RTX-M-GB

RTX-M-GB is an experimental antibody-drug conjugate (ADC) composed of the anti-CD20 monoclonal antibody rituximab (RTX) conjugated to M-GB, a modified small molecule inhibitor of cysteine cathepsins. The payload, M-GB, is a maleimide-functionalized derivative of GB111-NH2, a potent broad-spectrum inhibitor of proteases such as Cathepsin L, Cathepsin B, and Cathepsin S. RTX-M-GB is designed to target CD20-expressing malignant B cells, specifically in the context of diffuse large B-cell lymphoma (DLBCL) and chronic lymphocytic leukemia (CLL). Upon binding to CD20 and subsequent internalization, the cathepsin inhibitor payload is released within the lysosomal compartment, where it triggers apoptosis and caspase-3 activation. This therapeutic strategy is being investigated as a preclinical proof-of-concept to overcome rituximab resistance by delivering a novel protease-inhibitor payload directly to malignant cells.

Other names

Rituximab-M-GBRituximab-cathepsin inhibitor conjugateRituximab-GB111-NH2 conjugateRituximab-GB-111-NH2 conjugateRituximab-GB 111-NH2 conjugate