Fair Value Measurements and Fair Value of Financial Instruments - Schedule of Financial Instruments Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022
Liabilities:
Cash and cash equivalents	$ 104,058	$ 58,338	$ 82,085
U.S. government agency bonds
Liabilities:
Cash and cash equivalents		3,976
Commercial paper
Liabilities:
Cash and cash equivalents		26,669
Fair Value, Recurring
Assets:
Assets fair value	396,707	317,036
Liabilities:
Liabilities fair value	1,256	1,651
Fair Value, Recurring | U.S. Treasury bills
Assets:
Assets fair value	295,659	91,966
Fair Value, Recurring | U.S. government agency bonds
Assets:
Assets fair value	55,476	63,659
Fair Value, Recurring | Money market funds
Assets:
Assets fair value	19,556	27,693
Fair Value, Recurring | Commercial paper
Assets:
Assets fair value	20,546	96,899
Fair Value, Recurring | Corporate debt securities
Assets:
Assets fair value	5,470	36,819
Fair Value, Recurring | MSKCC success payments liability
Liabilities:
Liabilities fair value	1,256	1,651
Fair Value, Recurring | Level 1
Assets:
Assets fair value	315,215	119,659
Liabilities:
Liabilities fair value	0	0
Fair Value, Recurring | Level 1 | U.S. Treasury bills
Assets:
Assets fair value	295,659	91,966
Fair Value, Recurring | Level 1 | U.S. government agency bonds
Assets:
Assets fair value	0	0
Fair Value, Recurring | Level 1 | Money market funds
Assets:
Assets fair value	19,556	27,693
Fair Value, Recurring | Level 1 | Commercial paper
Assets:
Assets fair value	0	0
Fair Value, Recurring | Level 1 | Corporate debt securities
Assets:
Assets fair value	0	0
Fair Value, Recurring | Level 1 | MSKCC success payments liability
Liabilities:
Liabilities fair value	0	0
Fair Value, Recurring | Level 2
Assets:
Assets fair value	81,492	197,377
Liabilities:
Liabilities fair value	0	0
Fair Value, Recurring | Level 2 | U.S. Treasury bills
Assets:
Assets fair value	0	0
Fair Value, Recurring | Level 2 | U.S. government agency bonds
Assets:
Assets fair value	55,476	63,659
Fair Value, Recurring | Level 2 | Money market funds
Assets:
Assets fair value	0	0
Fair Value, Recurring | Level 2 | Commercial paper
Assets:
Assets fair value	20,546	96,899
Fair Value, Recurring | Level 2 | Corporate debt securities
Assets:
Assets fair value	5,470	36,819
Fair Value, Recurring | Level 2 | MSKCC success payments liability
Liabilities:
Liabilities fair value	0	0
Fair Value, Recurring | Level 3
Assets:
Assets fair value	0	0
Liabilities:
Liabilities fair value	1,256	1,651
Fair Value, Recurring | Level 3 | U.S. Treasury bills
Assets:
Assets fair value	0	0
Fair Value, Recurring | Level 3 | U.S. government agency bonds
Assets:
Assets fair value	0	0
Fair Value, Recurring | Level 3 | Money market funds
Assets:
Assets fair value	0	0
Fair Value, Recurring | Level 3 | Commercial paper
Assets:
Assets fair value	0	0
Fair Value, Recurring | Level 3 | Corporate debt securities
Assets:
Assets fair value	0	0
Fair Value, Recurring | Level 3 | MSKCC success payments liability
Liabilities:
Liabilities fair value	$ 1,256	$ 1,651