Patients treated with IDEC Pharmaceutical Corp.'s genetically-engineered antibody, IDEC-C2B8, in a Phase I clinical trialexperienced tumor shrinkage of their relapsed B-cell lymphomas in 11out of 18 cases.The results of the trial were presented at the annual meeting of theAmerican Society of Clinical Oncology (ASCO) in Dallas on Tuesday.IDEC-C2B8 is a genetically engineered, pan-B antibody that attachesto CD20 antigens on the surface of B cells, activating complementproteins and macrophages to attack and destroy malignant B-cells.Nine of the patients received the highest dose of the antibody.Of the 11 subjects whose tumors shrunk, seven had a partial responseto therapy (tumor shrinkage of more than 50 percent) and fourexperienced minor responses.Thirteen of the 18 patients had low-grade B-cell lymphoma, and 10 ofthem experienced tumor shrinkage, seven had partial response andthree had minor responses (tumor shrinkage greater than 25 percent butless than 50 percent).No quantifiable evidence of antibody rejection was observed, toxicityappeared to be low and the drug seemed to target only B-cells.IDEC, based in San Diego, said these results support the developmentof IDEC-C2B8 as a single-agent therapy for relapsed lymphomas. Itsaid the highest dose, 375 mg, will be selected as the full therapeuticdose for study in the Phase II portion of the trial now underway atseven centers.IDEC also has a Phase II trial underway to study IDEC-C2B8 incombination with chemotherapy.In other ASCO news:ImmunoGen Inc., of Cambridge, Mass. reported that its lead product,Oncolysin B, proved effective in preventing relapses of lymphomawhen administered to patients following autologous bone marrowtransplantation (ABMT). In the initial Phase I/II trial, 10 of 12 patientsremained free of disease for a median period of three years. Seventypercent of patients in the subsequent Phase II study of 50 patients,remain in remission with a median of 17 months. The company said aPhase III study is already underway at 23 cancer centers in the U.S. andCanada.
-- Philippa Maister
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