Long-term results favor allogeneic over autologous hematopoietic stem cell transplantation in patients with refractory or recurrent indolent non-Hodgkin's lymphoma

Moving T-Cell Therapies into the Standard of Care for Patients with Relapsed or Refractory Follicular Lymphoma: A Review

Patients with follicular lymphoma, an indolent form of non-Hodgkin lymphoma, typically experience multiple relapses over their disease course. Periods of remission become progressively shorter with worse clinical outcomes after each subsequent line of therapy. Currently, no clear standard of care/preferred treatment approach exists for patients with relapsed or refractory follicular lymphoma. As novel agents continue to emerge for treatment in the third-line setting, guidance is needed for selecting the most appropriate therapy for each patient. Several classes of targeted therapeutic agents, including monoclonal antibodies, phosphoinositide 3-kinase inhibitors, enhancer of zeste homolog 2 inhibitors, chimeric antigen receptor (CAR) T-cell therapies, and bispecific antibodies, have been approved by regulatory authorities based on clinical benefit in patients with relapsed or refractory follicular lymphoma. Additionally, antibody-drug conjugates and other immunocellular therapies are being evaluated in this setting. Effective integration of CAR-T cell therapy into the treatment paradigm after two or more prior therapies requires appropriate patient selection based on transformation status following a rebiopsy; a risk evaluation based on age, fitness, and remission length; and eligibility for CAR-T cell therapy. Consideration of important logistical factors (e.g., proximity to the treatment center and caregiver support during key periods of CAR-T cell therapy) is also critical. Overall, an individualized treatment plan that considers patient-related factors (e.g., age, disease status, tumor burden, comorbidities) and prior treatment types is recommended for patients with relapsed or refractory follicular lymphoma. Future analyses of real-world data and a better understanding of mechanisms of relapse are needed to further refine patient selection and identify optimal sequencing of therapies in this setting.

Nine-Year Follow-up of Patients with Relapsed Follicular Lymphoma after Nonmyeloablative Allogeneic Stem Cell Transplant and Autologous Transplant

PURPOSE

To compare outcomes between patients with relapsed follicular lymphoma who received a nonmyeloablative allogeneic stem cell transplant (alloSCT) and those who received an autologous transplant (autoSCT).

PATIENTS AND METHODS

We evaluated 194 patients with follicular lymphoma who received an alloSCT (n = 98) or autoSCT (n = 96) at MD Anderson Cancer Center (Houston, TX). The transplant type used was based on donor availability and by Medicare reimbursement guidelines. Patients who received an alloSCT were enrolled in four consecutive trials in which they received fludarabine, cyclophosphamide (or bendamustine), and rituximab conditioning. autoSCT patients received R-BEAM (rituximab, carmustine, etoposide, cytarabine, and melphalan).

RESULTS

The median follow-up of survivors was 108 months for the alloSCT group and 102 months for the autoSCT group. Overall survival was significantly better for patients who received an alloSCT compared with those who received an autoSCT (62% vs. 46%; P = 0.048). Similarly, progression-free survival rates were 52% in patients who received an alloSCT and 31% in those who received an autoSCT (P < 0.001), and the 8-year relapse rates were 11% and 43%, respectively (P < 0.0001). Only three patients in the alloSCT group relapsed beyond 3.5 years. In the alloSCT group, the rates for grade 2 to 4 acute graft-versus-host disease (GVHD), grade 3 to 4 acute GVHD, and extensive chronic GVHD were 22%, 9%, and 38%, respectively. In the autoSCT group, the 8-year incidence of secondary myelodysplasia was 11%. Nonrelapse mortality was similar between the two groups (15% vs. 11% at 8 years; P = 0.27).

CONCLUSIONS

This study shows that alloSCT is curative and confers superior survival compared with autoSCT in patients with follicular lymphoma.

Comparison of Survival Between Autologous and Allogeneic Stem Cell Transplantation in Patients with Relapsed or Refractory B-Cell Non-Hodgkin Lymphoma: A Meta-Analysis

This study aimed to compare the efficacy of allogeneic stem cell transplantation (allo-SCT) versus autologous SCT (auto-SCT) in patients with relapsed or refractory B-cell non-Hodgkin lymphoma (B-NHL). Medline, CENTRAL, and EMBASE databases through December 31, 2019 were searched. The primary endpoints were overall survival (OS) and progression-free survival (PFS) rates. The secondary outcomes include transplant-related mortality (TRM), event-free survival, relapse/or progression, and nonrelapse mortality (NRM). The 18 retrospective studies enrolled 8,058 B-NHL patients (allo-SCT = 1,204; auto-SCT = 6,854). The OS was significantly higher in patients receiving auto-SCT than allo-SCT (pooled odds ratio [OR]: 1.69, 95% confidence interval [CI]: 1.29 to 2.22, P < 0.001), but no significant difference was found in PFS (pooled OR: 0.98, 95% CI: 0.69 to 1.38, P = 0.891). Auto-SCT patients also had lower TRM and NRM (TRM: OR = 0.23, P < 0.001; NRM: OR = 0.16, P < 0.001), but higher relapse or progression rate (OR = 2.37, P < 0.001) than allo-SCT patients. Subgroup analysis performed for different grades and subtypes of B-NHL showed higher OS in auto-SCT patients with high-grade B-NHL and diffused large B-cell lymphoma (DLBCL). There was, nevertheless, higher PFS in allo-SCT patients with low-grade B-NHL and follicular lymphoma (FL), and lower PFS in allo-SCT patients with DLBCL than their auto-SCT counterparts. In conclusion, the meta-analysis demonstrated that relapsed or refractory B-NHL patients who received auto-SCT have improved OS than those treated with allo-SCT, especially among those with DLBCL, but lower PFS among those with FL. However, the study is limited by a lack of randomized trials, patients’ heterogeneity, and possible selection bias.

Allogeneic Stem Cell Transplantation and Chimeric Antigen Receptor (CAR) T-Cell Therapy for the Treatment of Non-Hodgkin Lymphoma

Despite the myriad of available treatments, a substantial subset of patients with non-Hodgkin lymphoma are not able to achieve a prolonged disease-free interval with conventional chemotherapy or targeted agents. For these patients, hematopoietic stem cell transplantation remains an option for consolidative or curative treatment. Additionally, chimeric antigen receptor T-cell therapy has emerged for patients with relapsed/refractory B-cell lymphomas. Published studies vary widely in their selected approach to transplant and cellular therapies. This review summarizes available data related to allogeneic hematopoietic stem cell transplantation and chimeric antigen receptor T-cell therapy for the treatment of non-Hodgkin lymphomas.

