As if there were not enough companies generating antibodies, Avanir Inc. has formed subsidiary Xenerex Inc. to squeeze into the space with its own antibody producing mouse. Xenerex's twist is to graft human antibody-producing cells into mice rather than engineer the mice to express human genes, as do Abgenix Inc. and Medarex Inc.

The technology produces human antibodies by grafting human cells, either spleen or peripheral blood lymphocytes (PBLs), into immunodeficient SCID mice. The immune response generates human antibodies via somatic hypermutation, which Xenerex CEO David Hansen said maximizes the specificity and diversity of the antibodies.