We report the use of a bispecific F(ab')(2) antibody to target the rib
osome-inactivating protein saporin to the surface antigen CD22 in the
treatment of low-grade, end-stage, B-cell lymphoma. Four patients were
treated. Toxic effects were minimal (grade I), with mild fever, weakn
ess, and myalgia for 1-2 days after treatment. One patient showed an a
ntibody response to mouse Fab' and saporin. All patients showed rapid
and beneficial responses to treatment with improvements in most diseas
e sites and in peripheral blood cytopenia. The responses were short-li
ved (less than 28 days) but further study of this targeting system is
warranted.