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Commitments and Contingencies - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Commitments and Contingencies
Loss on abandonment of operating lease right-of-use asset	$ 927	$ 0	$ 927	$ 0
Loss on finance lease right-of-use assets	1,000		1,000
Financing liability	349		349
Loss contingency, estimate of possible loss	1,900		1,900
Accounts Payable
Commitments and Contingencies
Loss contingency, estimate of possible loss	1,400		1,400
Accrued Expenses
Commitments and Contingencies
Loss contingency, estimate of possible loss	500		500
Penn | Penn License Agreement
Commitments and Contingencies
Annual payments to be made			25
Additional milestone payments for first CAR-M product			1,700
Penn | Penn License Agreement | Maximum
Commitments and Contingencies
Milestone payments	10,900		10,900
Additional milestone payments			30,000
Laboratory Equipment
Commitments and Contingencies
Financing liability	800		800
Loss on failed sale and leaseback	$ 1,600		$ 1,600

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