v3.26.1
Document and Entity Information
Aug. 13, 2026
Cover [Abstract]  
Amendment Flag false
Entity Central Index Key 0002093101
Document Type 8-K
Document Period End Date Aug. 13, 2026
Entity Registrant Name Atrium Therapeutics, Inc.
Entity Incorporation State Country Code DE
Entity File Number 001-43008
Entity Tax Identification Number 39-4639499
Entity Address, Address Line One 10578 Science Center Drive
Entity Address, Address Line Two Suite 125
Entity Address, City or Town San Diego
Entity Address, State or Province CA
Entity Address, Postal Zip Code 92121
City Area Code (619)
Local Phone Number 876-0700
Written Communications false
Soliciting Material false
Pre Commencement Tender Offer false
Pre Commencement Issuer Tender Offer false
Security 12b Title Common stock, par value $0.001 per share
Trading Symbol RNA
Security Exchange Name NASDAQ
Entity Emerging Growth Company true
Entity Ex Transition Period false