biostudies-literatureUnknown33(3)Powers TWThe multi-attribute method (MAM), a mass spectrometry technique for quantifying amino acid modifications at the peptide level, is becoming a prominent analytical tool in the development of biotherapeutics. The method has promise for adeno-associated virus (AAV) therapeutics, where capsid protein modifications have been directly linked to reduced transduction efficiency. Given this link, a robust and precise procedure to quantitate capsid modifications would be beneficial for implementation throughout biotherapeutic development. Herein, an AAV product was characterized, and capsid sequence liabilities were identified. A peptide map MAM method was developed to quantitate select sites of modifications and was validated according to ICH Q2(R2). Through this exercise, the method was demonstrateMolecular therapy. Methods & clinical development101560https://www.ebi.ac.uk/biostudies/studies/S-EPMC12410397biostudies-literatureDevelopment and implementation of an LC-MS-based multi-attribute method for adeno-associated virus.PMC12410397Mariani SPowers TWNarepekha HSankar SRyan DLerch TFfalseDevelopment and implementation of an LC-MS-based multi-attribute method for adeno-associated virus.The multi-attribute method (MAM), a mass spectrometry technique for quantifying amino acid modifications at the peptide level, is becoming a prominent analytical tool in the development of biotherapeutics. The method has promise for adeno-associated virus (AAV) therapeutics, where capsid protein modifications have been directly linked to reduced transduction efficiency. Given this link, a robust and precise procedure to quantitate capsid modifications would be beneficial for implementation throughout biotherapeutic development. Herein, an AAV product was characterized, and capsid sequence liabilities were identified. A peptide map MAM method was developed to quantitate select sites of modifications and was validated according to ICH Q2(R2). Through this exercise, the method was demonstrate2025-01-01T00:00:00Z2025 Sep2026-06-01T13:59:59.113Z2026-04-08T13:14:05.618ZS-EPMC124103974091769310.1016/j.omtm.2025.101560