BL-01, an Fc-bearing, tetravalent CD20 × CD5 bispecific antibody, redirects multiple immune cells to kill tumors in vitro and in vivo.

Background Aims: The authors describe here a novel therapeutic strategy combining a bispecific antibody (bsAb) with cytokine-induced killer (CIK) cells.

Methods: The authors have designed, produced and purified a novel tetravalent IgG1-like CD20 × CD5 bsAb called BL-01. The bsAb is composed of a fused heavy chain and two free light chains that pair correctly to the heavy chain sequences thanks to complementary mutations in the monoclonal antibody 2 CH1/CL sequences.