Unaudited Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2026	Dec. 31, 2025
Current assets:
Cash and cash equivalents	$ 13,183	$ 14,668
Prepaid expenses and other current assets	245	729
Total current assets	13,428	15,397
Restricted cash	50	50
Total assets	13,478	15,447
Current liabilities:
Accounts payable	80	103
Accrued expenses	1,036	915
Purchase warrant liability	345	2,566
Total current liabilities	1,461	3,584
Long-term liabilities:
Commitments and contingencies (Note 10)
Stockholders' equity
250,000,000 shares authorized as of June 30, 2026 and December 31, 2025; 11,978,711 shares issued and 11,696,641 shares outstanding as of June 30, 2026 and 11,978,711 shares issued and 11,698,919 shares outstanding as of December 31, 2025	12	12
Additional paid-in capital	457,041	457,025
Accumulated deficit	(442,518)	(442,656)
Treasury stock, at cost (282,070 shares at June 30, 2026 and 279,792 shares at December 31, 2025)	(2,518)	(2,518)
Total stockholders' equity	12,017	11,863
Total liabilities and stockholders' equity	$ 13,478	$ 15,447

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).