A recent study compared the treatment effects and adverse events of first-line chemotherapy regimens in patients with treatment-naïve diffuse large B-cell lymphoma (DLBCL).
Rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) chemotherapy regimen is considered the standard of care in previously untreated DLBCL. Despite clinical benefit that R-CHOP often provides in this patient population, 20% to 40% of patients experience relapse or recurrence after R-CHOP and have poor outcomes with salvage therapy.
Researchers led by Umberto Vitolo, MD, oncology and hematology specialist, San Giovanni Battista Hospital (Italy), conducted a phase III trial to compare obinutuzumab (G) plus CHOP (G-CHOP) with R-CHOP in patients with treatment-naïve advanced-stage DLBCL. A total of 1418 patients were randomly assigned to receive either eight 21-day cycles of G (n = 706 patients) or R (n = 712 patients), plus six or eight cycles of CHOP. Primary outcome of the study was investigator-assessed progression-free survival (PFS).
Results of the study were published in the Journal of Clinical Oncology (online August 10, 2017; doi:10.1200/JCO.2017.73.3402).
Researchers reported that after a median of 29 months, the total investigator-assessed PFS events were similar between patients in the G-CHOP (n = 201; 28.5%) and R-CHOP (n = 215; 30.2%) cohorts (HR, 0.92; 95% CI, 0.76-1.11; P = .3868). Estimated 3-year PFS rates were 70% and 67%, respectively.
Additionally, secondary endpoints (ie, independently reviewed PFS, other time-to-event end points, and tumor response rates) were comparable between the G-CHOP and R-CHOP cohorts. In exploratory subgroup analyses, researchers reported that patients with germinal-center B-cell subtype had a better PFS than patients with activated B-cell subtype, regardless of treatment.
Patient-reported grade 3-5 and serious adverse events were reported at a higher frequency in the G-CHOP cohort than the R-CHOP cohort. The most frequently reported adverse events included neutropenia, infusion-related reactions, nausea, and constipation.
Researchers concluded that, “G-CHOP did not improve PFS compared with R-CHOP in patients with previously untreated DLBCL.” R-CHOP should remain the standard of care in this disease setting, they wrote, and biomarker analysis may help define a future role for obinutuzumab in DLBCL.—Zachary Bessette
