v3.26.1
Document and Entity Information - shares
 6 Months Ended
Jun. 30, 2026
Aug. 03, 2026
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2026  
Document Transition Report false  
Entity File Number 001-41740  
Entity Registrant Name Apogee Therapeutics, Inc.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 93-4958665  
Entity Address, Address Line One 1 Letterman Drive  
Entity Address, Address Line Two Building B  
Entity Address, Address Line Three Suite B6-800  
Entity Address, City or Town San Francisco  
Entity Address State Or Province CA  
Entity Address, Postal Zip Code 94129  
City Area Code 650  
Local Phone Number 394‑5230  
Title of 12(b) Security Common Stock, par value $0.00001 per share  
Trading Symbol APGE  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Central Index Key 0001974640  
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2026  
Document Fiscal Period Focus Q2  
Amendment Flag false  
Former Address    
Entity Address, Address Line One 221 Crescent St.  
Entity Address, Address Line Two Bldg 17, Suite 102b  
Entity Address, City or Town Waltham  
Entity Address State Or Province MA  
Entity Address, Postal Zip Code 02453  
Voting Common Stock    
Entity Common Stock, Shares Outstanding   62,201,093
Nonvoting Common Stock    
Entity Common Stock, Shares Outstanding   13,486,642