3D in vitro microvascular model-based lymphoma model

Diffuse large B-cell lymphoma (DLBCL) is a particularly aggressive cancer, impacting the lives of approximately 20,000 people annually in the United States. Elucidating cellular interactions that occur within the microenvironment of DLBCL tumors is crucial to the successful development of therapeutic strategies for this condition. As the in vivo microenvironment of DLBCL is quite complex and variable, in vitro platforms that can sufficiently recapitulate these multifaceted cellular interactions without introducing the complexities of in vivo systems are vital for understanding the pathophysiology of this disease. In this chapter, we present a method for fabrication and development of an in vitro DLBCL-on-chip model in which a fully vascularized, perfusable, microfluidic traverses a DLBCL tumor cell-laden hydrogel that successfully recapitulates hallmark attributes and cellular interaction that occur within the DLBCL tumor microenvironment. As this microfluidic approach makes use of common laboratory items and does not require traditional photolithography to fabricate, this system represents a vital tool that can unlock previously inaccessible research areas of the DLBCL tumor microenvironment to researchers across numerous fields.

[Allogeneic haematopoietic cell transplantation for indolent lymphomas: Guidelines from the Francophone Society Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)]

Despite great improvements in the outcome of patients with lymphoma, some may still relapse or present with primary refractory disease. In these situations, allogeneic hematopoietic cell transplantation is a potentially curative option, this is true particularly the case of relapse after autologous stem cell transplantation. Recently, novel agents such as anti-PD1 and BTK inhibitors have started to challenge the use of allogeneic hematopoietic cell transplantation for relapsed or refractory lymphoma. During the 2016 annual workshop of the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC), we performed a comprehensive review of the literature published in the last 10 years and established guidelines to clarify the indications and transplant modalities in this setting. This paper specifically reports on our conclusions regarding indolent lymphomas, mainly follicular lymphoma and chronic lymphocytic leukemia.

3D microvascular model recapitulates the diffuse large B-cell lymphoma tumor microenvironment in vitro

Diffuse large B-cell lymphoma (DLBCL) is an aggressive cancer that affects ∼22 000 people in the United States yearly. Understanding the complex cellular interactions of the tumor microenvironment is critical to the success and development of DLBCL treatment strategies. In vitro platforms that successfully model the complex tumor microenvironment without introducing the variability of in vivo systems are vital for understanding these interactions. To date, no such in vitro model exists that can accurately recapitulate the interactions that occur between immune cells, cancer cells, and endothelial cells in the tumor microenvironment of DLBCL. To that end, we developed a lymphoma-on-chip model consisting of a hydrogel based tumor model traversed by a vascularized, perfusable, round microchannel that successfully recapitulates key complexities and interactions of the in vivo tumor microenvironment in vitro. We have shown that the perfusion capabilities of this technique allow us to study targeted treatment strategies, as well as to model the diffusion of infused reagents spatiotemporally. Furthermore, this model employs a novel fabrication technique that utilizes common laboratory materials, and allows for the microfabrication of multiplex microvascular environments without the need for advanced microfabrication facilities. Through our facile microfabrication process, we are able to achieve micro vessels within a tumor model that are highly reliable and precise over the length of the vessel. Overall, we have developed a tool that enables researchers from many diverse disciplines to study previously inaccessible aspects of the DLBCL tumor microenvironment, with profound implications for drug delivery and design.

Outcome Comparison of Allogeneic versus Autologous Stem Cell Transplantation in Transformed Low-Grade Lymphoid Malignancies: A Systematic Review and Pooled Analysis of Comparative Studies

BACKGROUND

Some patients with low-grade lymphoid malignancies develop transformed disease, requiring stem cell transplantation (SCT). SCT outcomes in transformed low-grade lymphoid malignancies may differ from those of nontransformed disease or other aggressive non-Hodgkin lymphomas. We conducted a pooled analysis of the clinical outcomes of allogeneic versus high-dose therapy (HDT) with autologous SCT in adult patients with transformed low-grade lymphoid malignancies.

METHODS

A PubMed, EMBASE, and Cochrane search yielded 4 comparative studies reporting allogeneic versus HDT with autologous SCT outcomes in adults (age ≥18) with transformed low-grade lymphoid malignancies, including follicular, chronic/small lymphocytic, and marginal zone lymphoma. Risk ratio (RR) and 95% CI were calculated using random-effects models.

RESULTS

Rates for overall survival (OS) were 51.0 versus 69.5% (RR = 1.55, 95% CI 1.19-2.02, p = 0.001), rates of relapse were 37.3 versus 35.3% (RR = 1.04, 95% CI 0.70-1.55, p = 0.84), and rates of transplant-related mortality (TRM) were 33.3 versus 7.2% (RR = 4.52, 95% CI 2.75-7.43, p < 0.00001) for allogeneic versus autologous SCT. Previous rituximab treatment, reduced intensity conditioning regimen prior to SCT, or original pathology had no prognostic impact.

CONCLUSION

HDT followed by autologous SCT was associated with lower TRM and a better OS, but there was no difference in relapse versus allogeneic SCT. Autologous SCT may be the better therapeutic option, considering the second chance of allogeneic SCT in the case of relapse.

Reappraising the timing of transplant for indolent non-Hodgkin lymphomas

INTRODUCTION

Indolent non-Hodgkin lymphomas (iNHL) remain incurable with standard approaches. The timing of autologous stem cell transplant (ASCT) is changing following the introduction of new drugs that can potentially defer the transplant, improved reduced intensity conditioning (RIC) and haploidentical allogeneic SCT (allo-SCT).

AREAS COVERED

The most relevant aspects concerning the role of hematopoietic stem cell transplantation in the management of iNHL are discussed. Literature search methodology included examination of PubMed index and meeting presentations. Expert commentary: ASCT is not currently employed as consolidation in first-line, being reserved to patients with refractory/relapsed disease. The curative potential of graft-versus-lymphoma (GVL) after RIC allo-SCT could be particularly beneficial in patients with iNHL relapsing after ASCT. This scenario could be modified in the near future by better definition of high-risk patients at diagnosis, by the improvement of minimal residual disease (MRD) evaluation and by the introduction of new drugs in the therapeutic algorithm.

