RO5486055

RO5486055 is a fully humanized monoclonal antibody developed by Roche that selectively targets and neutralizes hepsin (a type II transmembrane serine protease). Hepsin is overexpressed in prostate, breast, and other cancers, where it is implicated in promoting tumor growth, invasion, and metastasis. RO5486055 selectively binds to hepsin, inhibiting its serine protease activity with single-digit nanomolar potency, which leads to the accumulation of its substrate laminin-332 (specifically the beta-3 chain). In preclinical studies, RO5486055 has demonstrated dose-dependent exposure, a long serum half-life, and significant tumor growth inhibition in prostate and breast cancer xenograft models, particularly when combined with other therapies such as cetuximab or hormone withdrawal.