Zevalin Effective In Stem Cell Transplantation For Non-Hodgkin's Lymphoma
Two studies are investigating the potential utility of Zevalin (Ibritumomab Tiuxetan) radioimmunotherapy as replacement for external beam radiations or supplement to high-dose chemotherapy in the treatment of non-Hodgkin's lymphoma (NHL).
"These two studies add to the increasing body of data suggesting that radioimmunotherapy may be a useful adjunct to stem cell transplantation in late stage non-Hodgkin's lymphoma. It appears not to delay engraftment or add substantially to the toxicities of high dose chemotherapy," said Jack W. Singer, M.D., Chief Medical Officer at CTI. "Controlled studies to determine the actual risk and benefit of RIT in this setting are warranted."
Phase I Trial of (90)Yttrium Ibritumomab Tiuxetan (RIT) with Autologous Stem Cell Transplantation (ASCT) in Patients with Relapsed or Refractory B-cell Non-Hodgkin's Lymphoma, Abstract 8565
In the phase I trial, 24 relapsed or refractory low-grade B-cell NHL patients, who had received a median of three prior regimens, were treated with escalating doses of RIT based on patient-specific organ dosimetry. Of the 18 patients treated with RIT as single-agent salvage therapy, 13 (72 percent) achieved a complete response (CR) and three patients achieved a partial response (PR). Median time to progression (TTP) was estimated to be nine months, which did not appear to differ regardless of RIT dose. The investigators concluded that patient-specific, organ dosimetry-based significant dose escalation with RIT was achieved with outpatient ASCT support. The maximum tolerated dose (MTD) was not reached in the study. These data indicate that the dose of (90)Yttrium used with the Zevalin regimen can be escalated provided there is a stem cell rescue.
Yttrium Ibritumomab Tiuxetan Combined with High-dose BEAM Chemotherapy and Autologous Stem Cell Transplantation for Relapsed/Refractory B-cell Non-Hodgkin's Lymphoma, Abstract 8615
The goal of this phase II trial was to evaluate the safety and efficacy of combining RIT with high-dose carmustine, cytarabine, etoposide, and melphalan (BEAM) chemotherapy and ASCT in patients with relapsed or refractory NHL. With a median follow up of 11 months, results from the first ten patients showed adverse events were similar to those seen with high-dose BEAM alone. The authors concluded that these preliminary results suggest that the combination of RIT and BEAM followed by ASCT is does not add significantly to the toxicity of BEAM alone and the combination is effective therapy.
Zevalin (Ibritumomab Tiuxetan) is a form of cancer therapy called radioimmunotherapy and is indicated as part of the Zevalin therapeutic regimen for treatment of relapsed or refractory, low-grade or follicular B-cell non-Hodgkin's lymphoma, including patients with rituximab refractory follicular NHL. It was approved by the FDA in February of 2002 as the first radioimmunotherapeutic agent for the treatment of NHL.
Rare deaths associated with an infusion reaction symptom complex have occurred within 24 hours of rituximab infusions. Yttrium-90 Zevalin administration results in severe and prolonged cytopenias in most patients. Severe cutaneous and mucocutaneous reactions have been reported. The most serious adverse reactions of the Zevalin therapeutic regimen were primarily hematologic, including neutropenia, thrombocytopenia, and anemia. Infusion- related toxicities were associated with pre-administration of rituximab. The risk of hematologic toxicity correlated with the degree of bone marrow involvement prior to Zevalin therapy. Myelodysplasia or acute myelogenous leukemia was observed in 2 percent of patients (8 to 34 months after treatment). Zevalin should only be used by health care professionals qualified by training and experience in the safe use of radionuclides.