CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
Jun. 30, 2025	Jun. 30, 2024
Cash flows from operating activities:
Net loss	$ (9,383)	$ (10,445)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation	769	691
Depreciation and amortization	87	91
Loss from equity method investment	0	100
Amortization/accretion on marketable securities	(61)	(285)
Changes in operating assets and liabilities:
Accounts receivable	399	0
Prepaid and other current assets	63	(352)
Other assets	90	83
Accounts payable, accrued liabilities and other liabilities	(1,322)	(2,193)
Net cash used in operating activities	(9,358)	(12,310)
Cash flows from investing activities:
Purchase of marketable securities	(9,180)	(28,515)
Sale of marketable securities	19,144	46,764
Purchase of property and equipment	(28)	0
Investment in Impilo Therapeutics	0	(100)
Net cash provided by investing activities	9,936	18,149
Cash flows from financing activities:
Proceeds from exercise of options	8	0
Tax withholding payments on net share settlement equity awards	(253)	(142)
Net proceeds from issuance of common stock	286	32
Net cash provided by (used in) financing activities	41	(110)
Effect of exchange rate changes on cash	7	(29)
Net increase in cash and cash equivalents	626	5,700
Cash and cash equivalents at beginning of period	16,209	22,593
Cash and cash equivalents at end of period	$ 16,835	$ 28,293

Increase Decrease In Accounts Payable Accrued Expenses And Other Liabilities

No definition available.

Name:	lsta_IncreaseDecreaseInAccountsPayableAccruedExpensesAndOtherLiabilities
Namespace Prefix:	lsta_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The sum of the periodic adjustments of the differences between securities' face values and purchase prices that are charged against earnings. This is called accretion if the security was purchased at a discount and amortization if it was purchased at premium. As a noncash item, this element is an adjustment to net income when calculating cash provided by or used in operations using the indirect method.