,000,000
Collaboration agreement performance obligation revenue recognized					$ 6,300,000
Collaboration agreement aggregate transaction price		$ 300,000,000
Earn-out payment period		10 years
Current portion of deferred revenue					95,600,000
Long-term portion of deferred revenue					$ 198,100,000
Pfizer | Assigned to Company | Upon Participation Election
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Net profits as well as development and commercialization costs percentage		35.00%
Pfizer | Assigned to Pfizer | Upon Participation Election
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Net profits as well as development and commercialization costs percentage		65.00%
Pfizer | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Development regulatory and commercial milestones receivable		$ 350,000,000

Common Stock - Additional Infor

Common Stock - Additional Information (Details) - USD ($)	Jan. 16, 2021	Apr. 30, 2021	Mar. 31, 2022	Mar. 31, 2021	Jul. 31, 2021	Jul. 07, 2021
Class Of Stock [Line Items]
Common stock, voting rights			The holders of the Company’s common stock are entitled to one vote for each share of common stock.
Common Stock
Class Of Stock [Line Items]
Shares issued and sold			874,770	2,795,700
Jeffries LLC Sales Agreement
Class Of Stock [Line Items]
Gross proceeds from issuance of common stock			$ 300,000,000
Jeffries LLC Sales Agreement | Common Stock
Class Of Stock [Line Items]
Shares issued and sold					2,908,009
Public offering price per share					$ 103.16
Jeffries LLC Amended Sales Agreement
Class Of Stock [Line Items]
Gross proceeds from issuance of common stock			$ 266,500,000
Jeffries LLC Amended Sales Agreement | Common Stock
Class Of Stock [Line Items]
Shares issued and sold			2,873,956
Public offering price per share			$ 92.71
Private Placement
Class Of Stock [Line Items]
Gross proceeds from issuance of common stock	$ 260,000,000
Private Placement | Common Stock
Class Of Stock [Line Items]
Shares issued and sold	2,795,700
Public offering price per share	$ 93
Net proceeds from sale of common stock	$ 252,000,000
At-The-Market | Jeffries LLC Sales Agreement | Maximum
Class Of Stock [Line Items]
Aggregate gross proceeds of shares authorized under ATM sales agreement		$ 300,000,000
Commission rate		3.00%
At-The-Market | Jeffries LLC Amended Sales Agreement
Class Of Stock [Line Items]
Aggregate gross proceeds of shares authorized under ATM sales agreement						$ 500,000,000

Stock Option and Grant Plan - A

Stock Option and Grant Plan - Additional Information (Details) - USD ($)	1 Months Ended	3 Months Ended
	Feb. 29, 2020	Mar. 31, 2022	Mar. 31, 2021	Oct. 31, 2019	May 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense		$ 18,035,000	$ 4,648,000
Weighted-average grant date fair value per share of options granted		$ 46.09
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation expense related to unvested stock options		$ 158,400,000
Unrecognized compensation cost, cost to recognize over a weighted-average period		2 years 7 months 6 days
Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation cost, cost to recognize over a weighted-average period		3 years 6 months
Unrecognized stock-based compensation expense, expected to vest		$ 106,900,000
Restricted Stock | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period		4 years
Restricted Stock | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period		2 years
2017 Plan | Stock Options and Restricted Stock | Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Maximum number of shares for future issuance					8,078,681
2019 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Maximum number of shares for future issuance				3,700,000
Number of shares reserved for future issuance		11,226,843
Number of shares available for future issuance		2,452,727
2019 Plan | Common Stock | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Annual percentage increase in shares authorized		4.00%
2019 Plan | Including 2017 Plan Shares | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Maximum number of shares for future issuance				5,639,818
2019 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares available for future issuance		1,706,282
Number of shares issued		28,990	0
Stock-based compensation expense		$ 300,000	$ 0
Common stock, shares description		In February 2020, the Company’s board of directors adopted the Beam Therapeutics Inc. 2019 Employee Stock Purchase Plan, or ESPP, which was approved by the Company’s stockholders. Pursuant to the ESPP, certain employees of the Company, excluding consultants and non-employee directors, are eligible to purchase common stock of the Company at a reduced rate during offering periods. The ESPP permits participants to purchase common stock using funds contributed through payroll deductions, subject to a calendar year limit of $25,000 and at a purchase price of 85% of the lower of the fair market value of the Company’s common stock on the first trading day of the offering period or on the applicable purchase date, which will be the final trading day of the applicable purchase period. The first offering period commenced on October 1, 2021.
Maximum amount allowed to purchase common stock using payroll deduction	$ 25,000
Percentage of common stock purchase price lower of the fair market value	85.00%
Common stock, offering period, start date	Oct. 1, 2021

