Phase 2 study of CHOP-R-14 followed by ⁹⁰Y-ibritumomab tiuxetan in patients with previously untreated diffuse large B-cell lymphoma

The aim of this open-label, single-center, phase 2 study was to assess the efficacy and safety of dose-dense CHOP-R-14 followed by ⁹⁰Y-ibritumomab radioimmunotherapy (RIT) in patients with previously untreated diffuse large B-cell lymphoma (DLBCL). A total of 20 patients, the majority presenting with high-risk characteristics, were enrolled to receive dose-dense cyclophosphamide, doxorubicin, vincristine, prednisone and rituximab every 14 days (CHOP-R-14), followed by ⁹⁰Y-ibritumomab tiuxetan consolidation. Sixteen patients completed RIT consolidation (rituximab 250 mg/m² on day 1 and day 7, 8, or 9, followed by a single injection of ⁹⁰Y-ibritumomab). Complete response (CR) rates of 75 and 95% were observed after treatment with CHOP-R-14 and RIT, respectively; 4 of the 5 patients who achieved a partial response after CHOP-R-14 converted to CR following treatment with RIT. With a median follow-up of 89.7 months, the progression-free and overall survival rates for the cohort were 75 and 85%, respectively. Hematological adverse events were common following CHOP-R-14 and RIT, but they were manageable with treatment interruption. Therefore, this regimen achieved promising survival outcomes in high-risk DLBCL on long term follow-up, with manageable toxicity.