Randomized Phase II Trial Comparing Obinutuzumab (GA101) With Rituximab in Patients With Relapsed CD20+ Indolent B-Cell Non-Hodgkin Lymphoma: Final Analysis of the GAUSS Study.

Abstract

PURPOSE:

Obinutuzumab (GA101), a novel glycoengineered type II anti-CD20 monoclonal antibody, demonstrated responses in single-arm studies of patients with relapsed/refractory non-Hodgkin lymphoma. This is the first prospective, randomized study comparing safety and efficacy of obinutuzumab with rituximab in relapsed indolent lymphoma. The primary end point of this study was the overall response rate (ORR) in patients with follicular lymphoma after induction and safety in patients with indolent lymphoma.

PATIENTS AND METHODS:

A total of 175 patients with relapsed CD20(+) indolent lymphoma requiring therapy and with previous response to a rituximab-containing regimen were randomly assigned (1:1) to four once-per-week infusions of either obinutuzumab (1,000 mg) or rituximab (375 mg/m(2)). Patients without evidence of disease progression after induction therapy received obinutuzumab or rituximab maintenance therapy every 2 months for up to 2 years.

RESULTS:

Among patients with follicular lymphoma (n = 149), ORR seemed higher for obinutuzumab than rituximab (44.6% v 33.3%; P = .08). This observation was also demonstrated by a blinded independent review panel that measured a higher ORR for obinutuzumab (44.6% v 26.7%; P = .01). However, this difference did not translate into an improvement in progression-free survival. No new safety signals were observed for obinutuzumab, and the incidence of adverse events was balanced between arms, with the exception of infusion-related reactions and cough, which were higher in the obinutuzumab arm.

CONCLUSION:

Obinutuzumab demonstrated a higher ORR without appreciable differences in safety compared with rituximab. However, the clinical benefit of obinutuzumab in this setting remains unclear and should be evaluated within phase III trials.

• Authors: Laurie H Sehn, Andre Goy, Fritz C Offner, Giovanni Martinelli, M Dolores Caballero, Ole Gadeberg, Tara Baetz, Andrew D Zelenetz, Gianluca Gaidano, Luis E Fayad, Rena Buckstein, Jonathan W Friedberg, Michael Crump, Branimir Jaksic, Pier Luigi Zinzani, Swaminathan Padmanabhan Iyer, Deniz Sahin, Akiko Chai, Günter Fingerle-Rowson, Oliver W Press
• Journal: Journal of clinical oncology : official journal of the American Society of Clinical Oncology (J Clin Oncol) Vol. 33 Issue 30 Pg. 3467-74 (Oct 20 2015) ISSN: 1527-7755 [Electronic] United States
• PMID: 26282650 (Publication Type: Clinical Trial, Phase II, Journal Article, Multicenter Study, Randomized Controlled Trial)
• Copyright: © 2015 by American Society of Clinical Oncology.

Chemical References

• Antibodies, Monoclonal, Humanized
• Antigens, CD20
• Antineoplastic Agents
• Rituximab
• obinutuzumab

Topics

• Adult
• Aged
• Aged, 80 and over
• Antibodies, Monoclonal, Humanized (administration & dosage, adverse effects)
• Antigens, CD20 (biosynthesis)
• Antineoplastic Agents (administration & dosage, adverse effects)
• Disease-Free Survival
• Drug Administration Schedule
• Female
• Humans
• Infusions, Intravenous
• Lymphoma, B-Cell (drug therapy)
• Male
• Middle Aged
• Prospective Studies
• Rituximab (administration & dosage, adverse effects)