Ifosfamide, Epirubicin and Etoposide (IEV) Regimen as Salvage and Mobilization Therapy for Refractory or Early Relapsing Patients with Aggressive Non-Hodgkin's Lymphoma

A Review of Advances in Hematopoietic Stem Cell Mobilization and the Potential Role of Notch2 Blockade

Hematopoietic stem cell (HSC) transplantation can be a potential cure for hematological malignancies and some nonhematologic diseases. Hematopoietic stem and progenitor cells (HSPCs) collected from peripheral blood after mobilization are the primary source to provide HSC transplantation. In most of the cases, mobilization by the cytokine granulocyte colony-stimulating factor with chemotherapy, and in some settings, with the CXC chemokine receptor type 4 antagonist plerixafor, can achieve high yield of hematopoietic progenitor cells (HPCs). However, adequate mobilization is not always successful in a significant portion of donors. Research is going on to find new agents or strategies to increase HSC mobilization. Here, we briefly review the history of HSC transplantation, current mobilization regimens, some of the novel agents that are under investigation for clinical practice, and our recent findings from animal studies regarding Notch and ligand interaction as potential targets for HSPC mobilization.

Hydroxylation and N-dechloroethylation of Ifosfamide and deuterated Ifosfamide by the human cytochrome p450s and their commonly occurring polymorphisms

The hydroxylation and N-dechloroethylation of deuterated ifosfamide (d4IFO) and ifosfamide (IFO) by several human P450s have been determined and compared. d4IFO was synthesized with deuterium at the alpha and alpha' carbons to decrease the rate of N-dechloroethylation and thereby enhance hydroxylation of the drug at the 4' position. The purpose was to decrease the toxic and increase the efficacious metabolites of IFO. For all of the P450s tested, hydroxylation of d4IFO was improved and dechloroethylation was reduced as compared with nondeuterated IFO. Although the differences were not statistically significant, the trend favoring the 4'-hydroxylation pathway was noteworthy. CYP3A5 and CYP2C19 were the most efficient enzymes for catalyzing IFO hydroxylation. The importance of these enzymes in IFO metabolism has not been reported previously and warrants further investigation. The catalytic ability of the common polymorphisms of CYP2B6 and CYP2C9 for both reactions were tested with IFO and d4IFO. It was determined that the commonly expressed polymorphisms CYP2B6*4 and CYP2B6*6 had reduced catalytic ability for IFO compared with CYP2B6*1, whereas CYP2B6*7 and CYP2B6*9 had enhanced catalytic ability. As with the wild-type enzymes, d4IFO was more readily hydroxylated by the polymorphic variants than IFO, and d4IFO was not dechloroethylated by any of the polymorphic forms. We also assessed the use of specific inhibitors of P450 to favor hydroxylation in human liver microsomes. We were unable to separate the pathways with these experiments, suggesting that multiple P450s are responsible for catalyzing both metabolic pathways for IFO, which is not observed with the closely related drug cyclophosphamide.

Advances in stem cell mobilization

Use of granulocyte colony stimulating factor (G-CSF)-mobilized peripheral blood hematopoietic progenitor cells (HPCs) has largely replaced bone marrow (BM) as a source of stem cells for both autologous and allogeneic cell transplantation. With G-CSF alone, up to 35% of patients are unable to mobilize sufficient numbers of CD34 cells/kg to ensure successful and consistent multi-lineage engraftment and sustained hematopoietic recovery. To this end, research is ongoing to identify new agents or combinations which will lead to the most effective and efficient stem cell mobilization strategies, especially in those patients who are at risk for mobilization failure. We describe both established agents and novel strategies at various stages of development. The latter include but are not limited to drugs that target the SDF-1/CXCR4 axis, S1P agonists, VCAM/VLA-4 inhibitors, parathyroid hormone, proteosome inhibitors, Groβ, and agents that stabilize HIF. While none of the novel agents have yet gained an established role in HPC mobilization in clinical practice, many early studies exploring these new pathways show promising results and warrant further investigation.

Current status of stem cell mobilization

New advances in effective mobilization of peripheral blood stem cells have permitted a greater proportion of patients to benefit from autologous stem cell transplantation. In this review, the relative merits of peripheral blood and mobilized bone marrow are discussed. All available agents are reviewed. A critical assessment of the appropriate dosing and frequency of available growth factors is undertaken, and the most commonly used chemotherapy plus growth factor combinations are covered. Specific recommendations for patients who are poor mobilizers are dealt with including the role of plerixafor.

