Income Taxes - Deferred tax assets and liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Deferred tax assets:
Net operating losses	$ 30,454	$ 25,786
Capitalized research costs	5,596	4,456
Research and development credit	1,604	1,604
Accrued compensation	482	392
Stock-based compensation	11	269
Operating lease liabilities	30	14
State taxes	130
Other	297	114
Total deferred tax assets	38,604	32,635
Less: Valuation allowance	(36,857)	(32,100)
Total deferred tax assets, net of valuation allowance	1,747	535
Deferred tax liabilities:
Right-of-use assets	(29)	(14)
Intangible assets	(2,080)
Unrecognized tax benefit	(521)	(521)
Total deferred tax liabilities	2,630	535
Net deferred tax liabilities	$ (883)	$ 0