Long-term survival outcomes of reduced-intensity allogeneic or autologous transplantation in relapsed grade 3 follicular lymphoma

Grade 3 follicular lymphoma (FL) has aggressive clinical behavior. To evaluate the optimal first transplantation approach in relapsed/refractory grade 3 FL patients, we compared the long-term outcomes after allogeneic (allo-) vs autologous hematopoietic cell transplantation (auto-HCT) in the rituximab era. A total of 197 patients undergoing first reduced-intensity conditioning (RIC) allo-HCT or first auto-HCT during 2000-2012 were included. Rituximab-naive patients were excluded. Allo-HCT recipients were younger, more heavily pretreated and had a longer interval between diagnosis and HCT. The 5-year probabilities of non-relapse mortality (NRM), relapse/progression, PFS and overall survival (OS) for auto-HCT vs allo-HCT groups were 4% vs 27% (P<0.001), 61% vs 20% (P<0.001), 36% vs 51% (P=0.07) and 59% vs 54% (P=0.7), respectively. On multivariate analysis, auto-HCT was associated with reduced risk of NRM (relative risk (RR)=0.20; P=0.001). Within the first 11 months post HCT, auto- and allo-HCT had similar risks of relapse/progression and PFS. Beyond 11 months, auto-HCT was associated with higher risk of relapse/progression (RR=21.3; P=0.003) and inferior PFS (RR=3.2; P=0.005). In the first 24 months post HCT, auto-HCT was associated with improved OS (RR=0.42; P=0.005), but in long-time survivors (beyond 24 months) it was associated with inferior OS (RR=3.6; P=0.04). RIC allo-HCT as the first transplant approach can provide improved PFS and OS, in long-term survivors.

Reduced-Intensity Allografting as First Transplantation Approach in Relapsed/Refractory Grades One and Two Follicular Lymphoma Provides Improved Outcomes in Long-Term Survivors

This study was conducted to compare long-term outcomes in patients with refractory/relapsed grades 1 and 2 follicular lymphoma (FL) after allogeneic (allo) versus autologous (auto) hematopoietic cell transplantation (HCT) in the rituximab era. Adult patients with relapsed/refractory grades 1 and 2 FL undergoing first reduced-intensity allo-HCT or first autograft during 2000 to 2012 were evaluated. A total of 518 rituximab-treated patients were included. Allo-HCT patients were younger and more heavily pretreated, and more patients had advanced stage and chemoresistant disease. The 5-year adjusted probabilities, comparing auto-HCT versus allo-HCT groups for nonrelapse mortality (NRM) were 5% versus 26% (P < .0001); relapse/progression: 54% versus 20% (P < .0001); progression-free survival (PFS): 41% versus 58% (P < .001), and overall survival (OS): 74% versus 66% (P = .05). Auto-HCT was associated with a higher risk of relapse/progression beyond 5 months after HCT (relative risk [RR], 4.4; P < .0001) and worse PFS (RR, 2.9; P < .0001) beyond 11 months after HCT. In the first 24 months after HCT, auto-HCT was associated with improved OS (RR, .41; P < .0001), but beyond 24 months, it was associated with inferior OS (RR, 2.2; P = .006). A landmark analysis of patients alive and progression-free at 2 years after HCT confirmed these observations, showing no difference in further NRM between both groups, but there was significantly higher risk of relapse/progression (RR, 7.3; P < .0001) and inferior PFS (RR, 3.2; P < .0001) and OS (RR, 2.1; P = .04) after auto-HCT. The 10-year cumulative incidences of second hematological malignancies after allo-HCT and auto-HCT were 0% and 7%, respectively. Auto-HCT and reduced-intensity-conditioned allo-HCT as first transplantation approach can provide durable disease control in grades 1 and 2 FL patients. Continued disease relapse risk after auto-HCT translates into improved PFS and OS after allo-HCT in long-term survivors.

High-dose chemotherapy followed by autologous and allogeneic hematopoietic stem cell transplantation in patients with follicular non-Hodgkin’s lymphoma in the rituximab era

High-dose chemotherapy in lymphomas, and mainly non-Hodgkin’s lymphomas, has been advancing since the 1970s. This therapeutic strategy is based on the supposed existence of a dose-response curve for cytotoxic agents. However, the available data are contradictory, so high-dose chemotherapy cannot be guaranteed as consolidation treatment for first-remission follicular lymphoma or diffuse large cell lymphoma. The objective of this paper is to review the current knowledge about high-dose chemotherapy followed by hematopoietic stem cell transplantation in follicular non-Hodgkin’s lymphoma. The published studies on follicular lymphoma after first remission, recurrent follicular lymphoma, and transformed follicular ­lymphoma were assessed together with the data available on diffuse large cell lymphoma. During analysis of the studies, difficulties were encountered in comparing studies due to the heterogeneous nature of the data. High-dose chemotherapy as consolidation treatment after first remission or in recurrent or refractory disease was also analyzed.

A rare but potentially fatal cause of diarrhoea and weight loss: enteropathy-associated T-cell lymphoma

Enteropathy-associated T-cell lymphoma (EATL) is a rare but potentially fatal cause of diarrhoea and weight loss. EATL commonly presents with abdominal pain, diarrhoea and weight loss, but can also present with complications such as bowel obstruction and perforation. It is a tumour of intraepithelial lymphocytes that occurs in a relatively young population. It is the most common neoplastic complication of coeliac disease, but can occur with no prior diagnosis of coeliac disease. This case demonstrates the difficulties that can be faced in diagnosing this disorder, particularly when there is no preceding history of coeliac disease. Early diagnosis is of utmost importance in order to start treatment before the effects of malnutrition increase the risk of complications from chemotherapy. Hence awareness of the condition among general medical physicians, to whom it will often present first, is essential. However, even with prompt diagnosis, outcomes for this condition remain poor.

