High-dose [131I]tositumomab (anti-CD20) radioimmunotherapy and autologous hematopoietic stem-cell transplantation for adults > or = 60 years old with relapsed or refractory B-cell lymphoma.
OBJECTIVE
The majority of patients with relapsed or refractory B-cell non-Hodgkin's lymphoma (NHL) are older than 60 years, yet they are often denied potentially curative high-dose therapy and autologous stem-cell transplantations (ASCT) because of the risk of excessive treatment-related morbidity and mortality. Myeloablative anti-CD20 radioimmunotherapy (RIT) can deliver curative radiation doses to tumor sites while limiting exposure to normal organs and may be particularly suited for older adults requiring high-dose therapy.


METHODS
Patients older than 60 years with relapsed B-cell NHL (B-NHL) received infusions of tositumomab anti-CD20 antibody labeled with 185 to 370 Mbq (5 to 10 mCi) [131I]-tracer for dosimetry purposes followed 10 days later by individualized therapeutic infusions of [131I]tositumomab (median, 19.4 Gbq [525 mCi]; range, 12.1 to 42.7 Gbq [328 to 1,154 mCi]) to deliver 25 to 27 Gy to the critical normal organ receiving the highest radiation dose. ASCT was performed approximately 2 weeks after therapy.


RESULTS
Twenty-four patients with a median age of 64 years (range, 60 to 76 years), who had received a median of four prior regimens (range, two to 14 regimens), were treated. Thirteen patients (54%) had chemotherapy-resistant disease. The estimated 3-year overall and progression-free survival rates were 59% and 51%, respectively, with a median follow-up of 2.9 years (range, 1 to 6 years). All patients experienced expected myeloablation with engraftment of platelets (> or = 20 K/microL) and neutrophils ( 500/microL), occurring at a median of 9 and 15 days after ASCT, respectively. There were no treatment-related deaths, and only two patients experienced grade 4 nonhematologic toxicity.


CONCLUSIONS
Myeloablative RIT and ASCT is a safe and effective therapeutic option for older adults with relapsed B-NHL.
Gopal
Ajay K
AK
Department of Medicine, Division of Medical Oncology, University of Washington, Seattle Cancer Care Alliance, Seattle, WA 98195, USA. agopal@u.washington.edu
Rajendran
Joseph G
JG
Gooley
Ted A
TA
Pagel
John M
JM
Fisher
Darrell R
DR
Petersdorf
Stephen H
SH
Maloney
David G
DG
Eary
Janet F
JF
Appelbaum
Frederick R
FR
Press
Oliver W
OW
D000368:Aged; D000911:Antibodies, Monoclonal / Q000008:administration & dosage / Q000627:therapeutic use*; D018951:Antigens, CD20 / Q000008:administration & dosage / Q000627:therapeutic use*; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D016009:Chi-Square Distribution; D003131:Combined Modality Therapy; D018450:Disease Progression; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D007457:Iodine Radioisotopes / Q000008:administration & dosage / Q000627:therapeutic use*; D016393:Lymphoma, B-Cell / Q000473:pathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D016499:Radioimmunotherapy / Q000379:methods*; D011879:Radiotherapy Dosage; D016019:Survival Analysis; D016896:Treatment Outcome
D000911:Antibodies, Monoclonal; D018951:Antigens, CD20; D000970:Antineoplastic Agents; D007457:Iodine Radioisotopes; C119496:tositumomab I-131