AYAT ABBOOD
Acta Pharmaceutica Sciencia - 2024;62(1):226-239
This study aimed to evaluate the charge variant profile of antibody-tomaymycin conjugates using an imaged capillary isoelectric focusing method (icIEF). Two unconjugated antibodies were examined, along with two conjugation methods involving cleavable and non-cleavable linkers. The cleavable linker contained one amine group. mAb-1 demonstrated greater homogeneity with a single main peak at a pI of 8.5, whereas mAb-2 exhibited two main peaks at pI values of 8.95 and 9.00. Conjugation with tomaymycin molecules resulted in an increased charge heterogeneity of both cleavable and non-cleavable conjugates. The non-cleavable conjugates displayed a higher number of additional acidic variants (pI range: 7.4 to 8.4 for mAb-1 and 8.2 to 8.9 for mAb-2) compared to the cleavable conjugates (pI range: 7.8 to 8.4 for mAb-1 and 8.4 to 8.9 for mAb-2). The linker nature had a lesser influence on the charge heterogeneity of the antibody-tomaymycin conjugates compared to the nature of the unconjugated antibody.
