| Cover Page Document | Nov. 09, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Nov. 9, 2021 |
| Entity Registrant Name | AVALO THERAPEUTICS, INC. |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-37590 |
| Entity Tax Identification Number | 45-0705648 |
| Entity Address, Address Line One | 540 Gaither Road, 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 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $0.001 Par Value |
| Trading Symbol | AVTX |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0001534120 |
| Amendment Flag | false |
