A gram-scale synthesis of β-L-carbafucose for engineering antibody glycans.

Afucosylated antibodies often exhibit superior properties compared to their fucosylated counterparts including, among others, enhanced antibody-dependent cell cytotoxicity (ADCC). While several recombinant and biochemical strategies have been identified for generating afucosylated antibodies, small molecule metabolic inhibitors provide a potentially more straightforward option. We recently reported that β-L-carbafucose is an inhibitor of antibody fucosylation and is not incorporated into the antibody glycans. To support the further study of β-L-carbafucose, a gram-scale synthesis was needed. Here, we report our investigation of three distinct synthetic routes, including a highly efficient chromatography-free synthesis. Further, we demonstrate multi-gram production of afucosylated Herceptin (Trastuzumab®) in 10 L bioreactors using β-L-carbafucose. We expect this new synthetic process will support the widespread adoption of β-L-carbafucose for producing afucosylated antibodies for discovery and development purposes.