Long-term responses in patients with recurring or refractory B-cell non-Hodgkin lymphoma treated with yttrium 90 ibritumomab tiuxetan.
BACKGROUND
Radioimmunotherapy with radiolabeled monoclonal antibodies to CD20 produces a high response rate in patients with recurring non-Hodgkin lymphoma (NHL), but the durability of those remissions is not well defined.


METHODS
Data on patients with recurring NHL treated with yttrium Y 90 ibritumomab tiuxetan in 4 clinical trials were reviewed to identify patients with a long-term response, defined as a time to progression of 12 months or longer.


RESULTS
Long-term responses were seen in 37% (78/211) of patients. At a median follow-up of 53.5 months (range, 12.7-88.9) the median duration of response was 28.1 months and the median time to progression was 29.3 months. A third of these patients had been treated with at least 3 previous therapies, and 37% of them had not responded to their last therapy. The findings in patients with follicular lymphoma (n=59) were similar to those in the overall population of long-term responders. The estimated overall survival at 5 years was 53% for all patients treated with 90Y ibritumomab tiuxetan and 81% for long-term responders.


CONCLUSIONS
A single dose of 90Y ibritumomab tiuxetan can produce durable responses and prolonged overall survival in a substantial number of patients in whom previous therapies have failed.
Witzig
Thomas E
TE
Department of Internal Medicine, Division of Hematology, Mayo Clinic, Rochester, Minnesota 55905, USA. thomas@mayo.edu
Molina
Arturo
A
Gordon
Leo I
LI
Emmanouilides
Christos
C
Schilder
Russell J
RJ
Flinn
Ian W
IW
Darif
Mohamed
M
Macklis
Roger
R
Vo
Katie
K
Wiseman
Gregory A
GA
D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D058846:Antibodies, Monoclonal, Murine-Derived; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D019008:Drug Resistance, Neoplasm; D006801:Humans; D018796:Immunoconjugates / Q000627:therapeutic use; D016393:Lymphoma, B-Cell / Q000188:drug therapy / Q000401:mortality / Q000532:radiotherapy*; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy / Q000401:mortality; D016499:Radioimmunotherapy / Q000379:methods*; D000069283:Rituximab; D015021:Yttrium Radioisotopes / Q000627:therapeutic use*
D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D000970:Antineoplastic Agents; D018796:Immunoconjugates; D015021:Yttrium Radioisotopes; D000069283:Rituximab; C422802:ibritumomab tiuxetan