Hiddemann W, et al. - In a previous study, obinutuzumab (GA101; G) significantly prolonged progression-free survival (PFS) in previously untreated patients with follicular lymphoma vs rituximab (R) when combined with cyclophosphamide (C), doxorubicin, vincristine (V), and prednisone (P; CHOP); CVP; or bendamustine, so authors assessed the effect of chemotherapy backbone on effectiveness and safety in these patients. For all three chemotherapy backbones, they observed an improved PFS for G plus chemotherapy. Safety profiles seem to differ, though nonrandom chemotherapy allocation may confound comparisons.

Methods

• Researchers randomly assigned 1,202 patients with previously untreated follicular lymphoma (grades 1 to 3a), advanced disease (stage III or IV, or stage II with tumor diameter ≥ 7 cm), Eastern Cooperative Oncology Group performance status 0 to 2, and requiring treatment at a 1:1 ratio to G 1,000 mg on days 1, 8, and 15 of cycle 1 and day 1 of subsequent cycles or R 375 mg/m² on day 1 of each cycle, for six to eight cycles, depending on chemotherapy (allocated nonrandomly by center).
• For 2 years or until disease progression, the responding patients were administered G or R.

Results

• As per data, baseline Follicular Lymphoma International Prognostic Index risk, bulky disease, and comorbidities differed by chemotherapy.
• Findings suggested that, after 41.1 months median follow-up, PFS (primary end point) was superior for G plus chemotherapy (overall hazard ratio [HR], 0.68; 95% CI, 0.54 to 0.87; P=.0016), with consistent results across chemotherapy backbones (bendamustine: HR, 0.63; 95% CI, 0.46 to 0.88; CHOP: HR, 0.72; 95% CI, 0.48 to 1.10; CVP: HR, 0.79; 95% CI, 0.42 to 1.47).
• Results demonstrated the grade 3 to 5 adverse events, notably cytopenias, to be most frequent with CHOP.
• Experts noted that with bendamustine, which was associated with marked and prolonged reductions in T-cell counts, grade 3 to 5 infections and second neoplasms were most frequent.
• In patients treated with bendamustine, fatal events were more frequent, possibly reflecting differences in patient risk profiles.