Effect of rituximab on peripheral blood stem cell mobilization and engraftment kinetics in non-Hodgkin's lymphoma patients

Mobilization with reduced cyclophosphamide for autologous stem cell transplantation is feasible in patients with systemic sclerosis

OBJECTIVES

To assess the feasibility of reduced cyclophosphamide dosing in the setting of mobilization chemotherapy prior to high dose chemotherapy and autologous stem cell transplantation in patients with SSc. The primary end point was the occurrence of 'poor mobilization' when using different cyclophosphamide dosing. The second end point was to analyse potential risk factors for difficult stem cell mobilization in this cohort of patients with SSc.

METHODS

This single-centre study retrospectively reviewed 32 patients with SSc who underwent autologous stem cell transplantation. We analysed the occurrence of 'poor mobilization' (defined as CD34+ progenitor cell count <2 × 106/kg body weight, the use of increasing G-CSF dose, the use of plerixafor, or leukapheresis on >2 consecutive days) in different cyclophosphamide mobilization regimens: We herein compared low dose (2 × 1-1.5 g/m2) cyclophosphamide vs high dose (2 × 2 g/m2) for mobilization.

RESULTS

Higher dosing of cyclophosphamide seems not to be beneficial regarding stem cell collection as there was no significant difference in stem cell yield between high dose and reduced dose cyclophosphamide (6.2 vs 5.2 × 106/kg bodyweight after CD34+ enrichment). Furthermore, higher doses of cyclophosphamide might be associated with more side effects; this difference was, however, not statistically significant. Lower bodyweight and BMI (P < 0.001) as well as rituximab pre-therapy (P < 0.05) and cardiac involvement (P < 0.01) might negatively impact stem cell collection independently from the chosen regimen.

CONCLUSION

Our data demonstrate that a reduced cyclophosphamide mobilization regimen seems to be feasible. Risk factors for poor mobilization might be low bodyweight, prior rituximab therapy and cardiac involvement.

High-dose rituximab in combination with autologous stem cell transplantation for relapsed or refractory diffuse large B cell lymphoma

OBJECTIVES

The aim of this study was to evaluate the efficacy and toxicity of high-dose rituximab (HD-R) in combination with autologous stem cell transplantation (auto-SCT) in patients with relapsed or refractory diffuse large B cell lymphoma (DLBCL).

METHODS

There were 22 patients in the HD-R group, to whom rituximab was administered during stem cell mobilization (375mg/m² 1 day before and 7 days after chemotherapy) and after transplantation (1000mg/m² on days +1 and +8). In the control group, the procedure was the same as that in the HD-R group but without rituximab. We observed the safety, tolerability, adverse effects and immune reconstitution of HD-R therapy. The log-rank test, univariate analysis and multivariate Cox regression analysis were used to evaluate the effect of HD-R on survival.

RESULTS

In total, 22 relapsed or refractory DLBCL patients were treated with HD-R. No dose-limiting toxicities were observed except for CD19⁺ B cell reconstruction in the first 6 months after SCT. There were 20 relapsed or refractory DLBCL patients in the control group. The 3-year progression-free survival (PFS) and overall survival (OS) greatly improved in the HD-R group compared to that in the control group (63.8% vs. 35.0%, P=0.028 and 80.1% vs. 50.0%, P=0.035, respectively). The univariate and multivariate analyses demonstrated that HD-R and the time to relapse were independent prognostic factors for OS and PFS.

CONCLUSION

HD-R in combination with auto-SCT is a feasible and promising treatment for patients with relapsed or refractory DLBCL.

Emerging strategies for enhancing the homing of hematopoietic stem cells to the bone marrow after transplantation

Bone marrow failure is the primary cause of death after nuclear accidents or intentional exposure to high or low doses of ionizing radiation. Hematopoietic stem cell transplantation is the most potent treatment procedure for patients suffering from several hematopoietic malignancies arising after radiation injuries. Successful hematopoietic recovery after transplantation depends on efficient homing and subsequent engraftment of hematopoietic stem cells in specific niches within the bone marrow. It is a rapid and coordinated process in which circulating cells actively enter the bone marrow through the process known as transvascular migration, which involves the tightly regulated relay of events that finally leads to homing of cells in the bone marrow. Various adhesion molecules, chemokines, glycoproteins, integrins, present both on the surface of stem cells and sinusoidal endothelium plays a critical role in transvascular migration. But despite having an in-depth knowledge of homing and engraftment and the key events that regulate it, we are still not completely able to avoid graft failures and post-transplant mortalities. This deems it necessary to design a flawless plan for successful transplantation. Here, in this review, we will discuss the current clinical methods used to overcome graft failures and their flaws. We will also discuss, what are the new approaches developed in the past 10-12 years to selectively deliver the hematopoietic stem cells in the bone marrow by adopting proper targeting strategies that can help revolutionize the field of regenerative and translational medicine.

