Gallium, rituximab, and dexamethasone for relapsed NHL

Abstract

8079 Background: Almost 50% of patients with intermediate grade non-Hodgkin's lymphomas (NHL) treated with standard CHOP- like therapy will have less than a complete response (CR) after treatment or will relapse after obtaining a CR. Salvage chemotherapy followed in responders by an autologous stem cell transplant (ASCT) can be curative. For many patients, this is not an option due to age, comorbidities, or lack of response. A non-cross resistant agent with activity in NHL which could salvage more patients is gallium nitrate Methods: We conducted a phase II clinical trial investigating the combination 3 non-myelosuppressive agents, gallium nitrate, rituximab and dexamethasone (GaRD) for relapsed or refractory DLBCL, MCL or transformed follicular lymphomas. Gallium is given at 200mg/m2 CIV days 1–7, rituximab 375mg/m2 IVPB day 1 and dexamethasone 40 mg po days 1–4. Eligible patients had relapsed or refractory disease and had a SWOG PS ≤3. Patients may have failed prior ASCT or allogeneic SCT. This was a 2 stage, phase II study with initial evaluation after 22 patients of whom at least 10 responders were needed for completion of the study, as determined prior to start of trial Results: We enrolled 22 patients on study. 15 had large cell, 6 had transformed follicular and 1 had mantle cell NHL. Most of these patients were refractory to one or several prior salvage regimens [13/22 (59%)]; all had prior rituximab 22/22 (100%) and 18/22 (82%) had it with there most recent treatment. No patients developed grade 3 or 4 toxicities, except grade 4 lymphopenia in 7/22 (32%). The overall response rate was 10/22 (45%); CR/CRu 8/22 (36%); PR 2/22 (9%); SD 4/22 (18%); and PD 8/22 (36%). Five patients went on to receive stem cell transplant (including 3 allogeneic and 2 ASCT). Two of the responders were patients who had failed a prior stem cell transplant: 1 ASCT failure who remains in CR >18 months and an allograft failure in CR >14 months after relapse. Of the 22, 10 (46%) are alive at a median f/u of 17.2 months, of whom 7 are currently NED Conclusions: This regimen appears to be effective and relatively non-toxic for patients with relapsed and refractory NHL, including stem cell transplant failure. As CR at ASCT may be associated with an improved outcome, a trial of GaRD combined with RICE is planned to improve cytoreduction prior to ASCT in patients with relapsed NHL. No significant financial relationships to disclose.