Segment Disclosures (Details) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Dec. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2025 USD ($) segment	Dec. 31, 2024 USD ($)	Jun. 30, 2025 USD ($)
Segment Disclosures
Number of reportable segment | segment			1
Research and development:
Total research and development	$ 14,348	$ 12,627	$ 27,497	$ 25,381
General and administrative:
Total general and administrative	9,873	4,453	16,541	8,640
Operating loss	(24,221)	(17,080)	(44,038)	(34,021)
Total non-operating income, net	1,447	1,350	3,114	2,913
Net loss	(22,774)	(15,730)	(40,924)	(31,108)	$ (74,400)
Single reportable segment
Research and development:
Total research and development	14,348	12,627	27,497	25,381
General and administrative:
Compensation and benefits	4,917	2,602	8,267	4,854
Other general and administrative segment expenses	4,956	1,851	8,274	3,786
Total general and administrative	9,873	4,453	16,541	8,640
Operating loss	(24,221)	(17,080)	(44,038)	(34,021)
Total non-operating income, net	1,447	1,350	3,114	2,913
Net loss	(22,774)	(15,730)	(40,924)	(31,108)
Single reportable segment | Ersodetug
Research and development:
Total research and development	5,647	7,260	11,257	14,476
Single reportable segment | Compensation and benefits
Research and development:
Total research and development	6,991	4,491	12,579	8,788
Single reportable segment | Other research and development segment expenses
Research and development:
Total research and development	$ 1,710	$ 876	$ 3,661	$ 2,117