Significant Agreements - Additional Information (Details)		1 Months Ended			6 Months Ended	12 Months Ended
	Oct. 24, 2023	Dec. 31, 2021 USD ($)	May 31, 2021 USD ($) Agreements	Jan. 31, 2020 USD ($) shares	Jun. 30, 2024 USD ($)	Dec. 31, 2023 USD ($) shares	Dec. 31, 2022 USD ($)	Dec. 31, 2020 USD ($)
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Shares issued | shares						349,321
National Institutes of Health
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaboration, option and license agreement, description					Under the NIH Agreements, commencing in January 2023 and subsequently on January 1 of each calendar year thereafter, the Company is also required to make minimum annual royalty payments of $0.2 million, which shall be credited against any earned royalties due based on a low single-digit percentage of net sales made in a respective year. In addition, benchmark royalties following the completion of certain regulatory-and clinical-related benchmarks are due to the NIH, with the minimum cumulative royalty due for a product reaching FDA approval or foreign-equivalent approval totaling $5.7 million for the autologous patent license agreement and $1.7 million for the allogeneic patent license agreement. Additional benchmark royalties would be payable for a subsequent indication under each NIH Agreement. If the Company enters into a sublicensing agreement, it will be required to pay the NIH a sublicense royalty payment as a percentage of the fair market value of any consideration received for each sublicense granted. The sublicensing percentage starts at a high teens to low twenties percentage if clinical trials for the product have not yet begun and decreases to a mid-single-digit percentage if the product has received FDA approval or foreign-equivalent approval.
Intellia Therapeutics, Inc.
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaboration, option and license agreement, description					Under the Intellia Agreement, Intellia owns rights, title and interests in and to any intellectual property developed in the course of performance under the Intellia Agreement that is not specifically directed to the CRISPR Product. The Company granted to Intellia certain non-exclusive, royalty-free, fully paid-up, worldwide licenses under the Company’s intellectual property solely to perform the activities designated to Intellia under the collaboration, and to research, develop or otherwise exploit any human therapeutic product that is developed or commercialized by Intellia, utilizes or incorporates Intellia intellectual property and that is not the CRISPR Product or any product directed to CD19 or any other B-cell antigen.In addition, the Company granted Intellia an exclusive option (the “Intellia Option”) to enter into a co-development and co-commercialization agreement with the Company for the CRISPR Product, (the “Co-Co Agreement”) for a fee payable to the Company. If Intellia exercises the Intellia Option, the Company and Intellia would share equally the regulatory and clinical development expenses associated with obtaining approval of the CRISPR Product in the U.S. and would also share equally all net profits and losses from commercialization of the CRISPR Product in the U.S. If Intellia exercises the Intellia Option, no milestone payments will be due and payable from that time forward and the Company will only pay royalties on sales outside of the U.S. In addition, upon exercise of the Intellia Option, following regulatory approval of the CRISPR Product, Intellia will have exclusive commercialization rights for the CRISPR Product for U.S. administration, subject to the Company’s rights to co-promote the CRISPR Product in the U.S., and the Company will retain the sole and exclusive rights to research, develop, or otherwise exploit the CRISPR Product for rest-of-world administration and shall have sole decision-making authority in relation thereto, subject to the parties’ obligations to cooperate regarding certain development, regulatory and commercialization strategies.
Gilead Sciences, Inc.
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaboration, option and license agreement, description					Pursuant to the Gilead Agreement, the Company also granted Gilead, on a research program-by-program basis, an exclusive option, exercisable at any time during the Option Period for such program, to obtain an exclusive license under such program’s intellectual property to develop, manufacture, and commercialize optioned products belonging to such program for a specified fee and on the terms and conditions set out in the Gilead Agreement. For purposes of the foregoing, an Option Period meant, on a program-by-program basis, the period commencing on the date of execution of the Gilead Agreement and ending upon the earlier of (i) the expiration of the review period for such program, and (ii) the ten-year anniversary of the date of execution of the Gilead Agreement.Unless terminated earlier, the Gilead Agreement was to expire, with respect to each program, (i) upon such program becoming a terminated program, or (ii) on an optioned product-by-optioned product and country-by-country basis, upon the expiration of the royalty term with respect to such optioned product in such country with respect to such program. Gilead had the right to terminate the Gilead Agreement at will, in its sole discretion, in its entirety or on a program-by-program or optioned program-by-optioned program basis at any time upon ninety days’ prior written notice to the Company. In addition, either party was able to terminate the Gilead Agreement for uncured material breach by the other party, or upon the occurrence of insolvency-related events of the other party.The royalty term under the Gilead Agreement continued on an optioned product-by-optioned product and country-by-country basis until the latest of: (i) the date on which there is no valid claim of a program patent; (ii) the expiration of any regulatory exclusivity with respect to such optioned product in the relevant country; and (iii) the ten-year anniversary of the date of the first commercial sale of such optioned product in such country.