A review of rituximab, the first anti-CD20 monoclonal antibody used in the treatment of B non-Hodgkin's lymphomas

Rituximab is a type I anti-CD20 monoclonal antibody, which stabilizes CD20 on lipid rafts, promoting antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity activities. It is the first targeted therapy used in B-cell malignancies and has revolutionized their treatment, without excess of toxicity. In combination with chemotherapy, it has significantly improved response rates and progression-free survival and, for some of them, overall survival of patients with diffuse large B-cell lymphoma, follicular lymphoma, marginal zone lymphoma, mantle cell lymphoma. Moreover, it has been shown to improve progression-free survival in maintenance in follicular lymphoma as well as mantle cell lymphoma. Improvement of its efficacy includes exploration of resistance mechanisms, pharmacokinetics parameters, role of vitamin D and evaluation of subcutaneous route, among others.

Autologous peripheral blood stem cell mobilization following dose-adjusted cyclophosphamide, doxorubicin, vincristine, and prednisolone chemotherapy alone or in combination with rituximab in treating high-risk non-Hodgkin's lymphoma

Background

The regimen of cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP) is an efficient treatment of non-Hodgkin’s lymphoma (NHL). This study aimed to assess the efficacy and toxicity of dose-adjusted CHOP alone or in combination with rituximab (R-CHOP) by examining the stem cell mobilization in NHL patients. Factors affecting the collection of CD34⁺ cells were also explored.

Methods

Our retrospective study included 39 patients eligible for autologous stem cell transplantation: 14 patients who expressed CD20 and were financially eligible received R-CHOP for autologous peripheral blood stem cell (APBSC) mobilization; the remaining 25 patients received CHOP.

Results

The median CD34⁺ cell yield was 7.01 × 10⁶ cells/kg body weight (range 1.49–28.39 × 10⁶ cells/kg body weight), with only two patients failing to meet the target CD34⁺ cell harvest of ≥2.0 × 10⁶ cells/kg body weight. The median number of apheresis procedures per patient was 1 (range 1–3). The APBSC mobilization yield of the CHOP group appeared to be higher than that of the R-CHOP group (P = 0.005), whereas the success rate was similar between groups. R-CHOP elevated the complete response (CR) rate in B cell lymphoma patients as compared with CHOP (P = 0.01). No significant differences in toxicity or engraftment were observed between the two groups.

Conclusion

The present study demonstrated that dose-adjusted CHOP chemotherapy effectively mobilized APBSCs in NHL patients and that the addition of rituximab to dose-adjusted CHOP chemotherapy elevated the CR rate for patients with B-cell lymphoma.

Hematopoietic cell transplantation for B-cell lymphoma: an update

BACKGROUND

B-cell lymphoma comprises the majority of non-Hodgkin lymphomas worldwide. Hematopoietic cell transplantation (HCT) is used for patients with high-risk, relapsed, or refractory B-cell lymphoma.

METHODS

The current medical literature and the results of recently published trials were reviewed to provide an update on the most common indications for HCT in B-cell lymphoma.

RESULTS

Autologous HCT has evolving and new roles in the treatment of patients with high-risk diffuse large B-cell cell lymphoma, mantle cell lymphoma, and HIV-related lymphoma. Reduced-intensity conditioning has largely replaced older myeloablative conditioning regimens, making allogeneic transplantation safer for more patients with lymphoma.

CONCLUSIONS

The indication and timing of HCT depend on the patient's histology, age, and response to previous therapies. HCT is an essential component in the armamentarium to treat B-cell lymphoma.

How to determine post-RCHOP therapy for risk-tailored adult patients with diffuse large B-cell lymphoma, addition of maintenance rituximab or observation: multicenter experience

BACKGROUND

In international prognostic index (IPI) risk-tailored adult patients with diffuse large B-cell lymphoma (DLBCL), it is still unclear whether the addition of maintenance rituximab (MR) improves progression-free (PFS) and overall survival (OS), after RCHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone) therapy.

METHODS

In our study, 207 patients (age: 21-59 years) received six 14-day cycles of RCHOP and gained overall response. After RCHOP, 98 patients were enrolled in the observation (OBS) arm. 109 patients continued to receive MR therapy.

