VcR-CVAD Induction Chemotherapy Followed by Maintenance Rituximab Produces Durable Remissions in Mantle Cell Lymphoma: A Wisconsin Oncology Network Study.

INTRODUCTION: VcR-CVAD was developed as an intermediate-intensity induction regimen with maintenance rituximab (MR) to improve remission durations after first-line therapy for mantle cell lymphoma (MCL) in older and younger patients with MCL. PATIENTS AND METHODS: Patients with previously untreated MCL received VcR-CVAD induction chemotherapy for 6 cycles (21-day cycles). Patients achieving at least a partial response received rituximab consolidation (375 mg/m2 × 4 weekly doses) and MR (375 mg/m2 every 12 weeks × 20 doses). The primary endpoints were overall and complete response (CR), and the secondary endpoints were progression-free survival (PFS) and overall survival (OS). Thirty patients were enrolled, with a median age of 61 years. There was an even distribution of patients < 60 years and ≥ 60 years. Mantle cell lymphoma international prognostic index medium- or high-risk disease was present in 60%. The overall response rate observed was 90% (77% CR/unconfirmed CR). After a median follow-up of 7.8 years, the 6-year PFS and OS were 53% and 70%, respectively. There was no difference in 6-year PFS or OS between the younger (age < 60 years) and older (age ≥ 60 years) subgroups. In a univariate analysis, lactate dehydrogenase, when analyzed for interaction with age, had a significant effect on PFS outcomes at 6 years. There were no pretreatment variables determined to have a significant effect on OS outcomes at 6 years. CONCLUSIONS: Long-term outcomes with VcR-CVAD are comparable with more intensive inductions and consolidation approaches. MCL is biologically heterogeneous, and durable remission can be achieved with intermediate intensity therapy. MR appears to contribute to these excellent outcomes.

Maintenance rituximab following induction chemo-immunotherapy for mantle cell lymphoma: long-term follow-up of a pilot study from the Wisconsin Oncology Network.

Mantle cell lymphoma (MCL) is challenging to manage, with a median survival of 3-5 years. While intensive strategies are often appropriate for younger patients, these approaches are often not appropriate for older patients. In 2006, we reported our initial results using modified R-hyperCVAD (rituximab with hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone) with maintenance rituximab. The complete response rate was 64%, and median progression-free survival (PFS) 37 months. Herein, we update our results, now with a median follow-up of 62 months. The median PFS is unchanged and the median overall survival (OS) is 70 months. The proportion of patients surviving at 5 years is 62%, comparable to studies using intensive strategies in similar patient populations. No late toxicities were noted in our cohort. These long-term results suggest that the modified R-hyperCVAD regimen with maintenance rituximab is an excellent option for older patients with newly diagnosed mantle cell lymphoma.

VcR-CVAD induction chemotherapy followed by maintenance rituximab in mantle cell lymphoma: a Wisconsin Oncology Network study.

Intensive chemotherapy regimens are not feasible in many adults with mantle cell lymphoma (MCL). We sought to build upon our previous experience with a non-intensive regimen, modified R-hyperCVAD chemotherapy (rituximab, cyclophosphamide, vincristine, doxorubicin, dexamethasone) with maintenance rituximab (MR), by the incorporation of bortezomib (VcR-CVAD) and the extension of MR beyond 2 years. Patients with previously untreated MCL received VcR-CVAD chemotherapy every 21 d for six cycles. Patients achieving at least a partial response to induction chemotherapy received rituximab consolidation (375 mg/m(2) × 4 weekly doses) and MR (375 mg/m(2) every 12 weeks × 20 doses). The primary end points were overall and complete response (CR), and secondary endpoints were progression-free (PFS) and overall survival (OS). Thirty patients were enrolled, with a median age of 61 years. All patients had advanced stage disease, and 60% had medium/high MCL International Prognostic Index risk factors. A CR or unconfirmed CR was achieved in 77% of patients. After a median follow-up of 42 months, the 3-year PFS and OS were 63% and 86%, respectively. The observed 3-year PFS and OS with VcR-CVAD in MCL were comparable to reported outcomes with more intensive regimens. A cooperative group trial (E1405) is attempting to replicate these promising results.

Rituximab and CHOP chemotherapy plus GM-CSF for previously untreated diffuse large B-cell lymphoma in the elderly: a Wisconsin oncology network study.

PURPOSE: Human recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF) may potentiate rituximab activity by upregulating CD20 expression and activating effector cells necessary for antibody-dependent cellular cytotoxicity. GM-CSF was combined with standard rituximab + CHOP (cyclophosphamide/doxorubicin/vincristine/prednisone) chemotherapy (R-CHOP) in the treatment of elderly patients with de novo diffuse large B-cell lymphoma (DLBCL). PATIENTS AND METHODS: Thirty-eight patients over the age of 60 years with newly diagnosed DLBCL were treated with R-CHOP every 21 days for 6-8 cycles and GM-CSF 250 µg/m2 per day on days 3-10. Patients were evaluated for response after cycles 4, 6, and 8. The primary endpoint was the rate of complete response, and secondary endpoints were progression-free survival (PFS), event-free survival, and overall survival (OS). RESULTS: Thirty-eight patients were enrolled, with a median age of 72 years, and 29% of patients having high-risk disease (International Prognostic Index [IPI] score ≥ 4). A complete or unconfirmed complete response (CR) was achieved in 53% of patients. After a median follow-up of 51.1 months, the 3-year PFS and OS were 78% and 84%. Twenty-one percent of patients discontinued protocol treatment because of chemotherapy-related toxicity and 16% because of GM-CSF toxicity. Dose intensity for planned chemotherapy cycles was 81.1%. CONCLUSION: These data suggest that survival outcomes may be modestly improved when GM-CSF is combined with R-CHOP in the treatment of elderly DLBCL. GM-CSF had toxicity precluding planned administration in 16% of patients, which may limit usefulness of this agent. Further investigation of GM-CSF in combination with rituximab-containing chemotherapy is warranted.

Bortezomib-resistant nuclear factor-kappaB activity in multiple myeloma cells.

Bortezomib (Velcade/PS341), a proteasome inhibitor used in the treatment of multiple myeloma (MM), can inhibit activation of nuclear factor-kappaB (NF-kappaB), a family of transcription factors often deregulated and constitutively activated in primary MM cells. NF-kappaB can be activated via several distinct mechanisms, including the proteasome inhibitor-resistant (PIR) pathway. It remains unknown what fraction of primary MM cells harbor constitutive NF-kappaB activity maintained by proteasome-dependent mechanisms. Here, we report an unexpected finding that constitutive NF-kappaB activity in 10 of 14 primary MM samples analyzed is refractory to inhibition by bortezomib. Moreover, when MM cells were cocultured with MM patient-derived bone marrow stromal cells (BMSC), microenvironment components critical for MM growth and survival, further increases in NF-kappaB activity were observed that were also refractory to bortezomib. Similarly, MM-BMSCs caused PIR NF-kappaB activation in the RPMI8226 MM cell line, leading to increased NF-kappaB-dependent transcription and resistance to bortezomib-induced apoptosis. Our findings show that primary MM cells frequently harbor PIR NF-kappaB activity that is further enhanced by the presence of patient-derived BMSCs. They also suggest that this activity is likely relevant to the drug resistance development in some patients. Further elucidation of the mechanism of PIR NF-kappaB regulation could lead to the identification of novel diagnostic biomarkers and/or therapeutic targets for MM treatment.