Follow-up of relapsed B-cell lymphoma patients treated with iodine-131-labeled anti-CD20 antibody and autologous stem-cell rescue.
OBJECTIVE
Radioimmunotherapy (RIT) is a promising treatment approach for B-cell lymphomas. This is our first opportunity to report long-term follow-up data and late toxicities in 29 patients treated with myeloablative doses of iodine-131-anti-CD20 antibody (anti-B1) and autologous stem-cell rescue.


METHODS
Trace-labeled biodistribution studies first determined the ability to deliver higher absorbed radiation doses to tumor sites than to lung, liver, or kidney at varying amounts of anti-B1 protein (0.35, 1.7, or 7 mg/kg). Twenty-nine patients received therapeutic infusions of single-agent (131)I-anti-B1, given at the protein dose found optimal in the biodistribution study, labeled with amounts of (131)I (280 to 785 mCi [10.4 to 29.0 GBq]) calculated to deliver specific absorbed radiation doses to the normal organs, followed by autologous stem-cell support.


RESULTS
Major responses occurred in 25 patients (86%), with 23 complete responses (CRs; 79%). The nonhematopoietic dose-limiting toxicity was reversible cardiopulmonary insufficiency, which occurred in two patients at RIT doses that delivered > or = 27 Gy to the lungs. With a median follow-up time of 42 months, the estimated overall and progression-free survival rates are 68% and 42%, respectively. Currently, 14 of 29 patients remain in unmaintained remissions that range from 27+ to 87+ months after RIT. Late toxicities have been uncommon except for elevated thyroid-stimulating hormone (TSH) levels found in approximately 60% of the subjects. Two patients developed second malignancies, but none have developed myelodysplasia (MDS).


CONCLUSIONS
Myeloablative (131)I-anti-B1 RIT is relatively well tolerated when given with autologous stem-cell support and often results in prolonged remission durations with few late toxicities.
Department of Medicine, University of Washington, Fred Hutchinson Cancer Research Center, Seattle, USA.
S Y
SY
Liu
J F
JF
Eary
S H
SH
Petersdorf
P J
PJ
Martin
D G
DG
Maloney
F R
FR
Appelbaum
D C
DC
Matthews
S A
SA
Bush
L D
LD
Durack
D R
DR
Fisher
T A
TA
Gooley
I D
ID
Bernstein
O W
OW
Press
D000328:Adult; D000911:Antibodies, Monoclonal / Q000009:adverse effects / Q000627:therapeutic use*; D018951:Antigens, CD20 / Q000276:immunology*; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D007457:Iodine Radioisotopes / Q000009:adverse effects / Q000627:therapeutic use*; D016393:Lymphoma, B-Cell / Q000276:immunology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D016499:Radioimmunotherapy / Q000009:adverse effects; D011879:Radiotherapy Dosage; D012008:Recurrence; D012074:Remission Induction
D000911:Antibodies, Monoclonal; D018951:Antigens, CD20; D007457:Iodine Radioisotopes; C119496:tositumomab I-131