TREATMENT OF NON-HODGKINS-LYMPHOMA WITH RADIOLABELED MURINE, CHIMERIC, OR HUMANIZED LL2, AN ANTI-CD22 MONOCLONAL-ANTIBODY

LL2 is a murine IgG2a anti-CD22 monoclonal antibody found to react wit h virtually all non-Hodgkin's lymphomas (NHLs). Twenty-one patients wi th chemotherapy-resistant NHL received nonmyeloablative doses of I-131 -labeled LL2 IgG and F(ab')(2) ranging from 15 to 343 mCi given in cyc les of 15-50 mCi, for up to seven treatment cycles, The cumulative pro tein dose ranged from 1.1 mg IgG to 157 mg F(ab')(2), Seventeen patien ts were assessable for treatment response, and antitumor effects were seen in five (one complete remission, two partial remissions, and two minor or mixed responses), In addition, one complete response was seen in a patient who received only ''diagnostic'' doses of I-131-LL2 IgG. Thus, a total of six patients had responses according to the defined response criteria. Three additional patients have been treated with po tentially myeloablative doses of I-131-LL2 IgG at a starting dose leve l of 90 mCi/m(2) (100 mg), Two patients were evaluable, and both had p artial remissions lasting 8 and 3 months, respectively, Chimeric and c omplementarity-determining region-grafted LL2 have been developed, Ini tial clinical studies have shown that these agents have targeting prop erties similar to the murine LL2 and, therefore, may be suitable alter natives to murine LL2 in the treatment of NHL. LL2 is a promising agen t for the treatment of lymphoma, particularly when the maximum tolerat ed dose is given either with or without autologous bone marrow transpl antation.