RESULTS

In IPI risk <2 profile, PFS at 5 years reached 72.9% (MR arm) versus 56% (OBS arm) (P = 0.033). In IPI risk ≥2 profile, PFS estimation at 5 years was 44.9% (MR arm) versus 33.5% (OBS arm) (P = 0.006). It is noteworthy that patients with IPI ≥2 who received MR achieved PFS similar to that for patients in the OBS arm with the IPI <2, 44.9% versus 56% (P = 0.97). In patients with an IPI <2, OS at 5 years was 83.2% (MR arm) versus 81.2% (OBS arm) (P = 0.708). In patients with an IPI ≥2, 5-year OS estimation was 44.6% (MR arm) versus 40.5% (OBS arm) (P = 0.067). Subgroup analysis of patients with an IPI ≥3 risk profile shows a survival benefit for patients receiving MR. OS at 5 years was 62% (MR arm) versus 49% (OBS arm), (P = 0.033).

CONCLUSIONS

In conclusion, maintenance rituximab after RCHOP improves progression-free survival. In addition, overall survival is improved for patients with an IPI ≥3 risk profile receiving MR.

Hematopoietic Cell Transplantation for Lymphomas

Background

The heterogeneity of lymphomas results in numerous treatment options, including both autologous and allogeneic hematopoietic cell transplantation. However, the type of transplantation, the timing the procedure, and the selection of suitable patients for transplant continue to evolve.

Methods

We reviewed the current medical literature to provide a succinct synthesis for the most common types of lymphoma and the indications for transplantation.

Results

This review discusses the outcomes of autologous and allogeneic transplantation for patients with diffuse large B-cell lymphoma, follicular lymphoma, HIV-associated lymphomas, mantle cell lymphoma, T-cell lymphoma, and Hodgkin lymphoma.

Conclusions

Each of these histologies differs in the indications and timing for transplantation. However, ongoing clinical trials support the continuing role of both autologous and allogeneic transplantation for lymphoma management.

The role of rituximab in autologous and allogeneic hematopoietic stem cell transplantation for non-Hodgkin's lymphoma

The addition of rituximab to chemotherapy has substantially changed the treatment strategies for patients with B-cell lymphomas. Rituximab, combined with standard chemotherapy regimens, shows consistently improved results compared with chemotherapy alone and has been extensively employed in both newly diagnosed and relapsed patients with B-cell lymphoma. Because of its low toxicity profile and its potent antilymphoma activity mediated through direct apoptotic and indirect effector mechanisms, rituximab also has been actively incorporated into stem cell transplantation (SCT) protocols to attain a state of minimal disease, provide a safe and effective method for in vivo purging prior to autologous SCT, and promote graft-versus-lymphoma effects in allogeneic SCT. This review compiles the still immature but rapidly growing data on this combined modality.

Impact of pre-transplant rituximab on survival after autologous hematopoietic stem cell transplantation for diffuse large B cell lymphoma

Incorporation of the anti-CD20 monoclonal antibody rituximab into front-line regimens to treat diffuse large B cell lymphoma (DLBCL) has resulted in improved survival. Despite this progress, however, many patients develop refractory or recurrent DLBCL and then undergo autologous hematopoietic stem cell transplantation (AuHCT). It is unclear to what extent pre-transplant exposure to rituximab affects outcomes after AuHCT. Outcomes of 994 patients receiving AuHCT for DLBCL between 1996 and 2003 were analyzed according to whether rituximab was (n = 176; +R cohort) or was not (n = 818; -R cohort) administered with front-line or salvage therapy before AuHCT. The +R cohort had superior progression-free survival (PFS; 50% vs 38%; P = .008) and overall survival (OS; 57% vs 45%; P = .006) at 3 years. Platelet and neutrophil engraftment were not affected by exposure to rituximab. Nonrelapse mortality (NRM) did not differ significantly between the 2 cohorts. In multivariate analysis, the +R cohort had improved PFS (relative risk of relapse/progression or death, 0.64; P < .001) and improved OS (relative risk of death, 0.74; P = .039). We conclude that pre-transplant rituximab is associated with a lower rate of progression and improved survival after AuHCT for DLBCL, with no evidence of impaired engraftment or increased NRM.

Dose-dense and high-dose chemotherapy plus rituximab with autologous stem cell transplantation for primary treatment of diffuse large B-cell lymphoma with a poor prognosis: a phase II multicenter study

BACKGROUND

We investigated the addition of rituximab to dose-dense and high-dose chemotherapy with autologous stem cell transplantation in patients with untreated poor-prognosis diffuse large B-cell lymphoma.

