Nicolas Schneider¹, Morgan Mathieu², Sandra Savard-Chambard Gas¹, Angélique Boedec Herbette¹, Hélène Rispaud¹, Naouel Lovera¹, Delphine Bregeon¹, Agnès Represa¹, Christian Belmant^1
1 Innate Pharma, Marseille, France
² Enzo Life Sciences, Lausen, Switzerland

Featured Product: PROTEOSTAT® Protein Aggregation Standards (IgG), PROTEOSTAT® Protein Aggregation Assay, PROTEOSTAT® Thermal Shift Stability Assay

Abstract

Innate Pharma has developed an antibody-drug conjugate (ADC) coupling technology. The stability of unglycosylated SGN30 Q and S mutants coupled to the MMAE toxin by either one-step (SGN30 Q/S-linker-vcMMAE) or two-step technology (SGN30 Q/S-Linker-Click-Linker-vcMMAE) was compared to the first FDA-approved ADC, ADCETRIS®, and evaluated to validate the technology concept for clinical applications. The temperatures of aggregation, determined via the PROTEOSTAT® Thermal Shift Assay, established the following aggregation propensity prediction ladder: SGN30 Q ADCs coupled with four MMAE toxins are less stable than SGN30 S ADCs coupled with only two MMAE toxins; ADCs coupled with lipophilic linkers are less stable than ADCs coupled with hydrophilic ones; and ADCETRIS® is more stable than a SGN30 Q ADC coupled to a lipophilic linker but less stable than a SGN30 Q ADC coupled with a hydrophilic one. An accelerated degradation study confirmed this hierarchy (with the exception of ADCETRIS® likely due to a higher fragmentation of its antibody element) and provided confirmation that the PROTEOSTAT® Thermal Shift Assay is predictive of aggregation propensity for ADC products.