v3.26.1
Document and Entity Information
 3 Months Ended
Mar. 31, 2026
Document Information [Line Items]  
Document Type S-1/A
Amendment Flag true
Amendment Description This Pre-Effective Amendment No. 1 to Form S-3 on Form S-1 is being filed by LeonaBio, Inc. (the “Company”) to convert the Registration Statement on Form S-3 (File No. 333-292829) filed by the Company with the Securities and Exchange Commission on January 20, 2026, into a registration statement on Form S-1.
Entity Registrant Name LeonaBio, Inc.
Entity Central Index Key 0001620463
Entity Primary SIC Number 2836
Entity Tax Identification Number 45-3368487
Entity Incorporation, State or Country Code DE
Entity Filer Category Non-accelerated Filer
Entity Small Business true
Entity Emerging Growth Company false
Entity Address, Address Line One 18706 North Creek Parkway
Entity Address, Address Line Two Suite 104
Entity Address, City or Town Bothell
Entity Address, State or Province WA
Entity Address, Postal Zip Code 98011
City Area Code 425
Local Phone Number 620-8501
Business Contact [Member]  
Document Information [Line Items]  
Contact Personnel Name Mark Litton, Ph.D.
Entity Address, Address Line One 18706 North Creek Parkway
Entity Address, Address Line Two Suite 104
Entity Address, City or Town Bothell
Entity Address, State or Province WA
Entity Address, Postal Zip Code 98011
City Area Code 425
Local Phone Number 620-8501