Haemolytic disease of the fetus and newborn can be prevented by giving RhD-negative mothers anti-D antibodies, but the standard product is made from donor plasma and is costly. Two monoclonal alternatives, Rhoclone and Trinbelimab, are widely used in low- and middle-income countries without FDA/EMA approval. Researchers analyzed both in the lab. They found the antibodies bind the same RhD epitope and share an identical protein sequence. They differ in fucosylation: 96% for Rhoclone versus 86% for Trinbelimab. Both triggered weaker natural killer cell-mediated killing (ADCC) than the polyclonal product Rhophylac. Activity tracked with fucose levels, and engineered low-fucose versions markedly outperformed the polyclonal product. Whether this translates into better clinical prevention remains untested.
