Efficacy and safety of yttrium-90 ibritumomab tiuxetan in the treatment of non-Hodgkin lymphoma.

Abstract

103 Background: Yttrium 90-labeled ibritumomab tiuxetan (Zevalin) is a radioimmunotherapy agent which combines the action of a beta-emitting isotope, yttrium-90, with the anti-CD20 monoclonal antibody, rituximab. The purpose of this study was to evaluate the efficacy of Zevalin in the treatment of Non-Hodgkin Lymphoma (NHL) in terms of response to therapy, overall survival (OS) and progression free survival (PFS). Methods: A total of 171 patients with NHL referred for treatment with Zevalin between September 2005 and January 2017 were identified for retrospective analysis. Clinical characteristics, treatments, and outcomes were extracted from clinical chart review. Survival rates and survival curves were generated using Kaplan-Meier analysis. Chi-square and independent student t test were used for comparison of categorical variables. Multivariate analysis (MVA) Cox proportional hazards ratios (HR) model was used to assess OS and PFS. Results: Of the 171 patients referred for treatment, median age was 70 years old, 54% were male (n = 93), and each patient had received a median of 2 prior chemotherapy regimens. The majority of patients were treated for follicular lymphoma (n = 107) and diffuse large B-cell lymphoma (n = 34). Seventy-three patients (53%) achieved complete response, and 23 patients achieved partial response (17%). One-year progression free survival was 71%, and median PFS was 31 months. Adverse events included cytopenic events, GI side effects, and mucocutaneous toxicity. Conclusions: Use of Zevalin for treatment of NHL demonstrated a significant improvement in PFS. In addition to improved efficacy, Zevalin was well-tolerated in this study and demonstrated an adequate safety profile. Further considerations will be given as to which treatment factors are associated with a complete response and improved PFS.