Long term follow-up of BEAM-autologous and BEAM-alemtuzumab allogeneic stem cell transplantation in relapsed advanced stage follicular lymphoma

This is an analysis in 171 patients comparing BEAM-Auto and BEAM-Allo (alemtuzumab)-hematopoietic stem cell transplantation in relapsed follicular lymphoma. BEAM-Allo group had a lower 10 years cumulative incidence of relapse(31.4% vs 55.1%, p=0.042), a trend to a plateau in survival but no statistical differences in OS or DFS, and a TRM of 24%. When transplanted in CR BEAM-Allo patients had better OS and DFS. Incidence of acute and chronic GVHD was 16.6% and 22%. 29% of BEAM-Allo patients received DLI (all but two remain in CR and alive). Our data supports Allo-HSCT as a potential curative treatment for selected patients with FL.

Is there a role for autotransplants in patients with follicular lymphoma in the rituximab era?

Patients with low grad follicular lymphoma were shown to be able to achieve long-term disease-free survival when transplanted after relapse in the era before the wide spread use of rituximab. It appears that the availability of rituximab has not diminished the value of transplantation (i.e., either autologous or allogeneic) in the care of these patients. A similar overall survival and less treatment related toxicity make autologous transplantation the better choice for most patients transplanted at first treatment failure.

Long-Term Results of Fludarabine/Melphalan as a Reduced-Intensity Conditioning Regimen in Mantle Cell Lymphoma: The GELTAMO Experience

BACKGROUND

We herein report the long-term results of an allogeneic reduced-intensity conditioning (allo-RIC) protocol used in 21 consecutive patients (16 males, median age 56 years, 71% in complete remission) diagnosed with mantle cell lymphoma (MCL).

METHODS

The allo-RIC consisted of fludarabine plus melphalan and peripheral blood hematopoietic stem cells (PBSCs) from human leukocyte antigen (HLA)-identical siblings were used in all cases. Median CD34+ infused cells was 5.8 times 10(6)/kg. All patients engrafted promptly.

RESULTS

Early toxicity included mild/moderate mucositis (43%), febrile neutropenia (33%) and bacterial infections (19%). With a median follow up of 48 months, four deaths were reported, all due to infections and/or graft-versus-host disease (GVHD), yielding a 3-year cumulative incidence of nonrelapse mortality of 19.5%. Grade III-IV acute GVHD occurred in 15% and chronic GVHD in 78%, being extensive in 39%. The 5-year progression-free survival (PFS) and overall survival (OS) were both 80% (95% CI: 63-97%). Age was the only possible prognostic factor for OS, which was 43% for those aged more than 60 years and 100% for those younger (p < 0.001).

CONCLUSIONS

Our data confirm that allo-RIC offers a low toxicity profile and a chance for prolonged long-term disease-free survival in MCL, particularly in younger patients.

Nonmyeloablative allogeneic stem cell transplantation for non-hodgkin lymphoma

Non-Hodgkin lymphomas constitute a heterogeneous group of hematologic malignancies with varying aggressiveness and many therapeutic options. Nonmyeloablative (NMA) conditioning has been the cornerstone of allogeneic adoptive immunotherapy for these diseases. This approach utilizes a reduced intensity preparative regimen to achieve engraftment with little toxicity. This allows for development of the immune graft-versus-lymphoma effect. Results depend on the histologic type of lymphoma, prognostic factors, patient characteristics, and chemosensitivity. For follicular lymphomas, NMA transplants are highly effective in patients with refractory or recurrent disease after the best chemoimmunotherapy available and who have a matched sibling or unrelated donor. In mantle cell lymphoma, autologous stem cell transplants are generally ineffective for patients with recurrent disease; we reported 6-year actuarial progression-free survival rate of 46%, using NMA allogeneic transplants. The indications of NMA transplants for diffuse large B-cell lymphoma and T-cell lymphomas are controversial; success has been reported in selected high-risk patients and those relapsing after an autologous transplantation who have chemosensitive disease. Considerations for the conditioning regimen, donor source, graft-versus-host disease prophylaxis, donor lymphocyte infusion, and relapse prevention methods are reviewed.

Changing role of stem cell transplantation in follicular lymphoma

Patients with advanced follicular lymphoma (FL) have numerous treatment options, including observation, radiotherapy, single-agent or combination chemotherapy, mAbs, and radioimmunoconjugates. These therapies can extend progression-free survival but none can provide a cure. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains the only curable therapy for FL, with the field shifting more toward the use of reduced-intensity conditioning regimens because of the lower associated nonrelapse mortality compared with myeloablative regimens. However, GVHD and infection are still problematic in the allo-HSCT population. Autologous HSCT (auto-HSCT) confers high response rates and prolongs progression-free survival in relapsed patients who are chemosensitive, and an increasing amount of data suggest that auto-HSCT may be curative if offered to relapsed patients who are not heavily pretreated. Auto-HSCT has no role as consolidation therapy for patients in first remission based on the results from 3 large randomized trials. Novel conditioning regimens with radioimmunoconjugates have been used in both auto-HSCT and allo-HSCT regimens and results have shown efficacy even in chemorefractory patients. Therefore, with the exception of patients in first remission, the optimal timing for HSCT remains controversial. However, the outcomes seen after auto-HSCT and allo-HSCT continue to improve, and HSCT represents a treatment modality that should be considered in all FL patients, especially while their disease remains chemoresponsive.

Nonmyeloablative allogeneic transplantation with or without 90yttrium ibritumomab tiuxetan is potentially curative for relapsed follicular lymphoma: 12-year results

In 2008, we reported favorable 5-year outcomes of nonmyeloablative allogeneic stem cell transplantation after fludarabine, cyclophosphamide, rituximab (FCR) conditioning for relapsed and chemosensitive follicular lymphoma. However, innovative strategies were still needed to treat patients with chemorefractory disease. We therefore subsequently performed a trial in which (90)Y-ibritumomab tiuxetan (0.4 mCi/kg) was added to the fludarabine, cyclophosphamide conditioning regimen ((90)YFC). Here, we report updated results of the FCR trial and outcomes after (90)YFC. For the FCR group (N = 47), since the last update, one patient developed recurrent disease. With a median follow-up of 107 months (range, 72-142 months), the 11-year overall survival and progression-free survival rates were 78%, and 72%, respectively. For the (90)YFC group (N = 26), more patients had chemorefractory disease than did those in the FCR group (38% and 0%, P < .001). With a median follow-up of 33 months (range,17-94 months), the 3-year progression-free survival rates for patients with chemorefractory and chemosensitive disease were 80% and 87%, respectively (P = .7). The low frequency of relapse observed after a long follow-up interval of 9 years in the FCR group suggests that these patients are cured of their disease. The addition of (90)Y to the conditioning regimen appears to be effective in patients with chemorefractory disease. This trial was registered at www.clinicaltrials.gov as NCT00048737.

