BUFFALO, NY--Adding a chimeric anti-CD20 antibody to standard
CHOP chemotherapy appears to produce a synergistic therapeutic
effect in low-grade B-cell lymphomas. Patients on the regimen
have achieved complete remissions and disappearance of the bcl-2
translocation, principal investigator Myron Czuczman, of the Roswell
Park Cancer Institute, said at the annual Chemotherapy Foundation
Preliminary results of an ongoing pilot phase II trial show a
100% response rate in 16 evaluable patients (11 complete responses
and 5 partial responses), with all responses ongoing at 5 to 18
months. Moreover, of the four patients whose bcl-2 status was
known prior to therapy, all became bcl-2 negative by completion
The antibody (IDEC-C2B8, from IDEC Pharmaceuticals Corporation,
San Diego) targets the CD20 antigen, which is expressed on the
surface of mature B cells and on B-cell tumors, but not on B-cell
precursors or on plasma cells.
IDEC-C2B8 binds to its target antigen and recruits host defenses
to attack and kill both malignant and normal B cells. After treatment,
the normal B cells regenerate from stems cells within months,
without damage to the marrow.
In the ongoing trial, patients are given IDEC-C2B8 at a dose of
375 mg/m2 on weeks 1 (two doses), 7, 13, 20, and 21, for a total
of six doses. CHOP (cyclophosphamide, doxorubicin, vincristine,
and prednisone) is given on weeks 2, 5, 8, 11, 14, and 17, for
a total of six cycles.
Forty patients have been enrolled in the study to date, and data
were reported for 27 of these patients, 16 of whom have completed
all scheduled therapy.
The trial is being conducted at Roswell Park Cancer Institute,
Northwestern University, the University of Alabama at Birmingham,
and the Sharp Health Care and Sidney Kimmel Cancer Center in San