Long-Term Follow-Up of 90Y-Ibritumomab Tiuxetan, Fludarabine, and Total Body Irradiation-Based Nonmyeloablative Allogeneic Transplant Conditioning for Persistent High-Risk B Cell Lymphoma

Abstract

Nonmyeloablative allogeneic hematopoietic cell transplantation (HCT) can provide prolonged remissions in patients with advanced B cell lymphoma (B-NHL) via the graft-versus-lymphoma effect, although inferior results are seen in patients with chemoresistant, bulky, or aggressive disease. Radioimmunotherapy can safely induce responses in B-NHL with minimal nonhematologic toxicity. Initial results of 90Y-ibritumomab tiuxetan-based allografting demonstrated early safety and disease control in nonremission patients but with short follow-up. Here we report the long-term outcomes of patients treated on this study with specific emphasis on patients achieving early remissions. Eleven of 40 patients were alive at a median follow-up of 9 years (range, 5.3 to 10.2). Fourteen (35%) deaths were due to disease progression and 14 (35%) deaths to complications from HCT. One patient died of a Merkel cell carcinoma. The 5-year overall and progression-free survival for patients with indolent B-NHL was 40% and 27.5%, respectively. None of the patients with diffuse large B cell lymphoma was a long-term disease-free survivor regardless of early remission status. 90Y-ibritumomab tiuxetan-based allografting represents a viable option in patients with indolent histologies. Improved strategies are needed for aggressive B-NHL. The original trial was registered at www.clinicaltrials.gov as NCT00119392.

Keywords: (90)Y-ibritumomab tiuxetan; Allogeneic transplant; B cell lymphoma; Long-term follow-up; Radioimmunotherapy; Zevalin.

Conflict of interest statement

Conflict-of-interest disclosure: A.K.G. has received research support from and served as a consultant for Biogen-Idec and Spectrum Pharmaceuticals

Copyright © 2018. Published by Elsevier Inc.

Figures

Figure 1:. Treatment Schema.

PBSC: peripheral blood stem cell. MMF: mycophenolate mofetil. TBI: total body irradiation.

Figure 2:. PFS and OS of entire cohort.

Kaplan-meier curve of progression-free and overall survival of entire cohort.

Figure 3:. PFS by histology.

Progression-free survival based on histology. Indolent includes CLL/SLL, FL and MZL. Aggressive includes DLBCL.

Figure 4:. PFS by early response.

Progression-free survival based on month 3 response. CR/CRu: complete response (unconfirmed). PR: Partial response.

Figure 5:

Non-relapse mortality and donor type. Cumulative incidence of non-relapse mortality stratified by donor type. MURD: matched unrelated donor. MRD: matched related donor.