ImmunoGen Inc.'s Oncolysin B monoclonal antibody resulted incomplete remission of disease in 32 of 41 patients (78 percent)with B cell lymphoma who have undergone autologous bonemarrow transplantation.

Preliminary data from the Phase II trial was presentedTuesday at the American Society of Hematology's annualmeeting in St. Louis. The median time from transplant for thesepatients was 16 months.

Immunogen's vice president and chief medical officer, CarolEpstein, noted that "only 30 to 50 percent of ABMT patientswould be expected to be free of disease after two years."

Of 33 patients, nine developed human anti-mouse antibodies(HAMA) and/or human anti-ricin antibodies (HARA).Thrombocytopenia occurred in two patients. Other reversibletoxicities included edema, dyspnea, fatigue, myalgias, vomitingand mild capillary-leak syndrome with hypoalbuminemia.

Epstein also presented further follow-up data on a Phase I/IItrial. Ten of 12 patients treated with Oncolysin post-ABMTremain in complete remission with a median time fromtransplant of 33 months.

Oncolysin B is comprised of the anti-B4 monoclonal antibodyand the modified plant toxin "blocked ricin." The immunotoxinis directed to CD19+ cells and delivers the toxic portion ofblocked ricin to the cytoplasm, where it inhibits proteinsynthesis.

In poster sessions, ImmunoGen (NASDAQ:IMGN) of Cambridge,Mass., also presented in vitro and in vivo data on the cytotoxiceffects of combining Oncolysin B with chemotherapeutic drugs.The company found that the combination improved the meansurvival time in a Namalwa/SCID mouse model.

-- Brenda Sandburg News Editor

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