Epratuzumab Plus Rituximab and Chemotherapy Is Active, Safe, and Tolerable in Aggressive Lymphoma

Immunomedics, Inc. a biopharmaceutical company focused on developing monoclonal antibodies to treat cancer and other serious diseases, today announced that adding epratuzumab (LymphoCIDE) to rituximab (Rituxan) and combined cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy (ER-CHOP) for the therapy of patients with newly diagnosed diffuse large B-cell lymphoma (DLBCL) produced promising results.

Seventy-eight patients with previously untreated DLBCL were eligible to participate in this phase II open-label study led by Mayo Clinic, Rochester, Minn. The primary endpoint of this study is event-free survival (EFS) at 12 months with planned interim analysis after 34 evaluable patients. At the time of reporting, EFS for 34 interim analysis patients was 85% (29 out of 34). Overall, 95% of patients responded (72 out of 76), including 47 complete responses (62%) and 25 partial responses (33%).

Interim results show that the overall response rate and EFS at 12 months for ER-CHOP, in comparison to R-CHOP, are promising. If the final study analysis on all patients, which should be available by the end of 2008, remains promising, a randomized phase III trial would be needed to definitely assess whether ER-CHOP is more effective than R-CHOP.

Patients received epratuzumab at 360 mg/m2, followed by rituximab at 375 mg/m2, and a standard dose of CHOP every 3 weeks for six cycles. The ER-CHOP regimen, which was easily administered to patients, was found to be safe with little added toxicity over R-CHOP.

Past and Ongoing Investigations
Results from the feasibility phase of this study on 15 patients had been reported in Cancer in 2006 by Mayo Clinic. Overall response rate was 87% (13 out of 15) with event-free survival and overall survival at 1 year of 93% and 100%, respectively.

Epratuzumab is being studied in three National Cancer Institute–sponsored clinical trials involving the North Cancer Center Treatment Group, the Children's Oncology Group, and the Cancer and Leukemia Group B. Two prior trials published in the Journal of Clinical Oncology in 2005 and 2006 showed that epratuzumab can be combined with rituximab safely, with a suggestion of improved complete and durable response rates in patients with indolent and aggressive non-Hodgkin's lymphoma types.