A Retrospective Analysis on the Efficacy and Saftey of Obinutuzumab in the Treatment of Non-Hodgkin B Cell Lymphoma

Backgroud: Obinutuzumab was approved by China’s Drug Administration in June 2021, and there have been few real-world reports about efficacy and safety.

Objective: Analysis the efficacy and safety of Obinutuzumab in the treatment of non-Hodgkin B cell lymphoma in our center.

Methods：We analysed the non-Hodgkin B cell lymphoma patients who received Obinutuzumab combined with chemotherapy or maintenance treatment during September 2021 and July 2023, median follow up 9 months（1-20）, to evaluate efficacy and safety.

Results: In all 165 patients, male 88（53%), female 77（47%）, median 56 (26-83) years. FL 80 (48%), MZL 22 (13%), CLL/SLL 13 (8%), DLBCL 42 (25%), others 8 (5%). Newly diagnosed patients 114 (69%), relapsed/refractory 51 (31%). 124 patients received Obinutuzumab combined therapy, and 42 (25%) patients received Obinutuzumab maintenance treatment. Median treatment 4 cycles（1-11）. I/II 33 (20 %), III/IV 131 (79 %). Low-medium group 91（55%）, medium-high group 74（45%）. ORR 66.7%, CRR 40.6%. 3 patients died of progression of disease. 1 elder patient died of pneumonia. Further subgroup analysis revealed, ORR（78% vs 22%, p<0.001）and CRR（81% vs 19%, p=0.02）of newly diagnosed patients were better than relapsed/refractory patients. There was no difference in CRR among different stages patients（I/II vs III/IV, 24% vs 76%, p=0.424）, ORR（58% vs 42%, p=0.373）and CRR (63% vs 37%, p=0.481）between low-medium and medium-high patients. The patients received more than 4 cycles treatment with better ORR and CRR. The intensive treatment of Obinutuzumab in first cycle could improve ORR (87% vs 13%, p=0.036,）and decreased IgM ( p=0.0016）, but didn’t not affect CRR （87% vs13%, p=0.343）, IgG ( p=0.13） and IgA ( p=0.41）. Maintenance treatment decreased IgM ( p=0.00064）but not for IgG or IgA. In treatment related side effects, any adverse events were 42（25%）, more than grade III were 18（11%）, tumor lysis syndrome 11 (7%), only one patient need blood purification treatment and recovered. Liver injury 8 (5%) . All the infusion-related response 23（14%）were grade I-II. Only 2 patients delayed treatment because of the side effects.

Conclusion: Obinutuzumab is safe and effective in the treatment of non-Hodgkin B cell lymphoma, even for the III/IV or medium-high group patients will have similar results with I/II or low-medium patients. Further follow-up is still needed to determine the long-time efficacy and safety.

Key words: retrospective analysis, Obinutuzumab, non-Hodgkin lymphoma.