Ibritumomab consolidation after 3 cycles of CHOP plus radiotherapy in high-risk limited-stage aggressive B-cell lymphoma: SWOG S0313.

In the S0313 trial, we evaluated the impact of adding ibritumomab tiuxetan consolidation to 3 cycles of standard cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy plus involved field radiotherapy (IFRT) in patients with limited-stage aggressive B-cell non-Hodgkin lymphoma (LD-NHL). Patients with at least 1 stage-modified adverse risk factor (nonbulky stage II, age >60 years, elevated lactate dehydrogenase, or World Health Organization performance status of 2) were treated with CHOP on days 1, 22, and 43, followed 3 weeks later by 40 to 50 Gy of IFRT. An ibritumomab tiuxetan regimen was initiated 3 to 6 weeks following IFRT. Forty-six patients were registered and eligible, with median follow-up of 7.3 years. The progression-free survival estimate is 89% at 2 years, 82% at 5 years, and 75% at 7 years. The overall survival estimate is 91% at 2 years, 87% at 5 years, and 82% at 7 years. Grade 4 adverse events occurring more than once included neutropenia (8), leukopenia (5), and lymphopenia (2). Febrile neutropenia was observed in 4 patients. No cases of treatment-related myeloid neoplasms were noted. In conclusion, patients with high-risk LD-NHL treated with 3 cycles of CHOP plus IFRT followed by ibritumomab tiuxetan consolidation had outcomes that compare favorably to our historical experience. The clinical trial was registered at www.clinicaltrials.gov as #NCT00070018.