Stock-Based Compensation - Schedule of Activity for Stock Options (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2025	Dec. 31, 2024
2019 Plan \| Service Based Stock Options
Number of Options and Unvested Shares
Number of Options and Unvested Shares, beginning balance (in shares)	7,408,005
Options granted (in shares)	3,217,256
Options exercised (in shares)	(184,060)
Options cancelled / forfeited (in shares)	(138,439)
Number of Options and Unvested Shares, ending balance (in shares)	10,302,762	7,408,005
Options vested and expected to vest (in shares)	10,302,762
Options exercisable (in shares)	3,887,846
Weighted Average Exercise Price
Weighted Average Exercise Price, beginning balance (in USD per share)	$ 3.16
Options granted (in USD per share)	1.58
Options exercised (in USD per share)	1
Options cancelled / forfeited (in USD per share)	1.04
Weighted Average Exercise Price, ending balance (in USD per share)	2.73	$ 3.16
Options vested and expected to vest (in USD per share)	2.73
Options exercisable (in USD per share)	$ 4.92
Weighted average remaining contractual life (years)
Weighted average remaining contractual life (years)	8 years 5 months 15 days	8 years 4 months 13 days
Options vested and expected to vest as of June 30, 2025	8 years 5 months 15 days
Options exercisable as of June 30, 2025	7 years 8 months 19 days
Aggregate intrinsic value
Aggregate intrinsic value	$ 2,807	$ 4,285
Options exercised	120
Options vested and expected to vest as of June 30, 2025	2,807
Options exercisable as of June 30, 2025	$ 1,156
2019 Novosteo Plan \| Employee Stock Option
Number of Options and Unvested Shares
Number of Options and Unvested Shares, beginning balance (in shares)	163,839
Options granted (in shares)	0
Options exercised (in shares)	0
Number of Options and Unvested Shares, ending balance (in shares)	163,839	163,839
Options vested and expected to vest (in shares)	163,839
Options exercisable (in shares)	105,632
Weighted Average Exercise Price
Weighted Average Exercise Price, beginning balance (in USD per share)	$ 0.55
Options granted (in USD per share)	0
Options exercised (in USD per share)	0
Options cancelled / forfeited (in USD per share)	0
Weighted Average Exercise Price, ending balance (in USD per share)	0.55	$ 0.55
Options vested and expected to vest (in USD per share)	0.55
Options exercisable (in USD per share)	$ 0.55
Weighted average remaining contractual life (years)
Weighted average remaining contractual life (years)	6 years 8 months 23 days	7 years 2 months 23 days
Options vested and expected to vest as of June 30, 2025	6 years 8 months 23 days
Options exercisable as of June 30, 2025	6 years 8 months 23 days
Aggregate intrinsic value
Aggregate intrinsic value	$ 180	$ 216
Options vested and expected to vest as of June 30, 2025	180
Options exercisable as of June 30, 2025	$ 116
2022 Inducement Plan \| Employee Stock Option
Number of Options and Unvested Shares
Number of Options and Unvested Shares, beginning balance (in shares)	2,333,306
Options granted (in shares)	0
Options exercised (in shares)	0
Options cancelled / forfeited (in shares)	0
Number of Options and Unvested Shares, ending balance (in shares)	2,333,306	2,333,306
Options vested and expected to vest (in shares)	2,333,306
Options exercisable (in shares)	1,798,589
Weighted Average Exercise Price
Weighted Average Exercise Price, beginning balance (in USD per share)	$ 2.98
Options granted (in USD per share)	0
Options exercised (in USD per share)	0
Options cancelled / forfeited (in USD per share)	0
Weighted Average Exercise Price, ending balance (in USD per share)	2.98	$ 2.98
Options vested and expected to vest (in USD per share)	2.98
Options exercisable (in USD per share)	$ 2.98
Weighted average remaining contractual life (years)
Weighted average remaining contractual life (years)	6 years 10 months 24 days	7 years 4 months 20 days
Options vested and expected to vest as of June 30, 2025	6 years 10 months 24 days
Options exercisable as of June 30, 2025	6 years 10 months 24 days
Aggregate intrinsic value
Aggregate intrinsic value	$ 0	$ 0
Options vested and expected to vest as of June 30, 2025	0
Options exercisable as of June 30, 2025	$ 0

Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Aggregate Intrinsic Value

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Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Weighted Average Remaining Contractual Life

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

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Gross number of share options (or share units) granted during the period.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Weighted-average exercise price, at which grantee can acquire shares reserved for issuance, for fully vested and expected to vest exercisable or convertible options. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Amount by which current fair value of underlying stock exceeds exercise price of fully vested and expected to vest options outstanding. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Number of fully vested and expected to vest options outstanding that can be converted into shares under option plan. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Weighted-average exercise price, at which grantee can acquire shares reserved for issuance, for fully vested and expected to vest options outstanding. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average remaining contractual term for fully vested and expected to vest exercisable or convertible options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Number of share options (or share units) exercised during the current period.

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