DESIGN AND METHODS

Ninety-four young patients (age, 18-60) with stage III-IV diffuse large B-cell lymphoma at intermediate/high or high risk according to the age-adjusted International Prognostic Index were enrolled into a phase II trial. The treatment was as follows: four courses of bi-weekly rituximab-cyclophosphamide-epirubicin-vincristine-prednisone (R-MegaCEOP14), two courses of rituximab-mitoxantrone-cytarabine-dexamethasone (R-MAD) and carmustine-etoposide-cytarabine-melphalan (BEAM) with autologous stem cell transplantation.

RESULTS

The complete response and toxic death rates were 82% and 5%, respectively. Failure-free survival and overall survival rates at 4 years were 73% and 80%, respectively. The outcomes of these patients were retrospectively compared to those of 41 patients with similar characteristics enrolled into a previous phase II trial of high-dose chemotherapy without rituximab. This historical group was treated with eight weekly infusions of methotrexate-doxorubicin-cyclophosphamide-vincristine-prednisone-bleomycin (MACOP-B), two courses of MAD and BEAM with autologous stem cell transplantation. The 4-year failure-free survival rates for the rituximab and historical groups were 73% versus 44%, respectively (p=0.001); the 4-year overall survival rates were 80% and 54%, respectively (p=0.002). A Cox's multivariable model was applied to adjust the effect of treatment for unbalanced or important prognostic factors: failure and death risks were significantly reduced in the rituximab group compared to the historical group, with an adjusted hazard ratio of 0.44 (p=0.01) for failure-free survival and 0.46 (p=0.02) for overall survival.

CONCLUSIONS

These results suggest that the addition of rituximab to high-dose chemotherapy is effective and safe in diffuse large B-cell lymphoma with a poor-prognosis and such regimens need to be compared to dose-dense chemoimmunotherapy without autologous stem cell transplantation in randomized trials.

A randomized trial of etoposide and G-CSF with or without rituximab for PBSC mobilization in B-cell non-Hodgkin's lymphoma

Some reports have suggested that rituximab administration before PBSC mobilization may adversely affect PBSC yield. We conducted a prospective randomized trial of PBSC mobilization using etoposide and G-CSF with or without rituximab to determine whether its addition would adversely affect CD34+ cell yield in patients with non-Hodgkin's lymphoma. Twenty seven patients were mobilized with etoposide and G-CSF and 28 with etoposide, G-CSF and rituximab. There were no adverse consequences of rituximab on CD34+ cell yield, or hematopoietic recovery or immunoglobulin levels after transplantation.

Follicular lymphomas

Follicular lymphomas constitute approximately 30% of all non-Hodgkin lymphomas. These lymphomas are characterized by at least partially follicular growth pattern, but diffuse areas may be present. The proportions of follicular or diffuse areas vary also from case to case, which seems to be associated with prognosis. Follicular lymphomas should not be divided into distinct subtypes, but rather shows a continuous gradation in the number of large cells. On the bases of this grading, three groups have been defined: grades 1-3. There is a consensus that grade 3 follicular lymphomas, namely grade 3b, should be discriminated from lower-grade cases. The cells of follicular lymphomas express surface immunoglobulin, more frequently IgM+/-IgD>IgG>IgA, B-cell-associated antigens, CD10+/-; they are CD5-, CD23-/+, CD43-, and CD11c-. Follicular lymphomas express bcl-2 proteins, which is useful in distinguishing reactive from neoplastic follicles. t(14;18) is present in 70-95% of follicular lymphomas, involving rearrangement of bcl-2 gene. Clinical behavior of follicular lymphomas is heterogeneous and differs according to the histologic grade and extension of disease. Moreover, the evaluation of these malignancies is conditioned by therapeutic decision, which is also determined by main prognostic factors. The International Prognostic Index for aggressive lymphomas is not optimal for follicular lymphomas. Conversely, the Italian Lymphoma Intergroup Index and, more recently, the Follicular Lymphoma International Prognostic Index (FLIPI), designed in pre-rituximab era, seem to correlate well with outcome. Several active therapeutic approaches from the "wait and watch" strategy to the allogeneic transplantation are available for management of patients with follicular lymphoma. Therapeutic decision is mostly conditioned by patient's characteristics, stage, histologic grade, tumor burden, and risk-predicting factors.

