Commitments and Contingencies - Narrative (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2026 USD ($) ft²	Mar. 31, 2025 USD ($)	Dec. 31, 2025 USD ($)	Dec. 22, 2025 USD ($) ft² leaseCompenent	Sep. 01, 2023 USD ($)
Lessee, Lease, Description [Line Items]
Operating lease right-of-use assets	$ 363		$ 397
Lease liability	2,122
General and administrative	4,205	$ 3,812
Research and development	10,160	$ 10,146
Operating lease liabilities, current portion	384		286
Operating lease liabilities, net of current portion	$ 1,738		1,688
Office And Laboratory Space In Cambridge
Lessee, Lease, Description [Line Items]
Area of lease (approximately) | ft²	30,000
Accelerated termination period				30 days
Office And Laboratory Space In Watertown, Massachusetts
Lessee, Lease, Description [Line Items]
Area of lease (approximately) | ft²				44,000
Commencement period following execution				180 days
Number of lease components | leaseCompenent				2
Operating lease right-of-use assets				$ 0
Lease liability				1,100
Gain on termination of lease			300
General and administrative			100
Research and development			200
Lease modification fee				$ 2,100
Initial rent-free period				18 months
Renewal term				5 years
Office And Laboratory Space In Boulder
Lessee, Lease, Description [Line Items]
Area of lease (approximately) | ft²	5,300
Operating lease right-of-use assets	$ 400				$ 1,400
Term of lease					5 years
Incremental borrowing rate used for lease					7.12%
Operating lease liabilities, current portion	300				$ 200
Operating lease liabilities, net of current portion	$ 500				$ 1,200
Impairment of right-of-use asset			$ 500