Nature of the business (Details) $ in Thousands	3 Months Ended						9 Months Ended
Nature of the business (Details) $ in Thousands	Dec. 31, 2025 USD ($) product	Sep. 30, 2025 USD ($)	Jun. 30, 2025 USD ($)	Dec. 31, 2024 USD ($)	Sep. 30, 2024 USD ($)	Jun. 30, 2024 USD ($)	Dec. 31, 2025 USD ($) product	Dec. 31, 2024 USD ($)	Mar. 31, 2025 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of product candidates under development \| product	3						3
Net loss	$ 70,930	$ 83,100	$ 86,693	$ 66,340	$ 53,055	$ 53,772	$ 240,723	$ 173,167
Accumulated deficit	$ 1,189,302						$ 1,189,302		$ 948,579

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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+ Details

- Definition

Amount of accumulated undistributed earnings (deficit).

+ References + Details

Replimune Group, Inc. 10-Q