Results from a clinical trial presented at the American Society of Hematology 46th Annual Meeting and Exposition (ASH) demonstrated that Zevalin (ibritumomab tiuxetan), administered as a first-line therapy, induced a 100 percent response rate in a small population of patients with low-grate follicular lymphoma (FL).
"These data demonstrate Zevalin's effectiveness in the first-line treatment of previously untreated low grade follicular lymphoma patients," said John William Sweetenham, M.D., Professor of Medicine, University of Arizona Cancer Center, research conducted at the University of Colorado Health Sciences Center. "These results are exciting and further follow-up is needed to determine the long-term efficacy of combining frontline radioimmunotherapy with antibody-based maintenance."
Eight of the 10 patients treated with Zevalin were evaluated for treatment response. Of the eight patients, five (62 percent) had complete responses and three (38 percent) had partial responses to Zevalin induction therapy. Toxicities were manageable and primarily hematologic with grade three cytopenia occurring in 38 percent (3/8) of patients.
Patients were eligible for treatment if they presented with histologically confirmed, previously untreated low-grade FL. Additional eligibility criteria included stage III or IV disease and a need for therapeutic intervention because of constitutional symptoms, evidence of disease progression, or organ dysfunction directly attributable to NHL. Patients were excluded if there was evidence of histologic transformation to aggressive disease. The median age of patients was 58 years (range, 40 - 82) and 50 percent (5/10) of patients had stage IV disease. Delivered doses of 90Y ibritumomab tiuxetan ranged from 21-32 mCi.
On day one, patients received an initial infusion of rituximab (250 mg/m2) followed by an imaging dose of Indium 111 (111In) ibritumomab tiuxetan (5 mCi). One week later, a second infusion of rituximab (250 mg/m2) was given, proceeded by an injection of 90Y ibritumomab tiuxetan (0.3 or 0.4 mCi/kg, depending upon platelet count). Rituximab maintenance therapy (375 mg/m2 x 4) was scheduled at six-month intervals over two years. Endpoints included clinical response rates using standard International Workshop Response Criteria (IWRC) and toxicity.
Non-Hodgkin's lymphoma (NHL) is a type of malignant disease that occurs within the lymphatic system. It originates from lymphocytes, a type of white blood cells, which can be divided into two main types, B lymphocytes and T lymphocytes (also called B-cells or T-cells). In adults, approximately 85 percent of NHL cases are of B-cell origin.
The overall prevalence of NHL in the European Union is about 230,000 with an annual incidence of about 70,000. This incidence is currently increasing in Europe by four percent per year.