Diffuse Large B Cell Lymphoma

Obinutuzumab Vs Rituximab for Advanced DLBCL: A PET-Guided and Randomized Phase 3 Study

Obinutuzumab Vs Rituximab for Advanced DLBCL: A PET-Guided and Randomized Phase 3 Study By LYSA

In the April 29, 2021 obligation to journal Blood, investigators report on the randomized trial comparing obinutuzumab versus rituximab for advanced diffuse large B-cell lymphoma, in the context of a PET/CT guided treatment approach. 

Transplant eligible patients, between the ages of 18 and 60, with untreated, age-adjusted international prognostic index score (aaIPI) of 1 or higher diffuse large B-cell lymphoma, randomized in a one-to-one fashion to either obinutuzumab or rituximab and stratified by aaIPI (1;2-3) and chemotherapy regimen ACVBP or CHOP).  Consolidation treatment depended on response to interim PET/CT scans.  Responders after cycle 2 and 4 (PET2-/PET4-) received immune-chemotherapy.  Responders after only cycle 4 (PET2+/PET4-) received transplantation. The primary objective was an 8% improvement, hazard ratio 0.73, 80% power; alpha risk, 2.5%, one-sided, and 2-year event free survival in the obinutuzumab arm. 

From September 2012, 670 patients were enrolled, obinutuzumab, 336 patients, rituximab, 334 patients.  A total of 383 patients, 57.2%, were aaIPI 2-3, 339 patients, 50.6%, received CHOP. The median follow-up was 38.7 was.  The event free survival at 2 years was similar in both arms, 59.8% versus 56.6%, P = 0.123 with a hazard ratio of 0.88.  The progression free survival at 2 years in the entire patient population was 83.1%, 95% confidence interval, 80% – 8540%. PET2-/PET4-as well as PET2+/PET4-had similar 2-year progression free survival and overall survival, 89.9% versus 83.9% and 94.8% versus 92.8%.  The 2-year progression free survival and overall survival for PET4+ patients were 62% 83.1%.  Grade 3-5 infections were more frequent in the obinutuzumab arm, 21% versus 12%. 

The authors concluded ” obinutuzumab is not superior to rituximab in aaIPI 1 or higher diffuse large B-cell lymphoma transplant eligible patients.”

https://ashpublications.org/Blood/article-abstract/137/17/2307/474212/Obinutuzumab-vs-rituximab-for-advanced-DLBCL-a-PET?redirectedFrom=fulltext

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