Mobilization of peripheral blood progenitor cells after DHAP regimen with or without rituximab: a large multicenter comparative study in patients with malignant lymphoma

DHAP regimen is commonly used in patients with lymphoma. It is routinely used in combination with the monoclonal anti-CD20 antibody rituximab (R-DHAP), particularly for peripheral blood stem cell (PBSC) mobilization. The aim of this study was to assess the impact of rituximab on PBSC mobilization in patients with lymphoma receiving DHAP chemotherapy. We retrospectively reviewed the data of patients treated by DHAP or R-DHAP regimens as PBSC mobilization protocol between July 1998 and June 2005. Sixty-nine patients were included in the study: 21 in the DHAP group and 48 in the R-DHAP group. Both groups were not statistically different in term of clinical and biological presentation of the disease. The first cytapheresis was performed at day 10 in the R-DHAP group versus day 11 in the DHAP group. In contrast, the number of circulating CD34(+) cells was higher, but not significant, in the R-DHAP group than the DHAP group, namely 9.7x10(6) CD34(+) cells/kg and 6.1x10(6) CD34(+) cells/kg, respectively. Finally, the complete remission status at time of harvest was the only one factor associated with poor mobilization on multivariate analysis. In conclusion, our results show that rituximab does not impair PBSC collection.

Rituximab-ESHAP as a mobilization regimen for relapsed or refractory B-cell lymphomas: a comparison with ESHAP

BACKGROUND

It has previously been shown that ESHAP was an effective mobilization regimen for patients with pretreated lymphoma. To extend these observations, the efficacy and feasibility of rituximab plus ESHAP regimen in CD20+ B-cell NHL were assessed.

STUDY DESIGN AND METHODS

The mobilization efficacy and engraftment characteristics were compared in the 22 patients who received the rituximab plus ESHAP (R-ESHAP) with 33 historical controls who received ESHAP.

RESULTS

The two treatment groups were well matched in patient characteristics. In the R-ESHAP group, 62 pheresis procedures were performed. Apheresis procedures were started on median Day 16 (range, Days 13-18). The median number of collected CD34+ cells was 10.6 x 10(6) per kg (range, 4.9 x 10(6)-52.6 x 10(6)/kg). Nineteen (95%) patients achieved optimal peripheral blood hematopoietic progenitor cell (PBPC) collection, defined as at least 5 x 10(6) CD34+ cells per kg. There were no significant differences between the two groups with respect to mobilization efficacy. Sixteen patients in the R-ESHAP group (73%) underwent autologous peripheral blood progenitor cell transplantation (APBPCT). The median time to absolute neutrophil count at least 0.5 x 10(9) per L was 10 days (range, 8-17 days), and the median time to a platelet count of at least 20 x 10(9) per L was 12 days (range, 7-27 days). Lymphocyte recovery was slower in the R-ESHAP group, but the rate of infectious complications was similar in the two groups. In the R-ESHAP group, the 2-year overall survival and progression-free survival after APBPCT were 63.2 and 57.4 percent, respectively.

CONCLUSION

Addition of rituximab to ESHAP chemotherapy did not have any adverse effects on PBPC mobilization. Further studies are needed, however, to determine whether addition of rituximab improves outcomes.

Rituximab does not compromise the mobilization and engraftment of autologous peripheral blood stem cells in diffuse-large B-cell lymphoma

To investigate effects of the preautografting administration of rituximab on the mobilization and engraftment of peripheral blood stem cells (PBSC), we retrospectively analyzed the outcomes of 43 newly diagnosed diffuse-large B-cell lymphoma patients who received CHOP chemotherapy with or without rituximab as a first-line treatment before autologous PBSC transplantation (PBSCT). There was no difference in the number of CD34(+) cells among PBSC between the non-rituximab and the rituximab groups. Although B-cells were completely depleted from PBSC in the rituximab group, we found no difference in the expression of CXCR-4, VLA-4 and c-Kit on PBSC, indicating that rituximab did not affect the expression of these adhesion molecules, which might be involved in the mechanism of mobilization. There was no significant difference in the recovery of neutrophils and platelets, transplant-related toxicity and post-transplant complications between the two groups. Despite the short follow-up, there was no significant difference in progression-free survival between the two groups. These results indicated no adverse effect of rituximab on the mobilization and engraftment of PBSC. Larger studies are required to determine the impact of rituximab on the mobilization and function of PBSC as well as whether a survival advantage exists in patients who undergo auto-PBSCT with rituximab.

High-dose rituximab does not negatively affect peripheral blood stem cell mobilization kinetics in patients with intermediate-grade non-Hodgkin's lymphoma

Rituximab, an anti-CD20 human-mouse chimeric monoclonal antibody has been shown to improve response rates when it is combined with standard salvage chemotherapy in patients with relapsed or refractory intermediate-grade B-cell non-Hodgkin's lymphoma. A vast majority of these patients subsequently undergo high-dose therapy followed by stem cell transplantation. However, the impact of rituximab on stem cell mobilization kinetics is not well characterized. The purpose of this study was to study the effect of high-dose rituximab given with chemotherapy on stem cell mobilization in patients with intermediate-grade B-cell non-Hodgkin's lymphoma. Thirty-six patients received ifosfamide, etoposide, and rituximab followed by filgrastim for stem cell mobilization. The chemotherapy regimen was well tolerated. Thirty-four of 36 patients (94%) were able to mobilize at least 2 x 10(6) CD34+ cells/kg body weight after a median of 2 apheresis procedures. The median CD34+ cell dose collected per kilogram of recipient body weight was 6.5 x 10(6) (range, 4.65-31.15). All patients who subsequently underwent high-dose chemotherapy and stem cell transplantation experienced sustained engraftment. In conclusion, high-dose rituximab given during stem cell mobilization does not negatively affect stem cell mobilization kinetics.