Etoposide 1.0 g/m2 or 1.5 g/m2 combined with granulocyte colony-stimulating factor for mobilization of peripheral blood stem cells in patients with malignancy: efficacy and toxicity

BACKGROUND

The purpose of this study was to observe the efficacy and toxicity of etoposide at two dose levels for peripheral blood stem cell (PBSC) mobilization and disease debulking in patients with malignancy. Simultaneously, factors affecting the yield of CD34+ cells were explored.

METHODS

Thirty-eight patients received etoposide 1.0 g/m2 (group A) or 1.5 g/m2 (group B) followed by granulocyte colony-stimulating factor (G-CSF) 300 microg/day for PBSC mobilization in a non-randomized manner. Each group had 19 patients.

RESULTS

The median number of CD34+ cells collected was 17.33 x 10(6)/kg (range 4.85-89.00 x 10(6)/kg) in group A and 26.54 x 10(6)/kg (range 1.85-108.00 x 10(6)/kg) in group B. Altogether, 34/38 (89.5%) patients obtained the target total collection of at least 4 x 10(6) CD34+ cells/kg by a single leukapheresis. Vomiting was the most common grade 3/4 non-hematologic toxicity. For 19 evaluable patients, partial response was achieved in four (21.1%), stable disease in 11 (57.8%) and progressive disease in four (21.1%) patients. All parameters between the two groups did not reach a significant level. With multivariate analysis, the most predictive factor for CD34+ yield of the first leukapheresis was the percentage of CD34+ CD38(-) cells in peripheral blood.

CONCLUSION

These results indicate that etoposide combined with G-CSF is an effective and tolerable regimen for PBSC mobilization, given at a dose of either 1.0 g/m2 or 1.5 g/m2.

Ifosfamide, epirubicin and etoposide rituximab in refractory or relapsed B-cell lymphoma: analysis of remission induction and stem cell mobilization

Chemotherapy with ifosfamide, epirubicin and etoposide (IEV) is an effective treatment regimen for refractory/relapsed non-Hodgkin lymphoma (NHL). Rituximab has been shown to improve response rates, progression-free survival and overall survival in B-cell NHL. This study included 85 patients who were treated with IEV or rituximab-IEV (R-IEV) for refractory/relapsed B-cell NHL. The overall response rate was 40.7% (IEV) versus 68.8% (R-IEV). Fever occurred after 23.4% of IEV and 19.4% of R-IEV cycles. 94.9% of patients mobilized sufficient numbers of CD34+ cells (IEV) versus 93.8% (R-IEV). Fifty-five patients (64.7%) proceeded to high-dose therapy after IEV+/-rituximab. The median survival time was 60.0 months (IEV) and 19.5 months (R-IEV), and has not been reached for patients who received high-dose therapy. The addition of rituximab to IEV salvage chemotherapy increases the response rates in B-cell NHL without affecting stem cell mobilization, but overall survival for patients proceeding to high-dose chemotherapy is not improved.

[High-dose ifosfamide and etoposide regimen as salvage and mobilization therapy for patients with lymphoma]

BACKGROUND AND OBJECTIVE

Several groups have used salvage chemotherapy in relapsed or refractory lymphomas to mobilize peripheral blood stem cells. The objective of this study was to evaluate the antilymphomatous efficacy, the ability of mobilization and the toxicity of a regimen containing high-dose ifosfamide, etoposide, methylprednisolone (IFOVM) and granulocyte colony-stimulating factor (G-CSF).

PATIENTS AND METHOD

Twenty-four patients with relapsed or refractory lymphoma received IFOVM and G-CSF. The median age was 45 years and 13 were males. The histologyc subtypes of lymphoma were: diffuse large B cell (DLBCL) (n = 15), Hodgkin (n = 2), Burkitt (n = 2), mantle cell (n = 2), anaplastic (n = 1), peripheral T-cell (n = 1) and follicular (n = 1).

RESULTS

Two patients died of sepsis within the pancytopenia period. In 17 (77%) of the remaining patients more than 1.5 x 10(6) CD34+ cells/kg (median: 7.7 x 10(6) CD34+ cells/kg) were collected. The median time to peripheral blood stem cells harvest was 17 (range: 13-24) days and 4 patients required 2 procedures of apheresis. Sixteen patients (67%) developed neutropenic fever. The median time to achieve granulocyte cell count > 1 x 10(9)/l and platelet count > 20 x 10(9)/l was 15 and 16 days, respectively. The only factor predicting successful mobilization was the diagnosis of DLBCL (p = 0.04). Ten patients underwent peripheral blood stem cells transplantation.

