Stockholders' equity - June 2024 registered direct offering and private placement (Details) $ / shares in Units, $ in Millions	1 Months Ended
Jun. 30, 2024 USD ($) security $ / shares shares	Dec. 31, 2024 shares
Series A warrant
Shares of common stock issuable for Issued and outstanding warrants \| shares		846,105
Threshold period following the public announcement of receiving positive phase 1 multiple ascending dose data for expiry of warrants	60 days
June 2024 Offering
Number of Securities \| security	2
Consideration received \| $	$ 20.0
Shares issued (in shares) \| shares	3,307,889
Offering shares (Per share) \| $ / shares	$ 3.93
Percentage of placement agent fee	7.00%
Non-accountable expenses and clearing costs \| $	$ 0.1
Percentage of common stock sold	5.00%
June 2024 Offering \| Pre-Funded Warrants
Offering shares (Per share) \| $ / shares	$ 3.929
Shares of common stock issuable for Issued and outstanding warrants \| shares	1,781,171
Exercise Price \| $ / shares	$ 0.001
Maximum percentage of outstanding common stock	9.99%
Number of days written notice	61 days
June 2024 Offering \| Series A warrant
Shares of common stock issuable for Issued and outstanding warrants \| shares	5,089,060
Expired terms	12 months
June 2024 Offering \| Series B warrants
Shares of common stock issuable for Issued and outstanding warrants \| shares	7,633,591
Expired terms	5 years
Threshold period following the public announcement of receiving positive phase 1 multiple ascending dose data for expiry of warrants	6 months
June 2024 Offering \| PIPE common warrants
Shares issued (in shares) \| shares	763,359
Exercise Price \| $ / shares	$ 3.93
Maximum percentage of outstanding common stock	4.99%
June 2024 Offering \| Placement agent warrants
Shares of common stock issuable for Issued and outstanding warrants \| shares	127,227
Exercise Price \| $ / shares	$ 4.9125
Premium of offering price per share (as a percent)	125.00%
Weighted average fair value of warrants \| $ / shares	$ 2.73
Terminate of common stock	2 years
Non-cash issuance cost \| $	$ 0.3
June 2024 Offering \| Placement Agent Contingent Warrants
Shares of common stock issuable for Issued and outstanding warrants \| shares	318,067
Exercise Price \| $ / shares	$ 4.9125
Weighted average fair value of warrants \| $ / shares	$ 3.43
June 2024 Offering \| Dong-A
Consideration received \| $	$ 10.0

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The threshold period following the public announcement of the Company receiving positive Phase 1 multiple ascending dose ("MAD") data for expiry of warrants.

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The weighted average fair value per share of warrants.

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The cash inflow from the issuance of common stock, preferred stock, treasury stock, stock options, and other types of equity.

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Per share or per unit amount of equity securities issued.

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Fair value portion of warrants not settleable in cash classified as equity.

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