Effect of a CrossMab cotargeting CD20 and HLA-DR in non-Hodgkin lymphoma.

To evaluate the anti-tumor activities of CD20/HLA-DR CrossmabCH1-CL through cell and animal models. Based on "knobs-into-holes" and "crossover" technology, CrossMab, targeting CD20 and HLA-DR, was constructed. A binding assay and a competitive inhibition assay were performed to confirm its specificity. The effects of CrossMab on antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity were measured. Cell apoptosis, lysosome-mediated cell death, and lysosomal permeability were quantified. In addition, the effects of CrossMab on peripheral blood leukocytes were tested. The pharmacokinetics were determined with a noncompartmental analysis model. Human malignant lymphoma xenograft models in CB17-SCID mice were established for an in-vivo efficacy study. The antitumor activities of CrossMab were shown both in vitro and in vivo. CrossMab exhibited strong binding to CD20 and HLA-DR at the same time in Raji cells. CrossMab also demonstrated antilymphoma effects by inducing antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity. Furthermore, CrossMab altered the lysosomal membrane permeability. The toxicity of CrossMab on normal peripheral blood lymphocytes (PBLs) was specific to B cells. A mouse xenograft model demonstrated the antitumor activities of CrossMab in vivo. CrossMab exhibited an enhanced antigen recognition ability and antitumor activities in lymphoma without evident toxicity. CrossMab could be an effective immunotherapeutic strategy for non-Hodgkin lymphoma. [ABSTRACT FROM AUTHOR]