IDEC-C2B2 is a chimeric monoclonal antibody (MoAb) directed against the B-cell specific antigen CD20 expressed on non-Hodgkin's lymphomas (NHL). The MoAb mediates complement and antibody dependent cell mediated cytotoxicity and has direct antiproliferative effects against malignant B-cell lines in vitro. Phase I trials of single doses up to 500mg/m2 and 4 weekly doses of 375 mg/m2 showed clinical responses with no dose limiting toxicity. We conducted a phase II, multicenter study evaluating four weekly infusions of 375 mg/m2 IDEC-C2B2 in patients with relapsed low grade or follicular NHL (working formulation groups A-D). Patients were monitored for adverse events, antibody pharmacokinetics and clinical response. Thirty seven patients with a median age of 58 years (range, 29 to 81 years) were treated. All patients had relapsed after chemotherapy (median of 2 prior regimens) and 54% had failed aggressive chemotherapy. Infusional side effects (grade 1-2) consisting of mild fever, chills, respiratory symptoms, and occasionally hypotension were observed mostly with the intial antibody infusion and were rare with subsequent doses. Peripheral blood B-cell depletion occurred rapidly, with recovery beginning 6 months posttreatment. There were no significant changes in mean lgG levels and infections were not increased over what would be expected in this population. Clinical remissions were observed in 17 patients (3 complete remissions and 14 partial rmissions), yielding an intent to treat response rate of 46%. The onset of these tumor responses was as soon as 1 month posttreatment and reached a maximum by 4 months posttreatment. In the 17 responders, the median time to progression was 10.2 months(5 patients exceeding 20 months). Likelihood of tumor response was associated with a follicular histology, with the ability to sustain a high serum level of antibody after the first infusion, and with a longer duration of remission to prior chemotherapy. One patient developed a detectablebut not quantifiable immune response to the antibody that had no clinical significance. IDEC-C2B2 in a dose of 375 mg/m2 weekly for 4 weeks has antitumor activity in patients with relapsed low grade or follicular NHL. Results with this brief, outpatient treatment compare favorably with results with standard chemotherapy and IDEC-C2B2 has a better safety profile. Further studies evaluating IDEC-C2B2 in other types of lymphoma either alone or combined with chemotherapy are warranted.
Mendeley saves you time finding and organizing research
There are no full text links
Choose a citation style from the tabs below