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.

Allogeneic stem cell transplantation in follicular lymphoma

Myeloablative allogeneic transplantation in follicular lymphoma has been found to be particularly effective in patients with relapsed disease and an inadequate bone marrow reserve or massive bone marrow involvement. Allogeneic transplantation carries the promise of long-term disease control by graft-versus-lymphoma immunity but is associated with a 30%-40% risk of transplant-related mortality. Nonmyeloablative stem cell transplantation exploits the graft-versus-lymphoma effect without the attendant toxicity of myeloablative conditioning. The results of several recent reports suggest that it has a high likelihood of resulting in long-term disease-free survival in patients up to 70 years of age with a good performance status, chemotherapy-sensitive disease, and HLA-matched sibling donors. At The University of Texas MD Anderson Cancer Center, the standard NST conditioning regimen for patients with follicular lymphoma is fludarabine, cyclophosphamide, and rituximab. This regimen results in a transplantation-related mortality rate of 10%, and 85% of patients are alive without disease at 8 years. In this article, we discuss the current issues in NST for follicular lymphoma, including chemosensitivity, conditioning intensity, graft-versus-host disease, donor lymphocyte infusion's role, and ongoing strategies to treat refractory disease.

Adoptive T-cell therapy for B-cell malignancies

The success of allogeneic hematopoietic cell transplantation (HCT) for B-cell malignancies is evidence that these tumors can be eliminated by T lymphocytes. This has encouraged the development of specific adoptive T-cell therapy, both for augmenting the anti-tumor effect of HCT and for patients not undergoing HCT. T cells that are capable of recognizing antigens expressed on malignant B cells may be recruited from the endogenous repertoire or engineered to express tumor-targeting receptors. Critical insights into the qualities of T cells that enable their persistence and function in vivo have been derived, and obstacles to effective T-cell-mediated tumor eradication are being elucidated. These advances provide the tools to translate adoptive T-cell transfer into reliable clinical therapies.

Haploidentical hematopoietic stem-cell transplantation for non-Hodgkin lymphoma with bone marrow involvement

Here, we report the preliminary results of haploidentical hematopoietic stem cell transplantation (Haplo-HSCT) with granulocyte-colony-stimulating factor (G-CSF) mobilized bone marrow grafts without T-cell depletion for 10 patients with refractory non-Hodgkin lymphoma accompanied by bone marrow involvement. Eight patients received a conditioning regimen consisting of high-doses of cytarabine and cyclophosphamide with total body irradiation, whereas two cases were preconditioned with busulfan, thiotepa, and cyclophosphamide. All patients had rapid hematopoietic engraftment with the mean time for neutrophil and platelet recovery being 16.6 days and 19.2 days, respectively. Three cases died within 6 months after transplantation from severe acute graft-versus-host disease, fungal infection, or relapse. The others are currently alive in complete remission at a median follow-up of 60.71 months (range: 44-81 months). The results here suggest that haplo-HSCT might provide an opportunity of myeloablative therapy for refractory lymphoma with marrow infiltration.

Autologous versus reduced-intensity allogeneic hematopoietic cell transplantation for patients with chemosensitive follicular non-Hodgkin lymphoma beyond first complete response or first partial response

Patients with follicular lymphoma (FL) typically experience an indolent course; however, the disease is rarely curable with conventional chemotherapy. Autologous hematopoietic cell transplantation (HCT) can extend progression-free survival (PFS) and overall survival (OS), but relapse is the primary cause of failure. Allogeneic HCT confers lower relapse rates due to a graft-versus-lymphoma effect. Reduced-intensity conditioning (RIC) allows the performance of allogeneic HCT with lower toxicity. The Blood and Marrow Transplant Clinical Trials Network conducted a prospective multicenter trial comparing these two strategies in patients with relapsed, chemotherapy-sensitive FL. Patients were assigned to a treatment arm based on the availability of an HLA-matched sibling donor (MSD). Those with an MSD underwent allogeneic HCT (n = 8) with the FCR preparative regimen (fludarabine, cyclophosphamide [Cy], rituximab [RTX]) and received tacrolimus and methotrexate for graft-versus-host disease (GVHD) prophylaxis. Those without an MSD (n = 22) underwent mobilization with Cy, RTX, and filgrastim and received a conditioning regimen of either CBV (Cy, carmustine, Etoposide [VP16]) or total body irradiation with Cy and VP16. Patients undergoing autologous HCT received 4 doses of weekly maintenance RTX (375 mg/m²) starting on day +42 post-HCT. Sixteen patients were in complete remission, 10 patients were in partial remission, and 1 patient had stable disease after salvage therapy and before HCT. Median follow-up was 36 months (range, 1-51 months). OS was 73% in autologous HCT versus 100% in allogeneic HCT, and PFS was 63% in autologous HCT versus 86% in allogeneic HCT. No patient had grade II-IV acute GVHD; two patients developed extensive chronic GVHD. Three autologous recipients died from nonrelapse causes. This trial closed early because of slow accrual. We show that the FCR regimen is well tolerated, and that both allogeneic and autologous HCT result in promising 3-year OS and PFS in patients with relapsed FL.

Role of transcription factors in cell replacement therapies for neurodegenerative conditions

Parkinson's disease is the second most common neurological condition, behind dementia, for which there is currently no cure. A promising curative treatment approach is cell replacement therapy, which involves the introduction of new dopaminergic cells into a degenerative Parkinson's disease brain. The future progression of this field into a clinically viable treatment option is reliant on generating replacement dopaminergic cells. Furthermore, as the ability of transplanted dopaminergic neurons to form connections with host tissue is dependent on where the cells are derived from, the replacement dopaminergic cells will need to be phenotypically similar to substantia nigra dopaminergic neurons. This article focuses on how developmental transcription factors have been utilized to assist the progression of stem cell therapies for Parkinson's disease. Key transcription factor-mediated stages of substantia nigra dopaminergic neuronal development is described in the belief that a comprehensive understanding of this specific dopaminergic differentiation pathway is necessary for the progression of successful cell therapies for Parkinson's disease.

