Multicenter Phase II Trial of ⁹⁰Y-Ibritumomab Tiuxetan with High-Dose Chemotherapy (Busulfan/Cyclophosphamide/Etoposide) Followed by Autologous Stem Cell Transplantation in Relapsed, Refractoried, or High-Risk B-Cell NHL.

The need of new effective regimen for high-dose chemotherapy followed by autologous stem cell transplantation (ASCT) in aggressive B-cell non-Hodgkin’s lymphoma (NHL) patients and promising results observed so far in trials with ⁹⁰Y-Ibritumomab tiuxetan containing regimens in ASCT strongly warrants the investigation of ⁹⁰Y-Ibritumomab tiuxetan combined busulfan/cyclophosphamide/etoposide (Z-BuCyE) high-dose chemotherapy with ASCT for relapsed, refractoried, or high-risk B-cell NHL. We evaluated efficacy and safety of the combination of Z-BuCyE and ASCT in patients with relapsed, refractoried, or high-risk B-cell NHL. Treatment consisted of two doses of Rituximab (250 mg/m2, IV, day -21, -14) and a single dose of ⁹⁰Y-Ibritumomab (0.4 mCi/kg, IV, day -14). All patients received conditioning regimen: busulfan (3.2 mg/kg, IV, day -7, -6, -5), etoposide (200 mg/m2, IV, day -5, -4), and cytoxan (50 mg/kg, IV, day -3, -2) followed by ASCT (day 0). Thirteen patients were entered the trial. The median age was 46.1 years (range: 25–60), and 6 (46%) patients were male. Histology was diffuse large B-cell (n=10), follicular (n=1), Burkitt (n=1), and mantle cell lymphoma (n=1). The objective overall response rate (ORR) was 76.9% (10/13): continued CR, 38.5% (5/13); induced CR, 23.1% (3/13); continued or induced PR, 15.4% (2/13). Three patients (23.1%) had a PD after transplantation and two of these patients died of progression. Median follow-up duration was 6.0 months. Median progression-free survival (PFS) and median overall survival (OS) has not yet been reached. Toxicity was principally non-hematologic. Grade 2 toxicity included mucositis (53.8%), nausea (61.5%), vomiting (15.4%), diarrhea (23.1%), and elevation of liver enzyme (7.7%). Grade 3 toxicity included mucositis (15.4%), nausea (23.1%), and diarrhea (23.1%). There was no grade 4 toxicity. Infection occurred in ten patients, bleeding in one patient, and there was no treatment related mortality. This preliminary analysis shows that the combination of Z-BuCyE and ASCT has excellent efficacy and is well-tolerated treatments for relapsed, refractoried or high-risk B-cell NHL. This study will be continued till 20 patients enrollment.