Condensed Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
Jun. 30, 2026	Jun. 30, 2025
Cash flows from operating activities
Net loss	$ (36,819)	$ (20,328)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	494	132
Stock-based compensation expense	13,106	2,910
Non-cash operating lease costs	1,595	135
Amortization of premiums and discounts on short-term investments, net	(250)	0
Changes in operating assets and liabilities:
Prepaid assets	(2,971)	(829)
Other current assets	(5,024)	(1,302)
Accounts payable	(885)	(221)
Accrued liabilities	4,334	3,171
Accrued compensation	815	1,236
Lease liabilities	(2,026)	(1,919)
Deferred revenues	(7,639)	(5,421)
Other long-term liabilities	201	(574)
Net cash used in operating activities	(35,069)	(23,010)
Cash flows from investing activities
Purchases of short-term investments	(191,551)
Purchases of property and equipment	(2,134)	(266)
Net cash used in investing activities	(193,685)	(266)
Cash flows from financing activities
Net transfers from Former Parent	301,505	23,276
Net cash provided by financing activities	301,505	23,276
Net increase in cash, cash equivalents, and restricted cash	72,751	0
Cash, cash equivalents and restricted cash, at beginning of period	0	0
Cash, cash equivalents and restricted cash, at end of period	72,751	0
Reconciliation of cash, cash equivalents and restricted cash, at end of period:
Cash and cash equivalents	72,334	0
Restricted cash included in current assets	311	0
Restricted cash included in non-current assets	106	0
Total cash, cash equivalents and restricted cash	72,751	0
Supplemental schedule of noncash investing and financing activities:
Costs incurred, but not paid, in connection with purchases of property and equipment included in accounts payable and accrued liabilities	0	109
Net assets distributed from Former Parent	0	742
Reclassification of deficit from Former Parent	$ 221,940	$ 0

Reclassification of deficit from Former Parent.

No definition available.

Name:	rna_ReclassificationOfDeficitFromFormerParent
Namespace Prefix:	rna_
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.