Obinutuzumab Plus Bendamustine Prolongs PFS in Rituximab-Refractory Non-Hodgkin Lymphoma
Previous findings showed that patients obinutuzumab plus bendamustine prolonged progression-free survival, but data was immature at the time of analysis.
Obinutuzumab plus bendamustine (G-B) significantly prolongs progression-free survival (PFS) among patients with indolent non-Hodgkin lymphoma (iNHL) compared with bendamustine alone, according to a study published in the Journal of Clinical Oncology.1
For the phase 3 GADOLIN study (ClinicalTrials.gov Identifier: NCT01059630), researchers randomly assigned 413 patients with rituximab-refractory iNHL — of whom 335 had follicular lymphoma (FL) — to undergo induction therapy with obinutuzumab 1000 mg plus bendamustine 90 mg/m2/day or bendamustine 120 mg/m2/day alone; patients who did not experience disease progression in the G-B arm received obinutuzumab 1000 mg maintenance therapy every 2 months. Patients in the G-B arm had a significantly reduced risk of progression of death but did not reach PFS at the time of the primary analysis and data was immature for other clinical endpoints.
The median follow-up for the current analysis was 31.8 months, approximately 11 months longer compared with the former report.
Patients in the G-B arm had a median PFS of 25.8 months compared with 14.1 months among patients in the bendamustine alone arm (hazard ratio [HR], 0.57; 95% CI, 0.44-0.73; P < .001) and overall survival (OS) was improved in the G-B arm as well (HR, 0.67; 95% CI, 0.47-0.96; P = .027). Patients with FL experienced a similar benefit for PFS and OS.
Time to new antilymphoma treatment (TTNT) in the G-B arm (41 months) was more than double the time in the bendamustine alone arm (19 months).
Grade 3 to 5 adverse events (AEs) were reported by 72.5% (148) of patients in the G-B arm and 65.5% (133) of patients in the bendamustine alone group; the most frequently reported AEs included neutropenia, thrombocytopenia, anemia, and infusion-related reactions. Serious AEs occurred in 43.6% (89) compared with 36.9% (75) of patients in the G-B arm and bendamustine alone arm, respectively, and 7.8% (16) and 6.4% (13) of patients died due to fatal AEs, respectively.
The updated results confirm the earlier findings from the GADOLIN study. The authors concluded that “because G-B prolonged OS, PFS, and TTNT compared with [bendamustine] monotherapy in rituximab-refractory FL, this supports the conclusion that G-B is the preferred option in the treatment of these patients.”
- Cheson BD, Chua N, Mayer J, et al. Overall survival benefit in patients with rituximab-refractory indolent non-Hodgkin lymphoma who received obinutuzumab plus bendamustine induction and obinutuzumab maintenance in the GADOLIN study [published online March 27, 2018]. J Clin Oncol. doi: 10.1200/JCO.2017.76.3656