Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2026	Dec. 31, 2025
Current assets:
Cash and cash equivalents	$ 89,983	$ 91,145
Marketable securities	592,833	700,007
Prepaid expenses and other current assets	14,589	12,746
Total current assets	697,405	803,898
Property and equipment, net	890	1,159
Right-of-use assets, operating leases	697	1,096
Other assets	496	726
Total assets	699,488	806,879
Current liabilities:
Accounts payable	6,074	9,018
Accrued external research and development expenses	16,321	11,451
Other accrued expenses	11,756	15,561
Operating lease liabilities, current	209	611
Total current liabilities	34,360	36,641
Long-term debt, net	59,745	29,159
Operating lease liabilities, non-current	1,133	1,253
Total liabilities	95,238	67,053
Commitments and contingencies (Note 14)
Stockholders' equity:
Preferred stock, $0.0001 par value; 10,000,000 shares authorized, no shares issued or outstanding as of September 30, 2026 and December 31, 2025	0	0
Common stock, $0.0001 par value; 100,000,000 shares authorized as of September 30, 2026 and December 31, 2025; 38,619,312 and 37,890,616 shares issued and outstanding as of September 30, 2026 and December 31, 2025, respectively	4	4
Additional paid-in capital	1,299,773	1,249,043
Accumulated other comprehensive (loss) income	(2,770)	965
Accumulated deficit	(692,757)	(510,186)
Total stockholders' equity	604,250	739,826
Total liabilities and stockholders' equity	$ 699,488	$ 806,879

The amount of accrued external research and development expenses current.

No definition available.

Name:	iron_AccruedExternalResearchAndDevelopmentExpensesCurrent
Namespace Prefix:	iron_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).