Stock Option and Grant Plan - S

Stock Option and Grant Plan - Summary of Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 18,035	$ 4,648
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	11,294	3,155
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 6,741	$ 1,493

Stock Option and Grant Plan -_2

Stock Option and Grant Plan - Summary of Option Activity Under Equity Award Plans (Details)	3 Months Ended
	Mar. 31, 2022$ / sharesshares
Number of options
Outstanding at December 31, 2021 | shares	6,034,192
Granted | shares	1,427,500
Exercised | shares	(176,652)
Forfeitures | shares	(20,637)
Outstanding at March 31, 2022 | shares	7,264,403
Exercisable as of March 31, 2022 | shares	2,602,709
Weighted average exercise price
Outstanding at December 31, 2021 | $ / shares	$ 32.40
Granted | $ / shares	69.13
Exercised | $ / shares	4.64
Forfeitures | $ / shares	36.41
Outstanding at March 31, 2022 | $ / shares	40.28
Exercisable as of March 31, 2022 | $ / shares	$ 15.83

Stock Option and Grant Plan -_3

Stock Option and Grant Plan - Summary of Restricted Stock Activity (Details) - Restricted Stock	3 Months Ended
	Mar. 31, 2022$ / sharesshares
Shares
Unvested as of December 31, 2021 | shares	1,126,206
Issued | shares	711,025
Vested | shares	(283,186)
Forfeited | shares	(11,519)
Unvested as of March 31, 2022 | shares	1,542,526
Weighted-average grant date fair value
Unvested as of December 31, 2021 | $ / shares	$ 74.32
Issued | $ / shares	57.30
Vested | $ / shares	38.69
Cancelled | $ / shares	86.15
Unvested as of March 31, 2022 | $ / shares	$ 72.93

Net Loss per Share - Schedule o

Net Loss per Share - Schedule of Potential Common Shares Excluded from Computation of Diluted Net Loss per Share (Details) - shares	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive shares excluded from computation of diluted net loss per share	8,806,929	7,496,240
Unvested Restricted Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive shares excluded from computation of diluted net loss per share	1,542,526	1,388,114
Outstanding Options to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive shares excluded from computation of diluted net loss per share	7,264,403	6,108,126

Net Loss per Share - Summary of

Net Loss per Share - Summary of Computation of Basic and Diluted Net Loss per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Numerator:
Net loss	$ (69,214)	$ (201,560)
Denominator:
Weighted average common shares outstanding, basic	68,703,864	60,210,120
Weighted average common shares outstanding, diluted	68,703,864	60,210,120
Net loss per common share , basic	$ (1.01)	$ (3.35)
Net loss per common share , diluted	$ (1.01)	$ (3.35)

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details)	1 Months Ended		3 Months Ended		6 Months Ended
	Oct. 31, 2021USD ($)ft²	Jun. 30, 2021shares	Mar. 31, 2022USD ($)Foundershares	Mar. 31, 2021USD ($)	Mar. 31, 2021USD ($)
Related Party Transaction [Line Items]
Number of founder shareholders | Founder			3
Sublease income			$ 331,000	$ 0
Office and Laboratory Space
Related Party Transaction [Line Items]
Operating lease term		12 years
Founder Shareholders | Scientific Consulting and Other Expenses
Related Party Transaction [Line Items]
Payments received from (made to) related parties			(100,000)	(100,000)
Verve Therapeutics, Inc.
Related Party Transaction [Line Items]
Equity securities			12,500,000
Other expense			7,700,000
Other income				1,000,000
Verve Therapeutics, Inc. | Office and Laboratory Space
Related Party Transaction [Line Items]
Sublease area of rented space | ft²	12,000
Operating lease term	1 year
Sublease, commencement month and year	2021-12
Rental payment over term of sublease	$ 1,400,000
Sublease income			$ 300,000
Verve Therapeutics, Inc. | Common Stock
Related Party Transaction [Line Items]
Number of shares purchased under equity method | shares		546,970	546,970
Verve Therapeutics, Inc. | Research and Development Expense
Related Party Transaction [Line Items]
Purchases from related party			$ 0	$ 200,000
Reimbursed Costs | Prime Agreement | Interest and Other Income (Expense), Net | Prime Medicine Inc | Monthly Fee
Related Party Transaction [Line Items]
Income from related party					$ 30,000