Annual report pursuant to Section 13 and 15(d)


Cover - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2021
Feb. 28, 2022
Jun. 30, 2021
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2021    
Current Fiscal Year End Date --12-31    
Document Transition Report false    
Entity File Number 001-37590    
Entity Registrant Name AVALO THERAPEUTICS, INC.    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 45-0705648    
Entity Address, Address Line One 540 Gaither Road    
Entity Address, Address Line Two Suite 400    
Entity Address, City or Town Rockville    
Entity Address, State or Province MD    
Entity Address, Postal Zip Code 20850    
City Area Code 410    
Local Phone Number 522-8707    
Title of 12(b) Security Common Stock, $0.001 Par Value    
Trading Symbol AVTX    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Non-accelerated Filer    
Entity Small Business true    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag false    
Entity Shell Company false    
Entity Public Float     $ 183.5
Entity Common Stock, Shares Outstanding   112,794,203  
Documents Incorporated by Reference The registrant intends to file a definitive proxy statement pursuant to Regulation 14A within 120 days after the end of the fiscal year ended December 31, 2021. Portions of such proxy statement are incorporated by reference into Part III of this Form 10-K.    
Entity Central Index Key 0001534120    
Document Fiscal Year Focus 2021    
Document Fiscal Period Focus FY    
Amendment Flag false