Rituximab added to an intensified salvage chemotherapy program followed by autologous stem cell transplantation improved the outcome in relapsed and refractory aggressive non-Hodgkin lymphoma

We investigated the addition of rituximab to an intensified salvage program followed by a myeloablative course with autologous stem cell transplantation (ASCT) in patients with relapsed or refractory aggressive non-Hodgkin lymphoma (NHL). Patients with relapsed or progressive aggressive NHL were treated with two cycles of conventional salvage chemotherapy (DHAP) followed by high-dose sequential chemotherapy (cyclophosphamide, methotrexate with vincristine and etoposide) and a final myeloablative course (BEAM) with ASCT. Rituximab (375 mg/m(2)) was administered at each treatment cycle. This cohort was compared with a historical control group of patients treated with the same chemotherapy but without rituximab. Patients from both groups were matched by duration of first remission and lactate dehydrogenase serum levels. Forty-five patients were treated with chemotherapy and 22 with immunochemotherapy. The overall response rates (ORR) at the final evaluation were 63% for the immunochemotherapy group and 42% for the chemotherapy group (p = 0.330). In the historical controlled analysis freedom from second failure (FF2F) at 2 years in the immunochemotherapy group was 57% and overall survival (OS) was 77%. FF2F in the chemotherapy group was 18% (p = 0.0051) and OS was 37% (p = 0.0051). In the matched-pair analysis, FF2F was 58% in the immunochemotherapy group compared to 16% in the chemotherapy group (p = 0.0517); OS was 74 vs 33%, respectively (p = 0.0424). The toxicity was tolerable and comparable in both groups. The addition of rituximab to an intensified salvage chemotherapy regimen seems to improve the prognosis. However, only prospective randomized trial can offer sufficient data of the value of rituximab in relapsed and refractory aggressive NHL.

Effect of rituximab on the long-term outcome after high-dose therapy for relapsed B-cell non-Hodgkin’s lymphoma

To better define the role of rituximab in salvage and high-dose therapy (HDT) for relapsed or refractory non-Hodgkin's lymphoma (NHL), patients treated before the implementation of rituximab in salvage and HDT (n = 57, control group) were compared with patients with rituximab included in this procedure (n = 36, study group). All patients had been antibody-naive at this point, and analyses were performed separately for 22 and 31 patients with aggressive, and 14 and 26 patients with indolent NHL, respectively. All patients received two courses of salvage therapy, predominantly dexamethasone, BCNU, etoposide, cytosine arabinoside, melphalan. Conditioning regimens included BCNU, etoposide, cytosine arabinoside, melphalan; BCNU, etoposide, cytosine arabinoside, cyclophosphamide or total body irradiation and cyclophosphamide, with rituximab added for patients in the study group. Despite the absence of differences in stem cell collection, haematopoietic recovery was delayed in patients with aggressive NHL treated in the study group: median days to absolute neutrophil count more than 0.5 x 10(9)/l, 11 vs 10 (p = 0.01), and platelets more than 20 x 10(9)/l, 14 vs 11 (p = 0.0005), with an increased requirement for platelet transfusions. No similar observations were made in indolent lymphoma patients. Remission rates were superior for patients with aggressive NHL in the study group. With a median follow-up of 7.25 and 4.5 years, this resulted in an improvement in OS at 4.5 years: 67 vs 45% (95% confidence interval, 47-87% vs 28-64%; p = 0.0468). For patients with indolent lymphoma, no comparable benefit was detectable. Our data support the use of rituximab in HDT for patients with aggressive NHL. For patients with indolent NHL, only longer follow-up and/or randomized trials may help to fully determine the impact of rituximab on the outcome after HDT.

