Share-based compensation - Summary of Share-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2026	Mar. 31, 2025
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	$ 78	$ 137
Research and Development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	0	15
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	$ 78	$ 122

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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