Hematopoietic stem cell transplantation for the management of follicular lymphoma

Although much has been published on the application of autologous and allogeneic hematopoietic stem cell transplantation in patients with follicular lymphoma (FL), no uniform consensus exists among physicians on when to use this strategy. Three large randomized trials failed to show a survival benefit using autologous transplantation for FL patients in first complete remission. Similarly, many Phase II or registry-based studies have also failed to show a survival benefit with autologous transplantation in relapsed or refractory FL patients, although the progression-free survival seems to be prolonged in transplant recipients. Allogeneic stem cell transplantation can cure a subset of patients with FL, but high nonrelapse mortality and morbidity remain a concern. No consensus exists on what conditioning regimen should be used, or how the newer monoclonal antibodies should be incorporated into the transplant paradigm. Here we present a review of the role of autologous and allogeneic hematopoietic stem cell transplantation in patients with FL.

Enteropathy associated T-cell lymphoma and its precursor lesions

Enteropathy Associated T-cell Lymphoma (EATL) is an intestinal tumour of intra-epithelial lymphocytes. Based on morphology, immunohistochemistry and genetic profile EATL can be divided into two groups. EATL type I is a large cell lymphoma which is highly associated with Coeliac Disease (CD) and mostly presents with malabsorption, weight loss and CD-related symptoms. EATL type II consists of small to medium-sized cells and presents often with obstruction or perforation of the small bowel. This type of EATL has no known association with CD. When EATL has been diagnosed a thorough diagnostic work-up is needed. This work-up preferably includes video capsule enteroscopy (VCE), double-balloon enteroscopy (DBE), computed tomography (CT) combined with 18F-fluorodeoxyglucose positron emission tomography scan (18F-FDG-PET scan) if possible and magnetic resonance enteroclysis (MRE). Nowadays, most EATL patients are treated with chemotherapy mostly preceded by resection of the tumour and followed by stem cell transplantation. Despite these therapies outcome of EATL remains very poor with a 5-year survival of 8-20%. In order to improve survival prospective multicentre trials, studying new therapies are needed. The combination of chemotherapy, monoclonal antibodies and/or apoptosis inducing small molecules might be a potential treatment for EATL in the (nearby) future.

The role of cytotoxic therapy with hematopoietic stem cell transplantation in the treatment of follicular lymphoma: an evidence-based review

Clinical research examining the role of hematopoietic stem cell transplantation (SCT) in the therapy of follicular non-Hodgkin lymphoma in adults is presented and critically evaluated in this systematic evidence-based review. Specific criteria were used for searching the published literature and for grading the quality and strength of the evidence and the strength of the treatment recommendations. Treatment recommendations reached unanimously by a panel of follicular lymphoma experts are: (1) autologous SCT is recommended as salvage therapy based on pre-rituximab data, with a significant improvement in overall survival (OS) and progression-free (PFS) survival; (2) autologous SCT is not recommended as first-line treatment for most patients because of no significant improvement in OS; (3) autologous SCT is recommended for transformed follicular lymphoma patients; (4) reduced intensity conditioning before allogeneic SCT appears to be an acceptable alternative to myeloablative regimens; (5) an HLA-matched unrelated donor appears to be as effective an HLA-matched related donor for reduced intensity conditioning allogeneic SCT. There are insufficient data to make a recommendation on the use of autologous SCT after rituximab-based salvage therapy. Eleven areas of needed research in the treatment of follicular lymphoma with SCT were identified and are presented in the review.

Second-line age-adjusted International Prognostic Index in patients with advanced non-Hodgkin lymphoma after T-cell depleted allogeneic hematopoietic SCT

T-cell depleted allogeneic hematopoietic SCT (TCD-HSCT) have shown durable disease-free survival with a low risk of GVHD in patients with AML. We investigated this approach in 61 patients with primary refractory or relapsed non-Hodgkin lymphoma (NHL), who underwent TCD-HSCT from January 1992 through September 2004. Patients received myeloablative cytoreduction consisting of hyperfractionated total body irradiation, followed by either thiotepa and cyclophosphamide (45 patients) or thiotepa and fludarabine (16 patients). We determined the second-line age-adjusted International Prognostic Index score (sAAIPI) before transplant transplant. Median follow-up of surviving patients is 6 years. The 10-year OS and EFS were 50% and 43%, respectively. The relapse rate at 10 years was 21% in patients with chemosensitive disease and 52% in those with resistant disease at time of HSCT. Nine of the 18 patients who relapsed entered a subsequent CR. OS (P=0.01) correlated with the sAAIPI. The incidence of grades II-IV acute GVHD was 18%. We conclude that allogeneic TCD-HSCT can induce high rates of OS and EFS in advanced NHL with a low incidence of GVHD. Furthermore, the sAAIPI can predict outcomes and may be used to select the most appropriate patients for this type of transplant.

Lymphoma in adolescents and young adults

Non-Hodgkin (NHL) and Hodgkin (HL) lymphomas are represented prominently in the adolescent and young adult (AYA) population. These diseases represent 11% of total cancer diagnoses in children, 4% in those 40 years of age and older, and 13% in AYA (aged 15-39 years). Although age-adjusted incidence rates of NHL increase with age, the more aggressive lymphomas are seen more commonly in the younger population with a transition to low-grade, indolent subtypes as the population ages. Burkitt lymphoma, diffuse large B-cell lymphoma, lymphoblastic lymphoma, and anaplastic large cell lymphoma make up the most common subtypes in the AYA population, although within the subgroup age 30-39 years, follicular lymphoma becomes more prominent. As a result, much of the armamentarium in the treatment of aggressive NHL and HL in adults is based on data from pediatric clinical trials. There are obvious limitations to this approach. It is vital that we gain a more thorough understanding of the biology and therapeutic responsiveness of NHL and HL in the AYA population. Thus, we must leverage the large prospective and retrospective trials that have been completed to date and redirect our approaches to cancer care in this unique population. We review the epidemiological data on NHL and HL from the Surveillance, Epidemiology and End Results registries as a cornerstone for a comparative analysis of therapeutic outcomes available in this population.

