Interim analysis results from the prospective, postapproval REFLECT study indicate the Sandoz rituximab biosimilar treatment was associated with safety and efficacy profiles consistent with those previously described for R-CHOP in untreated patients with diffuse large B-cell lymphoma.
Following the approval of the rituximab biosimilar SDZ-RTX, a prospective study (REFLECT) was initiated to collect real-world evidence of the clinical efficacy and safety of SDZ-RTX in untreated patients with CD20+ diffuse large B-cell lymphoma (DLBCL); the interim results of this study were presented at the 2020 American Society of Clinical Oncology Virtual Scientific Program.
In this postapproval study, eligible adult patients with untreated CD20+ DLBCL received SDZ-RTX as part of the cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) regimen every 2 to 3 weeks for 6 to 8 cycles. The primary end point was investigator-assessed complete response (CR) rate at the end of treatment; CR was defined as the revised Cheson response criteria for malignant lymphoma that excludes complete remission/unconfirmed. Secondary end points included overall response rate (ORR), progression-free survival at 24 months, and adverse events (AEs); assessments were done at baseline and are being done at all scheduled treatment and follow-up visits.
At the data cutoff (September 30, 2019), a total of 170 patients were enrolled in the study. The median age among the study population was 70 years and 52% of patients were female; the majority of patients had an Eastern Cooperative Oncology Group score of 0 or 1. Patients presented with stage I or II disease (55%) and low-to-intermediate disease risk, with an International Prognostic Index of 0 to 2 (50%). Of the enrolled patients, 38% completed the 12-month observation period and 21% of patients discontinued treatment; treatment for 41% of patients was ongoing at the time of the analysis.
At the end of treatment, 57% of patients treated with SDZ-RTX achieved a CR rate of 57%, for an ORR of 88% including partial response rate of 31%. Treatment-emergent AEs of any grade occurred in 83% of patients, and treatment-related AEs were reported in 28% of patients. Serious AEs (SAEs) were experienced by 38% of patients, with treatment-related SAEs occurring in 7% of patients. Deaths that occurred during treatment were reported in 2.4% of patients. The most common AEs included anemia (23%), fatigue (21%), and polyneuropathy (15%). Eight percent of patients discontinued the drug because of AEs.
Based on the results of the interim analysis of the prospective postapproval REFLECT study, the authors concluded that the rituximab biosimilar treatment was associated with safety and efficacy profiles consistent with those previously described for R-CHOP in untreated patients with DLBCL.
Reference
Welslau M, et al. ASCO 2020. Abstract 578.