Poor mobilization is an independent prognostic factor in patients with malignant lymphomas treated by peripheral blood stem cell transplantation

Haemopoietic stem cell therapy is an increasingly adopted procedure in the treatment of patients with malignant lymphoma. In this retrospective analysis, we evaluated 262 patients, 57 (22%) with Hodgkin's and 205 (78%) with non-Hodgkin's lymphomas (NHL), and 665 harvesting procedures in order to assess the impact of poor mobilization on survival and to determine the factors that may be predictive of CD34(+) poor mobilization. The mobilization chemotherapy regimens consisted of high-dose cyclophosphamide in 92 patients (35.1%) and a high-dose cytarabine-containing regimen (DHAP in 87 patients -(33.2%), MAD in 83 (31.7%)). The incidence of poor mobilizers (<2 x 10(6) CD34(+) cells/kg) was 17.9% overall, with a 10% of very poor mobilizers (< or = 1 x 10(6)/kg). Refractory disease status and chemotherapeutic load (>3 regimens) before mobilization played a negative role and were associated with poor mobilization. Survival analysis of all harvested patients showed an overall survival at 3 years of 71% in good mobilizers vs 33% in poor mobilizers (P=0.002). The event-free survival at 3 years was 23% in poor mobilizers and 58% in good mobilizers (P=0.04). We conclude that in NHL patients, poor mobilization status is predictive of survival.

Randomised comparison of two B-cell purging protocols for patients with B-cell non-Hodgkin lymphoma: in vivo purging with rituximab versus ex vivo purging with CliniMACS CD34 cell enrichment device

We investigated the feasibility, safety and efficacy of two B-cell purging methods in patients with CD20+ non-Hodgkin lymphoma (NHL) receiving autologous stsem cell transplantation. Myeloid and immune recoveries between the methods were compared. Twenty-seven patients were randomised to either in vivo purging with rituximab or ex vivo purging by CD34+ cell selection. Both purging methods were efficient at eliminating B-cells in infusates. When compared with in vivo purging, ex vivo purging was associated with CD34+ cell loss and delayed median neutrophil (10 d vs. 11 d) and platelet (12.5 d vs. 17 d) count recoveries. Lymphocyte recovery was similar in both groups, but immunoglobulin recovery was delayed after in vivo purging. Late-infectious complications were few in both arms. At a median follow-up of 27 months, 2-year probabilities of event-free survival (EFS) rates were 81% for in vivo purging and 76% for ex vivo purging (P = 0.66). When compared with 53 unpurged patients, all 27 purged patients had improved 3-year probabilities of overall survival (89% vs. 70%, P = 0.014) and a trend for improved EFS (78% vs. 57%, P = 0.075). In conclusion, although both purging methods were feasible and safe, rituximab purging was superior as it did not impair CD34+ cell mobilisation and was associated with faster myeloid recovery. Further studies are needed to determine whether rituximab purging is more effective than the use of unpurged autografts.

Autologous transplantation in patients with relapsed or high-grade follicular lymphoma provides long term disease-free survival and best median duration of response

The best treatment option for patients with relapsed or high-grade follicular lymphoma (FL) is unknown. In spite of major advances in the therapy for FL, disease-free survival remains short, and median time to progression is just over a year. Autologous stem cell transplantation in patients with relapsed FL is safe and appears to improve disease-free survival. In an attempt to examine whether autologous stem cell transplantation provides long-term disease control in patients with relapsed or high-grade FL, we retrospectively evaluated our experience and analyzed the outcomes of autologous stem cell transplantation in patients with FL from 1991 to 2003. Seventeen men and seven women (n=24) of median age 47.5 years (range 28-64 years) were treated. Three patients with high-risk FL were in first remission. Twenty-one patients were salvaged after relapse with second-line chemotherapy. Of these, 14 were in CR at the time of transplantation, and seven patients were transplanted with active disease. Bone marrow was used in six patients as the source of stem cells prior to 1995 and peripheral blood stem cells were used in 18 patients. Twenty-three of 24 patients engrafted (96%). Median time for neutrophil recovery was 11.5 days (range 9-35 days) and 15 days (range 10-40 days) for platelets. Median duration of follow-up was 6 years (range 7 months-8 years). Of the 24 patients, six have died-with one patient death due to transplant-related pulmonary complications. Overall survival (OS) and disease-free survival (DFS) of all evaluable patients were 71.6 and 40%, respectively. Median duration of response was 4.3 years. OS and DFS in patients transplanted in CR were 80 and 57%, respectively. For those transplanted with disease, a complete response was achieved in 43% of patients, with the OS and DFS of 57 and 19%, respectively. Disease status at transplantation was not a significant variable for survival (p>0.3). Three patients developed moderate to severe treatment-related toxicity, two with grade III mucositis and one with life-threatening infection. When these results are compared with historical controls or patients treated with other modalities, autologous stem cell transplantation appears to be providing the longest disease-free survival and best duration of response.