Controversies in the treatment of lymphoma with autologous transplantation

High-dose therapy and autologous stem cell transplant (HDT-ASCT) is the standard of care for relapsed and refractory diffuse large B cell lymphoma and Hodgkin's lymphoma; however, the role for HDT-ASCT in the treatment of follicular lymphoma (FL), mantle cell lymphoma (MCL), and peripheral T cell lymphoma (PTCL) is controversial. In FL, phase II and randomized data support the use of HDT-ASCT in the relapsed setting and incorporation of rituximab into mobilization regimens and post-transplant maintenance appears to prolong remission durations. Allogeneic stem cell transplant remains the only curative treatment option and is appropriate for patients with high bone marrow disease burdens and refractory disease. In MCL, HDT-ASCT is most often administered up front, and phase II studies using intense immunochemotherapy followed by HDT-ASCT in first complete response (CR) have shown the most impressive outcomes. Complicating the situation, however, are data supporting up-front intensive immunochemotherapy without HDT-ASCT consolidation as well as a "watch and wait" strategy for selected patients. Finally, in PTCL, phase II data support treatment with HDT-ASCT in first CR, and it is rarely appropriate in the relapsed setting. Furthermore, disease status at the time of transplant likely impacts outcome; however, this needs to be evaluated further. Overall, HDT-ASCT is an important element of the treatment of relapsed FL and untreated MCL and PTCL; however, large prospective studies are needed to confirm its role and identify the most optimal induction, mobilization, and maintenance regimens for each disease.

Current status and future perspectives for yttrium-90 ((90)Y)-ibritumomab tiuxetan in stem cell transplantation for non-Hodgkin's lymphoma

Haematopoietic SCT is currently considered a therapeutic option mainly in relapsed or refractory non-Hodgkin's lymphoma (NHL) owing to high post-transplantation relapse rates and significant toxicity of conventional myeloablative conditioning for allogeneic SCT. Radiolabelled immunotherapy combines the benefits of monoclonal antibody targeting with therapeutic doses of radiation, and is a promising advance in the treatment of malignant lymphomas. It is now under investigation as a component of conditioning prior to SCT, with the aim of improving outcomes following SCT without increasing the toxicity of high-dose chemotherapy pre-transplant conditioning. An expert panel met at a European workshop in November 2006 to review the latest data on radiolabelled immunotherapy in the transplant setting, and its potential future directions, with a focus on (90)Y-ibritumomab tiuxetan. They reviewed data on the combination of standard/high/escalating dose (90)Y-ibritumomab tiuxetan with high-dose chemotherapy, and high/escalating dose (90)Y-ibritumomab tiuxetan as the sole myeloablative agent, prior to autologous SCT, and also (90)Y-ibritumomab tiuxetan as a component of reduced intensity conditioning prior to allogeneic SCT. The preliminary data are highly promising in terms of conditioning tolerability and patient outcomes following transplant; further phase II studies are now needed to consolidate these data and to investigate specific patient populations and NHL subtypes.

Disappointing outcome of autologous stem cell transplantation for enteropathy-associated T-cell lymphoma

BACKGROUND

Despite treatment, enteropathy-associated T-cell lymphoma has a very poor outcome. Chemotherapy can be complicated by small bowel perforation, gastrointestinal bleeding and development of enterocolic fistulae. Here we report on the feasibility, safety and efficacy of high-dose chemotherapy followed by autologous stem cell transplantation in patients with enteropathy-associated T-cell lymphoma (three upfront and one at relapse), with or without prior partial small bowel resection.

METHODS

Four patients [two males, two females, mean age 65 years (range 60-69 years)] received high-dose chemotherapy followed by autologous stem cell transplantation. Partial small bowel resection has been performed in three patients.

RESULTS

All four patients completed the mobilization and leucopheresis procedures successfully and subsequently received conditioning chemotherapy and transplantation. Engraftment occurred in all patients. No major non-haematological toxicity or transplantation-related mortality was observed. One patient has ongoing complete remission 32 months after transplantation. Three patients died from relapse within few months after autologous stem cell transplantation.

CONCLUSIONS

Autologous stem cell transplantation seems unsatisfactory for patients with enteropathy-associated T-cell lymphoma. More intensive conditioning and aggressive chemotherapy with/or without targeted immunotherapy as well as allogenous stem cell transplantation needs to be explored.

Allogeneic stem cell transplantation with T cell-depleted grafts for lymphoproliferative malignancies

In non-Hodgkin lymphoma allogeneic stem cell transplantation (SCT) can be curative, but with standard dose conditioning patients may have substantial morbidity and mortality from graft-versus-host disease (GVHD); for aggressive malignancies, reduced intensity conditioning may result in higher recurrence. Patients with advanced follicular lymphoma (n = 12), transformed B cell malignancy (n = 11), and non-CD30+T cell lymphomas (n = 17) responsive to chemotherapy who had an HLA-identical sibling were offered T cell depleted (CAMPATH-1 G or H antibodies) SCT. Conditioning was with ablative doses of chemotherapy or radiotherapy. Before SCT, patients with follicular lymphoma had a median of 3 treatment courses, and those with transformed B cell and those diagnosed with T cell non-Hodgkin lymphoma had 2 (range, 1-3). At SCT the median age was 46 years (range, 21-59 years) and the number of CD34+ cells infused was 2.85 x 10(6)/kg. All patients showed engraftment but 7 patients (17.5%) developed GVHD. In total 12 subjects expired of transplant-related causes (n = 6) or from disease recurrence. One-year transplant-related mortality was 15%. There was no difference in survival across diagnostic groups. At a median of 1051 days, 70% survived and 68% are without disease. By reducing the incidence and severity of GVHD, patients can tolerate myeloablative doses of chemotherapy satisfactorily. This has resulted in low treatment-related mortality and adequate protection from disease recurrence.

