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Funding received from the Company's collaboration agreement with Janssen Pharmaceuticals for the research, development and commercialization of gene therapies for the treatment of inherited retinal diseases..

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Milestone funding received for the regulatory approval of a Janssen-selected manufacturing facility in each of the United States and European Union for commercial manufacture of the RPGR Product in connection with the Company's asset purchase agreement with Janssen Pharmaceuticals.

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Principal Business Activity (Details) - USD ($) $ in Thousands			1 Months Ended			3 Months Ended	12 Months Ended
	Nov. 07, 2025	Mar. 09, 2025	Dec. 31, 2023	Dec. 31, 2021	Mar. 31, 2019	Mar. 31, 2026	Dec. 31, 2025	Dec. 31, 2024
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Accumulated deficit							$ 816,223	$ 702,022
Cash flows from operations							46,359	104,495
Cash, cash equivalents			$ 130,649				68,193	105,668
Janssen Pharmaceuticals Inc \| Collaboration Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Non-refundable upfront cash funding					$ 100,000
Milestone funding				$ 30,000
Janssen Pharmaceuticals Inc \| Asset Purchase Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Non-refundable upfront cash funding			65,000
Milestone funding								$ 60,000
Milestone funding for extension of RPGR product clinical trials			50,000
Milestone funding for development of drug substances			10,000
Milestone funding for development of drug products			5,000
Milestone funding for sale of drug products in the US			175,000
Milestone funding for sale of drug products in the UK, France, Germany, Spain and Italy			75,000
Milestone funding for transfer of manufacturing technology			25,000
Milestone funding upon regulatory approval			10,000
Hologen Limited \| Collaboration Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Class A shares of Hologen received in transaction		500,000
Hologen Limited \| Hologen Strategic Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Milestone funding upfront payment received		$ 200,000
Additional funding payment received							50,000
Funding receivables							$ 5,000
Class A share ownership percentage of Hologen Neuro		30.00%
Class B share ownership percentage of Hologen Neuro		70.00%
Milestone funding to provide additional capital		$ 230,000
Percentage approval of directors		70.00%
Hologen Limited \| Manufacturing Framework Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Percentage approval of directors		70.00%
Purchase option after twelve months, percentage of Company's outstanding common shares		40.00%
Vesting period, irrevocable option to purchase shares of MeiraGTx Manufacturing		3 years
Eli Lilly \| Eli Lilly Collaboration Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Initial funding	$ 75,000
Contingent funding available	400,000
Milestone funding contingent on development and regulatory approval	$ 135,000
Maximum \| Janssen Pharmaceuticals Inc \| Asset Purchase Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Contingent funding available			$ 350,000
Maximum \| Hologen Limited \| Hologen Strategic Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Milestone funding to provide additional capital		$ 230,000
Subsequent Event \| Hologen Limited \| Hologen Strategic Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Additional funding payment received						$ 55,000
Subsequent Event \| Eli Lilly \| Eli Lilly Collaboration Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Additional funding payment received						$ 55,000