131I-tositumomab therapy as initial treatment for follicular lymphoma.
BACKGROUND
Advanced-stage follicular B-cell lymphoma is considered incurable. Anti-CD20 radioimmunotherapy is effective in patients who have had a relapse after chemotherapy or who have refractory follicular lymphoma, but it has not been tested in previously untreated patients.


METHODS
Seventy-six patients with stage III or IV follicular lymphoma received as initial therapy a single course of treatment with 131I-tositumomab therapy (registered as Tositumomab and Iodine I 131 Tositumomab [the Bexxar therapeutic regimen]). This consisted of a dosimetric dose of tositumomab and 131I-labeled tositumomab followed one week later by a therapeutic dose, delivering 75 cGy of radiation to the total body.


RESULTS
Ninety-five percent of the patients had any response, and 75 percent had a complete response. The use of polymerase chain reaction (PCR) to detect rearrangement of the BCL2 gene showed molecular responses in 80 percent of assessable patients who had a clinical complete response. After a median follow-up of 5.1 years, the actuarial 5-year progression-free survival for all patients was 59 percent, with a median progression-free survival of 6.1 years. The annualized rate of relapse progressively decreased over time: 25 percent, 13 percent, and 12 percent during the first, second, and third years, respectively, and 4.4 percent per year after three years. Of 57 patients who had a complete response, 40 remained in remission for 4.3 to 7.7 years. Hematologic toxicity was moderate, with no patient requiring transfusions or hematopoietic growth factors. No cases of myelodysplastic syndrome have been observed.


CONCLUSIONS
A single one-week course of 131I-tositumomab therapy as initial treatment can induce prolonged clinical and molecular remissions in patients with advanced follicular lymphoma.
Kaminski
Mark S
MS
Department of Internal Medicine, Division of Hematology and Oncology, University of Michigan Medical Center, Ann Arbor, MI 48109-0936, USA. mkaminsk@umich.edu
Tuck
Melissa
M
Estes
Judith
J
Kolstad
Arne
A
Ross
Charles W
CW
Zasadny
Kenneth
K
Regan
Denise
D
Kison
Paul
P
Fisher
Susan
S
Kroll
Stewart
S
Wahl
Richard L
RL
D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal / Q000009:adverse effects / Q000627:therapeutic use*; D018951:Antigens, CD20 / Q000276:immunology*; D001402:B-Lymphocytes; D001856:Bone Marrow Examination; D018572:Disease-Free Survival; D005260:Female; D015321:Gene Rearrangement / Q000187:drug effects; D019254:Genes, bcl-2; D006801:Humans; D007958:Leukocyte Count; D008224:Lymphoma, Follicular / Q000235:genetics / Q000276:immunology / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D016499:Radioimmunotherapy / Q000009:adverse effects; D011874:Radiometry; D012074:Remission Induction; D016019:Survival Analysis; D013972:Thyrotropin / Q000097:blood
D000911:Antibodies, Monoclonal; D018951:Antigens, CD20; D013972:Thyrotropin; C119496:tositumomab I-131