Weight-based dosing of Yttrium 90 ibritumomab tiuxetan in patients with relapsed or refractory B-cell non-Hodgkin lymphoma.

Abstract

BACKGROUND:

Ibritumomab tiuxetan radioimmunotherapy produces durable remissions in patients with relapsed/refractory indolent non-Hodgkin lymphoma. The dosing of Yttrium 90 (90Y)-ibritumomab tiuxetan is based on patient weight and platelet count: 0.4 mCi/kg in patients with a count >or= 150 x 10(9)/L, to a maximum dose of 32 mCi. Patients weighing > 80 kg with platelet counts of >or= 150 x 10(9)/L receive a lower dose per unit of body weight. We evaluated whether this influences the safety or efficacy of treatment.

PATIENTS AND METHODS:

Data on efficacy and safety in patients in 3 registration trials who were treated with 90Y ibritumomab tiuxetan at 0.4 mCi/kg (patients weighing <or= 80 kg) or 32 mCi (patients weighing > 80 kg) were collected.

RESULTS:

Clinical responses were evaluated in 103 patients weighing <or= 80 kg (median, 70 kg) and 67 patients weighing > 80 kg (median, 95 kg). Sex (41% female vs. 73% male) was the only significantly different characteristic between the patients weighing <or= 80 kg and > 80 kg, respectively. The overall response rates were 79% (<or= 80 kg) and 70% (> 80 kg), and the complete response rates were 28% and 34%, respectively. Median times to progression were 8.9 months (<or= 80 kg) and 9.5 months (> 80 kg). There were no significant differences in efficacy measures or in the incidences of grade 3/4 nonhematologic adverse events, neutropenia, thrombocytopenia, or anemia.

CONCLUSION:

The dose of 90Y ibritumomab tiuxetan was < 0.4 mCi/kg in 39% of patients, owing to the 32-mCi dose cap, but the efficacy or safety of 90Y ibritumomab tiuxetan in patients > 80 kg was not affected.

• Authors: Gregory A Wiseman, Peter S Conti, Katie Vo, Russell J Schilder, Leo I Gordon, Christos Emmanouilides, Dan H Silverman, Thomas E Witzig, Mohamed Darif, Arturo Molina
• Journal: Clinical lymphoma & myeloma (Clin Lymphoma Myeloma) Vol. 7 Issue 8 Pg. 514-7 (Sep 2007) ISSN: 1557-9190 [Print] United States
• PMID: 18021468 (Publication Type: Clinical Trial, Phase I, Clinical Trial, Phase II, Clinical Trial, Phase III, Journal Article, Randomized Controlled Trial)

Chemical References

• Antibodies, Monoclonal
• Radiopharmaceuticals
• ibritumomab tiuxetan

Topics

• Adult
• Aged
• Aged, 80 and over
• Antibodies, Monoclonal (administration & dosage, adverse effects)
• Body Weight
• Female
• Humans
• Lymphoma, B-Cell (drug therapy, radiotherapy)
• Male
• Middle Aged
• Platelet Count
• Radioimmunotherapy
• Radiopharmaceuticals (administration & dosage, adverse effects)
• Treatment Outcome