Phase II a Randomized Study of Iodine-131 Anti-b1 Antibody Versus Anti-b1 Antibody in Chemotherapy-relapsed/Refractory Low-grade or Transformed Low-grade Non-Hodgkin's Lymphoma (NHL)
This is a Phase II randomized, controlled, two-arm, open-label, multicenter study comparing
the safety and efficacy of tositumomab and iodine I 131 tositumomab to tositumomab for the
treatment of chemotherapy-relapsed or refractory low-grade or transformed low-grade B-cell
Treatment Arm A: Subject will undergo 2 phases of study. In the first phase, termed
"dosimetric dose", subjects will receive tositumomab (450 mg) followed by tositumomab (35
mg) that has been trace labeled with 5mCi) Iodine-131 tositumomab. Whole body gamma camera
scans will be obtained on day 0, day 2, 3, or 4, and day 6 or 7 following the dosimetric
dose. Using the dosimetric data from three imaging time points, a subject-specific dose of
iodine I 131 tositumomab to deliver the desired total body dose of radiotherapy will be
calculated. In the second phase of the study, termed "therapeutic dose", subjects will
receive unlabeled tositumomab (450mg) followed by iodine tositumomab (35mg) labeled with
the subject-specific dose of iodine I-131 to deliver a whole body dose of 75 cGy to
subjects. Subjects with platelet counts of 100,001 - 149,999 cells/mm3, will receive 65
cGy and subjects who are obese will be doses based on 137% of their lean body mass.
Subjects will be treated with either saturated solution potassium iodide (SSKI), Lugol's
solution, or potassium iodide tablets starting at least 24 hours prior to the first infusion
of the Iodine-131 tositumomab (i.e., the dosimetric dose) and continuing for 14 days
following the last infusion of radiolabeled tositumomab (i.e., the therapeutic dose).
Treatment Arm B: Subjects will receive the same amount of unlabeled tositumomab (450 + 35
mg) administered over the same time-frame as Arm A on the study Days 0 and 7 (the day 7 dose
may be delayed but no longer than 14 days after the first dose).
Crossover treatment Arm B: Subjects in Arm B may crossover and receive Iodine-131
tositumomab following progression of their lymphoma if they still fulfill the protocol
inclusion exclusion criteria (except exclusion criteria#12) and are HAMA-negative.
Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Crossover Assignment, Masking: Open Label, Primary Purpose: Treatment
Number of Participants (Par.) With Confirmed Response as Assessed by the Investigator
Responses had to be confirmed by 2 separate evaluations occurring >=4 weeks apart. Par. with confirmed response include those with Complete Response (CR: complete resolution of all disease-related radiological abnormalities and the disappearance of all signs and symptoms related to the disease), Clinical Complete Response (CCR: complete resolution of all disease-related symptoms; residual foci, thought to be residual scar tissue, are present), or Partial Response (PR: >=50% reduction in the sum of the products of the longest perpendicular diameters of all measurable lesions; no new lesions).
Participants were evaluated for up to two years in Study BEX104515 and for up to 11.9 years in Study BEX104526.
GSK Clinical Trials
United States: Food and Drug Administration