Concurrent administration of high-dose rituximab before and after autologous stem-cell transplantation for relapsed aggressive B-cell non-Hodgkin's lymphomas

PURPOSE

We investigated the efficacy and safety of administering high-dose rituximab (HD-R) in combination with high-dose carmustine, cytarabine, etoposide, and melphalan chemotherapy and autologous stem-cell transplantation (SCT) in patients with recurrent B-cell aggressive non-Hodgkin's lymphoma (NHL).

PATIENTS AND METHODS

Sixty-seven consecutive patients were treated. Rituximab was administered during stem-cell mobilization (1 day before chemotherapy at 375 mg/m(2) and 7 days after chemotherapy at 1,000 mg/m(2)), together with granulocyte colony-stimulating factor 10 mug/kg and granulocyte-macrophage colony-stimulating factor 250 microg/m(2) administered subcutaneously daily. HD-R of 1,000 mg/m(2) was administered again days 1 and 8 after transplantation. The results of this treatment were retrospectively compared with those of a historical control group receiving the same preparative regimen without rituximab.

RESULTS

With a median follow-up time for the study group of 20 months, the overall survival rate at 2-years was 80% (95% CI, 65% to 89%) for the study group and 53% (95% CI, 34% to 69%) for the control group (P = .002). Disease-free survival was 67% (95% CI, 51% to 79%) for the study group and 43% (95% CI, 26% to 60%) for the control group (P = .004). The median time to recovery of absolute neutrophil count to >/= 500 cells/microL was 11 days (range, 8 to 37 days) for the rituximab group and 10 days (range, 8 to 17 days) for the matched control group (P = .001). However, infections were not significantly increased in patients treated with rituximab.

CONCLUSION

The results of this study suggest that using HD-R and autologous SCT is a feasible and promising treatment for patients with B-cell aggressive NHL.

Effects of Pretransplantation Treatment With Rituximab on Outcomes of Autologous Stem-Cell Transplantation for Non-Hodgkin's Lymphoma

Purpose

To analyze the effects of preautografting treatment with rituximab (R) on stem-cell mobilization, post-transplantation complications, engraftment, disease-free survival, and overall survival in patients with non-Hodgkin's lymphoma (NHL).

Patients and Methods

Single-institution retrospective comparative outcome analysis in a cohort of 273 relapsed chemosensitive NHL patients of whom 127 (47%) received R pretransplantation.

Results

R was administered a median of 3 months before autologous transplantation. When compared to the nonrituximab group, R patients were older (56 v 50 years; P < .001), and had delays in post-transplantation platelets recovery (39 v 27 days; P = .001). Pretransplantation R did not affect stem-cell mobilization, post-transplantation early complications, duration of hospitalization, or mortality rates at days 30 and 100. In contrast to patients with low-grade NHL, both disease-free and overall survival rates were significantly better when R was included in the pretransplantation salvage therapy for patients with intermediate-grade NHL.

Conclusion

In this large, single-center retrospective analysis, pretransplantation treatment with R was associated with improved survival in patients with intermediate-grade NHL, at the price, however, of a delay in platelet engraftment.

High-dose treosulfan in patients with relapsed or refractory high-grade lymphoma receiving tandem autologous blood stem cell transplantation

This phase I/II study evaluated high-dose treosulfan in patients with high-grade lymphoma. In all, 21 patients (median age 51, 25-60 years) with primary refractory disease (n=3) or early (n=11) or late (n=7) relapse received DexaBEAM and one course etoposide for cytoreduction and PBPC mobilization. Subsequently, 16 patients received 30 g/m2 treosulfan and 140 mg/m2 melphalan, followed by autologous transplantation. Nine patients received a 2nd high-dose treatment (HDT) with 30 g/m2 treosulfan and 750 mg/m2 thiotepa. Recovery time to >1/nl leukocytes and >25/nl thrombocytes was 8.9 (range 8-11) and 11.9 (8-16) days after 1st and 9.6 (7-13) and 13 (9-19) days after 2nd HDT. Reversible grade 3 or 4 nonhematologic toxicities included mucositis (n=7), infection (n=7) and one episode of re-entry tachycardia. Two treatment-related deaths occurred after 2nd HDT. Since three dose-limiting toxicities occurred among nine patients receiving tandem HDT, 30 g/m2 of treosulfan was considered MTD in this setting. Patients with late compared to early relapse or refractory disease had a higher probability of CR (6/7 vs 3/14 patients, P=0.017) and overall survival (71 vs 21%, P<0.05, 24-49 months follow-up). In conclusion, high-dose treosulfan as major therapy component induces sustained complete remissions in relapsed high-grade lymphoma with acceptable toxicity.