Obinutuzumab and bendamustine in iNHL: Updated analysis of the GADOLIN study

On 27 March 2018, an updated analysis was published in the Journal of Clinical Oncology on the randomized phase III GADOLIN study (NCT01059630) by Bruce Cheson, Deputy Chief Division of Hematology and Oncology at the Georgetown University Medical Center, Washington D.C., and colleagues.

The open-label, randomized, phase III study assessed the use of obinutuzumab (GA101; G) and bendamustine (B) in patients with rituximab-refractory indolent non-Hodgkin lymphoma (iNHL). The primary endpoint of the study was progression-free survival (PFS) assessed by an independent review committee (IRC). Secondary endpoints were investigator-assessed PFS, overall survival (OS), time to new treatment (TTNT) and safety.

Patients included in the study were diagnosed with rituximab-refractory CD20 positive iNHL. Patients received treatment with either G and B or B-monotherapy. Patients who did not progress after this treatment received G maintenance for up to 2 years.

Key Findings

• Total number of patients included in the study, N = 413
• iNHL subtypes included; follicular lymphoma (FL) n = 335, marginal zone lymphoma (MZL) n = 47, small lymphocytic lymphoma (SLL) n = 30 and Waldenström macroglobulinemia (WM) n = 1
  • In the intention-to-treat (ITT) population:
    • n = 204 received G-B and n = 209 received B-monotherapy
  • In the FL patient population:
    • n = 164 received G-B and n = 171 received B-monotherapy
  • Median follow-up = 31.8 months
  • IRC-assessed median PFS = 25.8 months G-B vs 1 months B-monotherapy (HR, 0.57; 95% CI, 0.44–0.73; P < 0.001)
  • OS was prolonged in patients receiving G-B vs B-monotherapy (HR 0.67; 95% CI, 0.47–0.96; P = 0.027)
  • Common adverse events (AEs) grade ≥3 G-B vs B-monotherapy:
    • Neutropenia = 34.8% vs1%
    • Thrombocytopenia = 10.8% vs8%
    • Anemia = 7.4% vs 8%
    • Infusion-related reactions = 9.3% vs 4%

The authors found that PFS was prolonged in patients treated with G-B compared with B-monotherapy. This analysis was able to confirm the efficacy results from the initial analysis and the authors noted that these results were reflected across the subtypes of iNHL. There was also survival benefit observed in rituximab-refractory iNHL patients treated with G-B. No new safety signals emerged.