License, Collaboration, and Success Payment Agreements - Narrative (Details)	3 Months Ended
	Mar. 31, 2024 USD ($)	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)	Oct. 31, 2020 USD ($) $ / shares	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($) $ / shares
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Research and development expense	$ 43,174,000	$ 44,630,000
Series A Convertible Preferred Stock
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Convertible preferred stock, par value (in dollars per share) | $ / shares				$ 1.83		$ 1.83
Fred Hutch | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Annual license maintenance payments						$ 50,000
Aggregate research payments due						$ 12,000,000
Term of collaborative arrangement for research						6 years
Research and development expense	100,000	300,000
Aggregate success payments	0
Term of success payment agreement						9 years
Trigger period from IPO date						1 year
Trigger period thereafter						2 years
Fair value of potential success payments due	1,100,000		$ 700,000
Success payment expense (reversal)	400,000	(1,100,000)
Fred Hutch | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement | Minimum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Multiple of initial equity value at issuance						10
Aggregate success payments						$ 10,000,000
Per share common stock price required for payment (in dollars per share) | $ / shares						$ 18.29
Fred Hutch | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement | Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Multiple of initial equity value at issuance						50
Aggregate success payments						$ 200,000,000
Per share common stock price required for payment (in dollars per share) | $ / shares						$ 91.44
Stanford | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Annual license maintenance payments					$ 50,000
Aggregate research payments due				$ 12,000,000
Term of collaborative arrangement for research				4 years
Research and development expense	800,000	800,000
Aggregate success payments	0
Term of success payment agreement				9 years
Trigger period from IPO date				1 year
Trigger period thereafter				2 years
Fair value of potential success payments due	1,700,000		1,100,000
Success payment expense (reversal)	500,000	$ (600,000)
Success payment liability	$ 1,500,000		$ 900,000
Stanford | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement | License
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential milestone payments due					2,500,000
Stanford | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement | Minimum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Multiple of initial equity value at issuance				10
Aggregate success payments				$ 10,000,000
Per share common stock price required for payment (in dollars per share) | $ / shares				$ 18.29
Stanford | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement | Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Multiple of initial equity value at issuance				50
Aggregate success payments				$ 200,000,000
Per share common stock price required for payment (in dollars per share) | $ / shares				$ 91.44
Stanford | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement | Maximum | License
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential milestone payments due					$ 3,700,000