Iodine-131 Anti-B1 Antibody Consolidation for Patients With Non-Hodgkin's Lymphoma Following First-line CHOP

Phase II Multicenter Study of Iodine-131 Anti-B1 Antibody Consolidation For Patients With Diffuse Large B-Cell Non-Hodgkin's Lymphoma Following First-line CHOP

This is a multicenter study for the long-term follow-up of surviving patients who are expected to complete or who have completed at least two years of follow-up after treatment with Iodine I 131 Tositumomab (BEXXAR) on studies CP-97-011, CP-98-025, CP-99-032, or CP-99-036. All patients will be assessed for survival and disease status, including subsequent therapy for Diffuse Large B-cell Non-Hodgkin's Lymphoma (NHL), and for long-term safety. Additionally laboratory evaluations consisting of a thyroid stimulating hormone (TSH) level and a complete blood cell (CBC) count with a differential and platelet count will be obtained annually. Additionally, patients who remain in long-term response following Iodine I 131 Tositumomab treatment will be followed for response and progression.

This is a phase II, open-label, multicenter study of Iodine-131 Anti-B1 Antibody consolidation for 20 patients with diffuse large B-cell non-Hodgkin's lymphoma (NHL) achieving a partial response (PR), an unconfirmed complete response (CRu), or complete response (CR) following 6-8 cycles of first-line cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy. Although the majority of patients entered in previous Iodine-131 Anti-B1 Antibody studies had low-grade or transformed low-grade NHL, 15 patients with de novo intermediate-grade NHL have been treated. Patients will undergo two dosing phases of Iodine-131 Anti-B1 Antibody.

In the first phase, termed the "dosimetric dose," patients will receive an infusion of unlabeled Anti-B1 Antibody (450 mg) over 60 minutes followed by a 30-minute infusion (including a 10-minute flush) of Anti-B1 Antibody (35 mg) that contains 5 mCi of Iodine-131. 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 the three imaging time points, a patient-specific dose of Iodine-131 will be calculated to deliver the desired total body dose of radiotherapy. In the second phase, termed the "therapeutic dose," patients will receive a 60-minute infusion of unlabeled Anti-B1 Antibody (450 mg) followed by a 30-minute infusion (including a 10-minute flush) of 35 mg Anti-B1 Antibody labeled with a patient-specific dose of Iodine-131 calculated to deliver a 75 cGy total body radiation dose . Patients who have platelet counts of 100,000-149,999 cells/mm3 will receive 65 cGy and patients who are obese will be dosed based upon 137% of their lean body mass. Patients will be treated with 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 Anti-B1 Antibody (i.e., dosimetric dose) and continuing for 14 days following the last infusion of Iodine-131 Anti-B1 Antibody (i.e., therapeutic dose).

The primary endpoint of this study is to determine the incidence of Grade IV hematologic toxicity following Iodine-131 Anti-B1 Antibody consolidation for patients with diffuse large B-cell NHL who achieved a response (PR, CRu, CR) following first-line CHOP chemotherapy. The secondary efficacy endpoints are to determine the complete response rate, duration of response, duration of complete response, progression-free survival, and time to treatment failure. The pharmacokinetic endpoint is to determine the total body residence time following the dosimetric dose. The secondary safety endpoints are to determine the incidence of adverse experiences, hematologic toxicity (e.g., nadir, time to nadir, and time to recovery), use of supportive care, percent of patients converting to human anti-murine antibody (HAMA) positivity, and survival.

Inclusion Criteria:

• male or female subjects age 18 to 80 years, inclusive, with any International Prognostic Index score; treated with 6 or more cycles of first-line CHOP chemotherapy and achieved a PR, CRu, or CR
• de novo diffuse large B-cell NHL according to the REAL classification; Ann Arbor stage III, stage IV, or bulky stage II disease (any mass ≥10 cm in diameter)
• less than an average of 25% of the intratrabecular marrow space involved by NHL in bilateral bone marrow biopsy specimens or <10% involvement with NHL from unilateral bone marrow biopsy; tumor tissue expressing the CD20 antigen
• ≥60% performance status on the Karnofsky Performance Scale and an anticipated survival of at least 3 months
• absolute neutrophil count (ANC) ≥1500 cells/mm3 and platelet count ≥100,000/mm3
• adequate renal function (serum creatinine <1.5 × upper limit of normal [ULN]) and hepatic function (total bilirubin ≤2.0 × ULN and aspartate aminotransferase <5 × ULN)

Exclusion Criteria:

• prior radiation, prior biological therapy, or prior chemotherapy other than first-line CHOP
• active bilateral obstructive hydronephrosis
• New York Heart Association class III or IV heart disease or other serious illness
• prior malignancy other than lymphoma (except for adequately treated skin cancer, in situ cervical cancer, or other cancer for which they had been disease-free for >5 years)
• human immunodeficiency virus infection
• HAMA positive
• brain or leptomeningeal metastases at any time since diagnosis
• active infection requiring intravenous anti-infectives
• pregnant or breastfeeding