Science et thérapie du cancer

A Case Report on Metastatic Thyroid Carcinoma: Radiation-induced Bystander or Abscopal Effect?

Abstract

Slavisa Tubin, Franco Casamassima, Claudia Menichelli, Gabriella Pastore, Alessandro Fanelli and Rossana Crisci

Purpose: Both anti-CD20 antibodies (ibritumomab; ZEVALIN® and tositumomab; BEXXAR®) currently used for radioimmunotherapy of B cell non-Hodgkin’s lymphoma are murine immunoglobulins. The aim of this feasibility study was to evaluate the safety and efficacy of radioimmunotherapy with a human chimeric anti-CD20 antibody labelled with Yttrium-90 (90Y-rituximab) in patients with B cell lymphoma.

Methods: Patients with CD20+ B-cell lymphoma in partial remission or with progressive disease after at least one line of therapy were included. 90Y-rituximab was administered according to a similar schedule as currently approved by the European Medicines Agency for the treatment with 90Y-ibritumomab tiuxetan (ZEVALIN®): a first infusion of rituximab 250 mg/m² is repeated one week later and directly followed by the injection of 90Y-rituximab (14,8 MBq/kg). 18FDG-PET/CT was performed before treatment and repeated 3 months after for response assessment.

Results: Twenty-six patients were treated with 90Y-rituximab. Disease histologies included mainly follicular lymphomas (53%). Toxicity was primarily haematological. The incidence of grade 3-4 neutropenia, thrombocytopenia and anemia were 34%, 38%, and 8% respectively, with spontaneous recovery in all but one patient that needed autologous stem cell transplant for refractory thrombocytopenia. Among the relevant long-term side effects, one patient developed secondary myelodysplasia 2 years after the treatment. The overall response rate was 88% (95% CI: 70%-98%), including 65% complete metabolic responses and 23% partial metabolic responses. After a median follow-up of 29.6 months, the Kaplan-Meier estimated median progression-free survival was 9, 1 months (95% CI 6,1-17,9). Median time to next treatment was 24 months (95% CI: 12, 2-28).

Conclusion: Radioimmunotherapy with 90Y-rituximab in patients with relapsed CD20+ B-cell lymphomas is safe, well tolerated and effective when the ZEVALIN® treatment schedule is used.