CONCLUSIONS

The regimen IFOVM and G-CSF allows an effective peripheral blood stem cells mobilization in patients with lymphoma, particularly in those with DLBCL, but it is associated with significant toxicity.

Detection and quantification of functionally defined hematopoietic progenitor cells and tissue specific mRNA within the peripheral blood of myeloma patients after administration of granulocyte colony-stimulating factor and erythropoietin

OBJECTIVE

Hematopoietic progenitor cells (HPC) as well as tissue committed stem cells expressing mRNA specific to various somatic tissues are thought to be part of the CD34+ bone marrow compartment. In this study, we explore and quantify their mobilization in patients with multiple myeloma undergoing chemotherapy upon administration of granulocyte colony-stimulating factor (G-CSF) plus/minus erythropoietin (EPO).

PATIENTS AND METHODS

HPC were quantified by flow cytometry and functional assays within the blood of healthy donors and myeloma patients before and after chemotherapy followed by G-CSF or G-CSF + EPO given subcutaneously. The mRNA expression was studied by quantitative polymerase chain reaction (PCR). Cytokines and peripheral blood protease levels were measured by an enzyme-linked immunosorbent assay.

RESULTS

EPO did not significantly alter the number of HPC mobilized by G-CSF alone, and mRNA specific for liver, brain, muscle and kidney was detected in both treatment groups. Quantitative PCR analysis revealed a 2.7-fold increased expression of glial fibrillary acidic protein after G-CSF + EPO administration compared to G-CSF alone (P = 0.003). The concentration of G-CSF rose from 62 +/- 22 pg/mL and 48 +/- 10 pg/mL to 28 +/- 9 ng/mL and 85 +/- 10 ng/mL after 10 d of treatment with G-CSF and G-CSF + EPO, respectively. The concentration of neutrophil elastase (NE) rose only in the G-CSF group by a factor 1.5.

CONCLUSION

The alteration of G-CSF and NE levels as well as the expression of tissue committed RNA after the administration of EPO in addition to G-CSF indicate that different growth factors mobilize different stem cells that might potentially be used for the support of tissue repair in future treatment protocols.

Ifosfamide, epirubicin, and etoposide (IEV) mobilize peripheral blood stem cells more efficiently than cyclophosphamide/etoposide

High-dose chemotherapy with autologous stem cell support is an effective treatment in advanced multiple myeloma. In this study, we compare chemotherapy with ifosfamide, epirubicin, and etoposide (IEV) or cyclophosphamide and etoposide (CE) in 47 patients with multiple myeloma with regard to stem cell mobilization, toxicity, and tumor response. The proportion of patients reaching the threshold of >6 x 10(6) CD34+ cells/kg body weight was significantly higher in the IEV group (97% vs 71%), and more CD34+ cells (10 x 10(6) vs 3.5 x 10(6) cells/kg; p = 0.002) could be collected by the first leukapheresis associated with less leukaphereses needed. Non-hematopoietic side effects were mild with nausea being more frequent after IEV treatment (30% vs 7%). Grade 3/4 neutropenia (thrombocytopenia) occurred in 89 and 100% (55 and 44%) of the patients. There was one treatment-related death due to septic shock in the IEV group. Grade 3/4 anemia was more frequent in the IEV group (19% vs 0%). Forty-two percent (IEV) and 50% (CE) received inpatient treatment for neutropenic fever. In 20 and 7% of the patients, a partial response was observed after IEV and CE. However, the overall response rate (complete response and partial tumor response) after mobilization and tandem high-dose chemotherapy was 75% after IEV and 78% after CE and, thus, independent of the mobilization. In summary, both treatment protocols can readily be used for the mobilization of peripheral blood stem cells with comparable major toxicities and similar tumor response rates. However, the efficiency of the stem cell mobilization was significantly higher after IEV treatment.

