Treatment with Zevalin (ibritumomab tiuxetan), which combines an antibody with a radioactive agent, was found to be safe, reduced tumor burden in most patients, and significantly improved survival without disease worsening in people with non-Hodgkin’s lymphoma (NHL), a retrospective study reports.
The findings were presented during the 2020 American Society of Clinical Oncology and Society for Immunotherapy of Cancer Clinical Immuno-Oncology Symposium, in early February, in the poster session titled “Efficacy and safety of yttrium-90 ibritumomab tiuxetan in the treatment of non-Hodgkin lymphoma.”
Zevalin, marketed by Spectrum Pharmaceuticals, is an immunotherapy that combines the radioactive Yttrium-90 molecule with a cancer-targeting antibody. It is approved in combination with rituximab for certain follicular lymphoma and low-grade NHL patients.
Zevalin became the only radioimmunotherapy treatment in 2002 to be approved by the U.S. Food and Drug Administration (FDA) to treat patients with relapsed or refractory low-grade, or follicular NHL, including patients with follicular lymphoma who no longer responded to treatment with rituximab.
The FDA expanded the approval in 2009 to include patients with newly-diagnosed follicular lymphoma, who achieved a partial or complete response to first-line chemotherapy. The European Medicines Agency approved Zevalin in 2004 for the same indications.
In the new study, researchers investigated Zevalin’s efficacy in a real-world setting in people with non-Hodgkin’s lymphoma. Their analysis included 171 patients, who were referred to treatment with Zevalin between September 2005 and January 2017.
Among the patients, the median age was 70, about half (54%) were male, and they had undergone a median of two prior chemotherapy treatments. Most of these patients had either follicular lymphoma (107 patients) or diffuse large B-cell lymphoma (34). NHL type was not disclosed for the other 30 patients.
Overall, 70% of patients experienced a significant reduction in tumor burden, including 53% complete responses, or clearance of all cancer signs, and 17% partial responses.
The median time patients lived without disease worsening — a measure called progression-free survival (PFS) — was 31 months, and 70% of patients remained alive and without any signs of disease progression for at least one year. This is a “significant improvement in PFS,” the researchers wrote.
The treatment was deemed safe and well-tolerated as well, with the most common adverse events being an abnormally lower number of blood cells (cytopenia), gastrointestinal problems, and toxicity of the skin and mucosa, which can occur in the form of cell death, erosion, or ulcers.
“Further considerations will be given as to which treatment factors are associated with a complete response and improved PFS,” the researchers said.
