CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2026	Dec. 31, 2025
Current assets
Cash and cash equivalents	$ 32,286	$ 58,450
Marketable securities	288,075	189,656
Accounts receivable from collaboration with a related party	822	974
Prepaid expenses and other current assets	6,795	5,469
Total current assets	327,978	254,549
Property and equipment, net	315	221
Operating lease right-of-use (ROU) assets	2,227	2,508
Other assets	312	312
Total assets	330,832	257,590
Current liabilities
Accounts payable	1,180	1,171
Accrued research and development expenses	2,007	2,387
Other accrued expenses	3,342	7,749
Deferred revenue from a related party	16,304	36,904
Operating lease liabilities - short-term	612	569
Total current liabilities	23,445	48,780
Operating lease liabilities - long-term	1,738	2,059
Total liabilities	25,183	50,839
Commitments and contingencies
Stockholders' equity
Preferred stock, $0.001 par value; 5,000,000 shares authorized; no shares issued or outstanding
Common stock, $0.001 par value; 150,000,000 shares authorized as of June 30, 2026 and December 31, 2025; 19,850,342 and 15,855,329 shares issued and outstanding as of June 30, 2026 and December 31, 2025, respectively	20	16
Additional paid-in capital	1,151,235	1,038,823
Accumulated other comprehensive loss	(623)	(41)
Accumulated deficit	(844,983)	(832,047)
Total stockholders' equity	305,649	206,751
Total liabilities and stockholders' equity	$ 330,832	$ 257,590

Accrued research and development expenses current.

No definition available.

Name:	asmb_AccruedResearchAndDevelopmentExpensesCurrent
Namespace Prefix:	asmb_
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).