Long-term efficacy and safety of CT-P10 or rituximab in untreated advanced follicular lymphoma: a randomized phase 3 study.

Rituximab biosimilars are a cornerstone of treatment of advanced-stage follicular lymphoma (FL). This double-blind, parallel-group, phase 3 trial randomized (1:1) adults (≥18 years) with stage III to IV indolent B-cell lymphoma, including grades 1 to 3a FL, to receive CT-P10 or rituximab (375 mg/m2 IV), with cyclophosphamide, vincristine, and prednisone, every 3 weeks for 8 cycles (induction period). Patients achieving complete response (CR), unconfirmed CR, or partial response (PR) received CT-P10 or rituximab maintenance for 2 years (375 mg/m2, every 8 weeks). Primary end points were previously reported, proving noninferiority of efficacy and pharmacokinetic equivalence of CT-P10 to rituximab. Secondary end points included overall response rate (PR+CR) during the induction period per 2007 International Working Group (IWG) criteria, survival analyses, and overall safety. Between 28 July 2014 and 29 December 2015, 140 patients were randomized (70 per group). Median follow-up was 39.9 months (interquartile range, 36.7-43.5). Per 1999 IWG criteria, 4-year Kaplan-Meier estimates (95% confidence interval [CI]) for CT-P10 and rituximab were 61% (47% to 73%) and 55% (36% to 70%) for progression-free survival (hazard ratio, 1.33 [95% CI, 0.67-2.63]; P=.409), respectively, and 88% (77% to 94%) and 93% (83% to 97%) for overall survival (5.29 [0.84-33.53]; P=.077). Overall, 90% (CT-P10) and 86% (rituximab) of patients experienced treatment-emergent adverse events. Long-term safety profiles were similar between groups. Findings confirm favorable outcomes for CT-P10-treated patients with advanced-stage FL and demonstrate comparable long-term efficacy and overall safety between CT-P10 and rituximab. This trial was registered at www.clinicaltrials.gov as #NCT02162771.