Metabolism and transport of oxazaphosphorines and the clinical implications

The oxazaphosphorines including cyclophosphamide (CPA), ifosfamide (IFO), and trofosfamide represent an important group of therapeutic agents due to their substantial antitumor and immuno-modulating activity. CPA is widely used as an anticancer drug, an immunosuppressant, and for the mobilization of hematopoetic progenitor cells from the bone marrow into peripheral blood prior to bone marrow transplantation for aplastic anemia, leukemia, and other malignancies. New oxazaphosphorines derivatives have been developed in an attempt to improve selectivity and response with reduced toxicity. These derivatives include mafosfamide (NSC 345842), glufosfamide (D19575, beta-D-glucosylisophosphoramide mustard), NSC 612567 (aldophosphamide perhydrothiazine), and NSC 613060 (aldophosphamide thiazolidine). This review highlights the metabolism and transport of these oxazaphosphorines (mainly CPA and IFO, as these two oxazaphosphorine drugs are the most widely used alkylating agents) and the clinical implications. Both CPA and IFO are prodrugs that require activation by hepatic cytochrome P450 (CYP)-catalyzed 4-hydroxylation, yielding cytotoxic nitrogen mustards capable of reacting with DNA molecules to form crosslinks and lead to cell apoptosis and/or necrosis. Such prodrug activation can be enhanced within tumor cells by the CYP-based gene directed-enzyme prodrug therapy (GDEPT) approach. However, those newly synthesized oxazaphosphorine derivatives such as glufosfamide, NSC 612567 and NSC 613060, do not need hepatic activation. They are activated through other enzymatic and/or non-enzymatic pathways. For example, both NSC 612567 and NSC 613060 can be activated by plain phosphodiesterase (PDEs) in plasma and other tissues or by the high-affinity nuclear 3'-5' exonucleases associated with DNA polymerases, such as DNA polymerases and epsilon. The alternative CYP-catalyzed inactivation pathway by N-dechloroethylation generates the neurotoxic and nephrotoxic byproduct chloroacetaldehyde (CAA). Various aldehyde dehydrogenases (ALDHs) and glutathione S-transferases (GSTs) are involved in the detoxification of oxazaphosphorine metabolites. The metabolism of oxazaphosphorines is auto-inducible, with the activation of the orphan nuclear receptor pregnane X receptor (PXR) being the major mechanism. Oxazaphosphorine metabolism is affected by a number of factors associated with the drugs (e.g., dosage, route of administration, chirality, and drug combination) and patients (e.g., age, gender, renal and hepatic function). Several drug transporters, such as breast cancer resistance protein (BCRP), multidrug resistance associated proteins (MRP1, MRP2, and MRP4) are involved in the active uptake and efflux of parental oxazaphosphorines, their cytotoxic mustards and conjugates in hepatocytes and tumor cells. Oxazaphosphorine metabolism and transport have a major impact on pharmacokinetic variability, pharmacokinetic-pharmacodynamic relationship, toxicity, resistance, and drug interactions since the drug-metabolizing enzymes and drug transporters involved are key determinants of the pharmacokinetics and pharmacodynamics of oxazaphosphorines. A better understanding of the factors that affect the metabolism and transport of oxazaphosphorines is important for their optional use in cancer chemotherapy.

Therapeutic results in patients with relapsed diffuse large B cell Non-Hodgkin's lymphoma achieving complete response only after autologous stem cell transplantation

Forty patients with relapsed diffuse large B cell lymphoma (DLBCL) autografted in partial response (PR) (n = 23) or in refractory relapse (RR) (n = 17) achieved complete remission (CR) after autologous stem cell transplantation (ASCT). Salvage treatment consisted of ifosphamide, epirubicin and etoposide (IEV) in 33 patients and Cisplatinum, ARA-C and dexamethasone (DHAP) in 7 patients. All PR and 8 RR patients were conditioned with BEAM, while 9 RR cases received the BCV regimen. There were no significant differences between the two groups as age, serum LDH, duration of CR1 and IPI at relapse are concerned. Relapse rate after ASCT was 39% in PR group as opposed to 88% in RR group (p = 0.003). Median relapse free survival from ASCT was 6 months for RR patients as opposed to 34 months for PR patients (p = 0.003); median overall survival from ASCT was 10 months for RR subset as opposed to not reached for RR subgroup (p = 0.001). These data demonstrate that CR achieved after ASCT in DLBCL patients who are refractory to previous salvage therapy does not result in long-term disease control. Alternative preparative regimens, allogeneic SCT and/or monoclonal antibodies in the post-ASCT phase should be considered for RR patients despite CR achievement.