Efficacy and Safety of CT-P10 Versus Rituximab in Untreated Low-Tumor-Burden Follicular Lymphoma: Final Results of a Randomized Phase III Study

We assessed the efficacy and safety of rituximab and its biosimilar, CT-P10, in treatment-naive low-tumor-burden follicular lymphoma patients, with a median follow-up of 29.2 months. Data from the trial show that the efficacy and safety of rituximab and CT-P10 were similar, including after a single switch from rituximab to CT-P10. These data support the therapeutic similarity of rituximab and CT-P10. Introduction: This double-blind, parallel-group, active-controlled phase III trial (NCT02260804) assessed CT-P10 and rituximab safety and efficacy in patients with previously untreated low-tumor-burden follicular lymphoma (LTBFL), including after a single switch from rituximab to CT-P10. Patients and Methods: LTBFL patients were randomized (1:1) to receive CT-P10 or rituximab (375 mg/m(2) intravenously; day 1 of 4 7-day cycles). Patients achieving disease control entered a 2-year maintenance period. CT-P10 or rituximab were administered every 8 weeks (6 cycles) in year 1; all patients could receive CT-P10 (every 8 weeks; 6 cycles) in year 2. Secondary endpoints (reported here) were overall response rate (ORR) dur ing the study period, progression-free survival (PFS), time to progression (TTP), and overall survival (OS). Safety and immunogenicity were evaluated. Results: Between November 9, 2015 and January 4, 2018, 258 patients were randomized (130 for CT-P10; 128 for rituximab). ORR was similar between groups over the study period (CT-P10: 88%; rituximab: 87%). After 29.2 months' median follow-up, median PFS, TTP, and OS were not estimable; 24-month Kaplan-Meier estimates suggested similarity between groups. Overall, 114 (CT-P10: 88%), and 104 (rituximab: 81%) patients experienced treatment-emergent adverse events. The single switch was well tolerated. Conclusion: These updated data support therapeutic similarity of CT-P10 and rituximab and support the use of CT-P10 monotherapy for previously untreated LTBFL. (C) 2021 The Authors. Published by Elsevier Inc.