Consolidated statements of operations and comprehensive loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Income Statement [Abstract]
Collaboration revenue - related party	$ 2,370	$ 2,380
Operating expenses:
Research and development	62,966	31,799
General and administrative	17,168	10,695
Total operating expenses	80,134	42,494
Loss from operations	(77,764)	(40,114)
Other income (expense):
Change in fair value of preferred stock tranche right liabilities	2,859	15,527
Interest income	12,123	4,165
Other expense, net	(24)	(115)
Total other income, net	14,958	19,577
Net loss	(62,806)	(20,537)
Redeemable convertible preferred stock cumulative dividends	(13,589)	(17,718)
Net loss attributable to common stockholders	$ (76,395)	$ (38,255)
Net loss per share attributable to common stockholders, basic	$ (5.58)	$ (12.95)
Net loss per share attributable to common stockholders, diluted	$ (5.58)	$ (12.95)
Weighted-average common shares outstanding, basic	13,682,326	2,953,756
Weighted-average common shares outstanding, diluted	13,682,326	2,953,756
Comprehensive loss:
Net loss	$ (62,806)	$ (20,537)
Unrealized gain (loss) on investments, net of tax	(46)	21
Total other comprehensive income (loss)	(46)	21
Comprehensive loss	$ (62,852)	$ (20,516)