Study shows radioactive antibodies produce durable remissions of three years or more
NEW ORLEANS - A radioactive antibody compound known as Bexxar produced tumor shrinkage in 97 percent of 76 previously untreated patients with advanced-stage, low-grade non-Hodgkins lymphoma (NHL) in a new study at the University of Michigan Comprehensive Cancer Center.
Most notably, 76 percent of patients achieved a complete remission, with no sign of cancer. In addition, 84 percent of patients with evidence of lymphoma at the molecular level at the start of the trial achieved molecular remission for as long as three years with the treatment. Molecular remissions were determined by a rigorous use of polymerase chain reaction, or PCR, technology, arguably the most sensitive cancer detection method available today.
These promising results, from the first completed study of a first-line, stand-alone radioimmunotherapy for cancer, were presented today at the meeting of the American Society of Clinical Oncology by Mark S. Kaminski, M.D., U-M professor of hematology/oncology and co-director of the U-M's leukemia/lymphoma and bone marrow transplant programs.
The original studies in the therapeutic development of Bexxar, or Iodine I 131 tositumomab, were done at the U-M by Kaminski and his colleague Richard Wahl, M.D., professor of nuclear medicine and radiology. The therapy is now being jointly developed by Coulter Pharmaceutical, Inc. and SmithKline Beecham.
"We are extremely excited by these findings, which showed remarkable response rates and molecular remissions lasting up to and beyond three years," says Kaminski. "Molecular remissions are seldom seen with chemotherapy in low-grade lymphoma, and appear to coincide with prolonged, durable responses. Furthermore, these results demonstrate the potential of this treatment as an effective and well-tolerated first-line, single-agent treatment for low-grade lymphoma, a disease without a known cure."