Follicular NHL: from antibodies and vaccines to graft-versus-lymphoma effects

Monoclonal antibody therapy with rituximab in combination with standard chemotherapy has improved the survival of patients with advanced-stage follicular lymphoma (FL). A series of next-generation anti-CD20 antibodies may be less immunogenic and have even greater antitumor activity through augmented interactions with host effector mechanisms responsible for tumor cell kill. Additional approaches with patient-specific immunoglobulin idiotype vaccines; novel monoclonal antibodies binding to biologically active cell-surface antigen are also demonstrating early clinical activity. Antibodies targeting radioisotopes, toxins or drugs are also slowly entering clinical trials and practice. Last, allogeneic stem cell transplantation following reduced-intensity conditioning provides graft-versus-tumor immune responses that may be able to control FL and allow this risky but potentially curative treatment option to older patents or those with comorbidities.

Role of allogeneic transplantation in low-grade lymphoma and chronic lymphocytic leukemia

PURPOSE OF REVIEW

Indolent lymphoproliferative disorders are incurable with conventional chemotherapy. Exploring the potential of allogeneic transplantation to eradicate disease has therefore been of interest for some time. This review reports on recent developments in this field to evaluate the current status of stem cell transplantation in the management of these conditions.

RECENT FINDINGS

Most recent studies examine the application of reduced intensity regimens in follicular non-Hodgkin's lymphoma and chronic lymphocytic leukemia. Interest is particularly focused on assessing the potency of the allogeneic graft-versus-malignancy effect, whether achieved by T cells infused at the time of transplant, or by the administration of exogenous donor lymphocytes at relapse or progression following transplant. Furthermore, the discovery of molecular/genetic factors that permit identification of patients with poor prognosis chronic lymphocytic leukemia has led to interest in identifying whether the allogeneic effect can overcome the impact of these factors.

SUMMARY

Encouraging evidence is accumulating for the efficacy of reduced intensity transplantation in indolent lymphoproliferative disorders. Allogeneic graft-versus-malignancy effects can be demonstrated and durable responses to donor lymphocytes are being reported. More follow-up is required, however, before the curative potential of allogeneic transplantation can be assessed. The appropriate timing of transplant and the choice of regimen remains unclear.

The role of hematopoietic cell transplantation for follicular non-Hodgkin's lymphoma

The overall survival with follicular lymphoma has not significantly changed over the last few decades, and there is no universal agreement as to the optimal first-line or subsequent therapy. High-dose chemotherapy with autologous hematopoietic cell transplantation (HCT) confers high response rates and improved progression-free survival in advanced-stage disease, and more recent data indicate a positive effect on overall survival. Initial results with myeloablative allogeneic HCT unequivocally demonstrated a reduction in relapse/progression compared with autologous HCT, but it is associated with prohibitive nonrelapse mortality. Nonmyeloablative or reduced-intensity regimens have substantially reduced up-front toxicity, and preliminary data seem highly encouraging with regard to efficacy. Novel strategies include the use of rituximab for in vivo purging and maintenance therapy. The incorporation of radioimmunoconjugates into conditioning regimens to deliver targeted radiotherapy also appears promising. This review summarizes current and new developments regarding the role of HCT for patients with follicular lymphoma.

Die Bedeutung der Stammzelltherapie in der Hämatologie und Onkologie

The transplantation of hematopoietic stem cells (HSCT) is an established part of the therapy of hematologic neoplasia and certain solid tumors. In the allogeneic approach hematopoietic stem cells are harvested from healthy donors, while in the autologous setting preparations originating from the patient himself are being used. Both therapies use high dose cytotoxic medication for the induction of higher remission rates in malignant diseases. While autologous HSCT rescues hematopoiesis after high dose chemotherapy, in allogeneic HSCT donor immune cells exert an additional allo-reactivity towards recipient tissue and residual malignant cells. Autologous HSCT is mainly used in relapsed malignant high-grade lymphoma. Allogeneic HSCT results in cure from acute leukemia with unfavorable prognosis in a high percentage of patients. Recent developments target the expansion of the donor pool for allogeneic stem cells and want to reduce chemotherapeutic toxicity of allogeneic transplantation with sustained anti-leukemia efficacy.

Transplantation strategies for patients with follicular lymphoma

PURPOSE OF REVIEW

This review summarizes the current status and new developments in autologous and allogeneic transplantation strategies for patients with follicular lymphoma including novel concepts of myeloablative radioimmunotherapy, allogeneic transplantation with dose-reduced conditioning, and in-vivo purging strategies using B-cell-specific antibodies.

RECENT FINDINGS

Substantial progress has been made in the clinical management of follicular lymphoma. Besides immunochemotherapeutic approaches combining the B-cell antibody rituximab with conventional chemotherapy regimens, myeloablative chemotherapy or radiochemotherapy supported by autologous peripheral blood stem cell transplantation has been shown to be a highly effective treatment for advanced-stage disease. Dose-reduced conditioning regimens followed by allogeneic transplantation have substantially reduced treatment-related mortality of this approach and ongoing studies are evaluating whether the therapeutic benefit outweighs morbidity and mortality of this potentially curative treatment. Emerging concepts include the use of rituximab for in-vivo purging before reinfusion of autologous stem cells or the application of myeloablative radioimmunotherapy as part of myeloablative consolidation.

SUMMARY

The data on myeloablative therapy followed by autologous stem cell transplantation or allogeneic transplantation are encouraging. Allogeneic transplantation with dose-reduced conditioning should be further evaluated within clinical trials, however, in particular for patients with relapsed or refractory lymphoma. Future prospective randomized clinical trials should reevaluate the role of autologous stem cell transplantation in the era of antibody-based therapy and define the role of radioimmunotherapy and of reduced-intensity allogeneic transplantation.

Graft-versus-lymphoma effects: clinical review, policy proposals, and immunobiology

The indubitable existence of a graft-versus-lymphoma (GVL) effect is difficult to prove directly. This article reviews the difficulties in interpreting the current literature in this field and, with a number of caveats, argues for the existence of a clinically meaningful GVL effect in follicular, mantle cell, small lymphocytic, and Hodgkin lymphomas. The evidence, however, for a potent GVL effect in diffuse large-cell lymphoma and Burkitt lymphoma is not convincing. Policies for allografting in lymphoma are proposed on the basis of this evidence. The immunobiology of GVL effects is discussed--in particular, the expression of HLA class I and II and co-stimulatory molecules on lymphomas that influence the generation of alloreactive T cells--together with future directions in immunotherapy that may help to eradicate chemoresistant disease.