Tositumomab and iodine-131 tositumomab produces durable complete remissions in a subset of heavily pretreated patients with low-grade and transformed non-Hodgkin's lymphomas.

Abstract

PURPOSE:

This study is an integrated efficacy analysis of the five clinical trials of tositumomab and iodine-131 tositumomab in patients with relapsed or refractory low-grade, follicular, or transformed low-grade non-Hodgkin's lymphoma (NHL) that resulted in the regulatory approval of the iodine-131 tositumomab by the US Food and Drug Administration.

PATIENTS AND METHODS:

This integrated analysis included 250 patients. Patients received a single course of iodine-131 tositumomab. Responses were assessed by an independent panel of radiologists and oncologists.

RESULTS:

Response rates in the five trials ranged from 47% to 68%; complete response rates ranged from 20% to 38%. With a median follow-up of 5.3 years, the 5-year progression-free survival was 17%. Eighty-one (32%) of 250 patients had a time to progression of > or = 1 year (termed durable response population). For the durable response population, 44% had not progressed at > or = 2.5 to > or = 9.5 years and had a median duration of response of 45.8 months. The median duration of complete response was not reached. The durable response population had many poor prognostic characteristics, including bone marrow involvement (41%), bulky disease > or = 5 cm (49%), and transformed histology (23%). Forty-three percent of the patients had been treated with more than four prior therapies and 36% had not responded to their most recent therapy.

CONCLUSION:

The tositumomab and iodine-131 tositumomab therapeutic regimen produces high response rates in patients with relapsed or refractory low-grade, follicular, and transformed low-grade NHL, with a sizable subgroup of patients achieving long-term durable responses.

• Authors: Richard I Fisher, Mark S Kaminski, Richard L Wahl, Susan J Knox, Andrew D Zelenetz, Julie M Vose, John P Leonard, Stewart Kroll, Stanley J Goldsmith, Morton Coleman
• Journal: Journal of clinical oncology : official journal of the American Society of Clinical Oncology (J Clin Oncol) Vol. 23 Issue 30 Pg. 7565-73 (Oct 20 2005) ISSN: 0732-183X [Print] United States
• PMID: 16186600 (Publication Type: Clinical Trial, Clinical Trial, Phase II, Comparative Study, Journal Article, Multicenter Study, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)

Chemical References

• Antibodies, Monoclonal
• Antineoplastic Agents
• Iodine Radioisotopes
• tositumomab I-131

Topics

• Adult
• Aged
• Aged, 80 and over
• Antibodies, Monoclonal (therapeutic use)
• Antineoplastic Agents (therapeutic use)
• Drug Resistance, Neoplasm
• Female
• Humans
• Iodine Radioisotopes (therapeutic use)
• Lymphoma, Follicular (drug therapy, immunology, radiotherapy)
• Lymphoma, Mantle-Cell (drug therapy, immunology, radiotherapy)
• Lymphoma, Non-Hodgkin (drug therapy, immunology, radiotherapy)
• Male
• Middle Aged
• Neoplasm Recurrence, Local (drug therapy, immunology, radiotherapy)
• Radioimmunotherapy
• Remission Induction
• Salvage Therapy
• Survival Rate