Unaudited Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Current assets:
Cash and cash equivalents	$ 15,591	$ 18,860
Prepaid expenses and other current assets	914	830
Assets held for sale	0	86
Total current assets	16,505	19,776
Restricted cash	50	50
Total assets	16,555	19,826
Current liabilities:
Accounts payable	107	164
Accrued expenses	858	2,037
Purchase warrant liability	5,265	4,874
Total current liabilities	6,230	7,075
Long-term liabilities:
Commitments and contingencies (Note 11)
Stockholders' equity
250,000,000 shares authorized as of September 30, 2025 and December 31, 2024; 11,978,711 shares issued and 11,698,919 shares outstanding as of September 30, 2025 and 11,975,901 shares issued and 11,696,109 shares outstanding as of December 31, 2024	12	12
Additional paid-in capital	456,995	456,908
Accumulated other comprehensive income	0	0
Accumulated deficit	(444,164)	(441,651)
Treasury stock, at cost (279,792 shares at September 30, 2025 and at December 31, 2024)	(2,518)	(2,518)
Total stockholders' equity	10,325	12,751
Total liabilities and stockholders' equity	$ 16,555	$ 19,826

Purchase Warrant Liability

No definition available.

Name:	sybx_PurchaseWarrantLiability
Namespace Prefix:	sybx_
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).