Phase III study of obinutuzumab in Japanese patients with previously untreated FL

On 19 July 2018, a paper was published in the International Journal of Hematology by Ken Ohmachi, School of Medicine, Tokai University, Kanagawa, Japan, and colleagues on a sub-analysis of the GALLIUM phase III study (NCT01332968). This sub-analysis assessed the efficacy and safety of obinutuzumab in Japanese patients with previously untreated follicular lymphoma (FL).

The GALLIUM phase III study assessed the use of obinutuzumab plus chemotherapy (G-chemo) compared with rituximab plus chemotherapy (R-chemo) in previously untreated FL.

Study Overview

• N = 123 patients included in the Japanese sub-group; n = 65 received G-chemo; n = 58 received R-chemo
  • Patient characteristics of G-chemo: 33.8% = male; median age = 61 (range, 42–77)
  • Patient characteristics of R-chemo: 41.4% = male; median age = 61.5 (range, 39–85)
• Primary endpoint: Investigator-assessed progression-free survival (INV-PFS)
• Secondary endpoints included; Overall response rate (ORR), complete response (CR) at the end of study (EOI), overall survival (OS), event-free survival (EFS), disease-free survival (DFS), duration of response (DOR), time to new anti-lymphoma treatment (TTNALT) and safety

Key Findings

• 3-year PFS for G-chemo vs R-chemo:
  • 9% (95% CI, 78.7–95.3) vs 74.7% (95% CI, 57.6–85.8)
    • HR 0.42 (95% CI, 0.15–1.15), P = 0.08
  • 3-year OS = 96.9% (G-chemo) vs2% (R-chemo)
  • ORR = 92.3% (G-chemo) vs4% (R-chemo); (95% CI, 0.93 (− 9.7, 11.6); P = 0.75)
    • CR = 35.4% (G-chemo) vs5% (R-chemo); (95% CI, 0.90 (− 17.0, 18.8); P = 0.94)
  • EFS and TTNALT = improvement was seen in G-chemo vs R-chemo
  • Most frequent adverse events (AEs) grade ≥3 for G-chemo vs R-chemo
    • Neutropenia = 90.8% vs 3%
    • Leukopenia = 21.5% vs1%
    • Febrile neutropenia = 20% vs3%

The authors concluded that the results from the analysis of the Japanese sub-group on the GALLIUM study were consistent with the results from the global population. This demonstrated ‘clinically meaningful improvements in PFS in first-line FL patients treated with G-chemo vs R-chemo’. Additionally, the authors noted that there were high rates of neutropenia seen in Japanese patients and commented that these may ‘reflect the extensive use of CHOP chemotherapy in Japan.’