Kite Pharma, Inc.
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaboration, option and license agreement, description					Pursuant to the Kite Agreement, the Company is also obligated to pay mid-teen-and mid-single-digit percentages of annual maintenance fees, minimum annual royalties and patent prosecution costs payable under the UCSF License Agreement during the co-exclusive term and non-exclusive term, respectively. The Company was also obligated to pay a $6.3 million sublicensing fee under the UCSF License Agreement, which the Company agreed to offset with future milestone payments payable by Gilead under the Gilead Agreement.Unless terminated earlier, the Kite Agreement will expire upon the expiration of all licensed patents and Kite improvement patents therein. The Company has the right to terminate the Kite Agreement at will, in the Company’s sole discretion, in its entirety upon 90 days’ written notice to Kite. In addition, either party may terminate the Kite Agreement for uncured material breach by the other party, or upon the occurrence of insolvency-related events of the other party.The acquisition of the co-exclusive license under the Kite Agreement, including patent rights and know-how, was accounted for as an asset acquisition. As the acquired technology did not have an alternative use for accounting purposes, the license consideration of $3.5 million and the sublicensing fee of $6.3 million was recorded as a research and development expense in the statements of operations and comprehensive loss for the year ended December 31, 2020.
Patent License Agreements | National Institutes of Health
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Minimum annual royalty payments			$ 200,000
Number of agreements | Agreements			2
Acquired licenses, amount paid			$ 3,300,000
Royalties payable					$ 0	$ 0
Patent License Agreements | Research and Development Expense | National Institutes of Health
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Acquired licenses, amount paid							$ 3,300,000
Patent License Agreements | Autologous Patent License Agreement | National Institutes of Health
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Cumulative royalty due			5,700,000
Patent License Agreements | Allogeneic Patent License Agreement | National Institutes of Health
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Cumulative royalty due			$ 1,700,000
License and Collaboration Agreement | Intellia Therapeutics, Inc.
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Milestone payments					0	0
License and Collaboration Agreement | Intellia Therapeutics, Inc. | Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Milestone payments		$ 64,500,000
License and Collaboration Agreement | Intellia Therapeutics, Inc. | Series B Preferred Stock
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Temporary equity shares issued, fair value		$ 7,000,000
Collaboration, Option and License Agreement | Gilead Sciences, Inc.
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Proceeds from one-time non-refundable and non-creditable payment				$ 17,500,000
Estimated transaction price				17,500,000
Number of days of notice period for terminating agreement	90 days
Kite License Agreement | Kite Pharma, Inc.
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Sublicensing fee				6,300,000
License consideration								$ 3,500,000
Sublicense fee to be offset against future milestone payable, not agreed					3,800,000
Sublicense fee payable related to qualified financing						2,500,000
Kite License Agreement | Kite Pharma, Inc. | Accrued License Expense, Related Party
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Sublicensing fee					$ 6,300,000	$ 6,300,000
Kite License Agreement | Kite Pharma, Inc. | Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Milestone payments				$ 10,800,000
Kite License Agreement | Kite Pharma, Inc. | Series A-2 Redeemable Convertible Preferred Stock
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Shares issued | shares				4,042,066
Kite License Agreement | Research and Development Expense | Kite Pharma, Inc.
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Sublicensing fee								$ 6,300,000
Stock Purchase Agreement | Gilead Sciences, Inc. | Series A-2 Redeemable Convertible Preferred Stock
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Shares issued | shares				6,890,744