The current status of reduced-intensity allogeneic hematopoietic stem cell transplantation for multiple myeloma

Allogeneic hematopoietic cell transplantation for multiple myeloma: A retrospective analysis of the Polish Myeloma Group

PURPOSE

In this multicenter retrospective analysis of the Polish Myeloma Group we assessed the real-life application of allogeneic transplantations (alloHCT) in multiple myeloma (MM) outside clinical trials in Poland.

METHODS

Anonymized clinical data of patients who underwent alloHCT were retrospectively collected from eight transplant centers and analyzed to identify factors affecting the outcome.

RESULTS

Sixty patients (34 males, 26 females) at median age of 45 (22-59) years who received alloHCT between 1993 and 2016 were included. In this group, 16 (27%) patients underwent myeloablative conditioning and 44 (73%) reduced-intensity conditioning alloHCT. Acute graft versus host disease (GvHD) occurred in 27 (45%) patients, while chronic GvHD was diagnosed in 13 (22%) patients. With the median observation time after alloHCT of 10 months, the relapse rate was 38%. Median progression-free survival (PFS) reached 9 months (0-183) while median overall survival (OS) was 23 months (0-183). Main causes of death included disease progression in 16 (43%), infections in 10 (27%), and GvHD in 7 patients (19%). Presence of chronic GvHD was the only factor associated with prolonged PFS (28 vs. 6 months; p = 0.05), however its impact on OS was not statistically significant (73 vs. 8 months; p = 0.09).

CONCLUSIONS

In this relatively small and heterogeneous study we observed that alloHCT was associated with high risk of severe complications, but resulted in long-term survival in a proportion of patients. Decisions on optimal indications and timing of the alloHCT in MM need to be taken in the broader context of reported outcomes including data from large studies.

CTLA4-CD28 chimera gene modification of T cells enhances the therapeutic efficacy of donor lymphocyte infusion for hematological malignancy

Donor lymphocyte infusion (DLI) followed by hematopoietic stem cell transplantation has served as an effective prevention/treatment modality against the relapse of some hematologic tumors, such as chronic myeloid leukemia (CML). However, the therapeutic efficacies of DLI for other types of leukemia, including acute lymphocytic leukemia (ALL), have been limited thus far. Therefore, we examined whether increasing the reactivity of donor T cells by gene modification could enhance the therapeutic efficacy of DLI in a murine model of ALL. When a CTLA4-CD28 chimera gene (CTC28) in which the intracellular signaling domain of CTLA4 was replaced with the CD28 signaling domain was introduced into CD4 and CD8 T cells in DLI, the graft-versus-tumor (GVT) effect was significantly increased. This effect was correlated with an increased expansion of donor CD8 T cells in vivo, and the depletion of CD8 T cells abolished this effect. The CD8 T cell expansion and the enhanced GVT effect were dependent on the transduction of both CD4 and CD8 T cells with CTC28, which emphasizes the role of dual modification in this therapeutic effect. The CTC28-transduced T cells that expanded in vivo also exhibited enhanced functionality. Although the potentiation of the GVT effect mediated by the CTC28 gene modification of T cells was accompanied by an increase of graft-versus-host disease (GVHD), the GVHD was not lethal and was mitigated by treatment with IL-10 gene-modified third-party mesenchymal stem cells. Thus, the combined genetic modification of CD4 and CD8 donor T cells with CTC28 could be a promising strategy for enhancing the therapeutic efficacy of DLI.

Lenalidomide as salvage treatment for multiple myeloma relapsing after allogeneic hematopoietic stem cell transplantation: a report from the French Society of Bone Marrow and Cellular Therapy

Optimal salvage treatment for multiple myeloma relapsing after allogeneic stem cell transplantation remains to be determined. Usually, such patients have been heavily pre-treated and present at relapse with a relatively refractory disease. Immunomodulatory properties of lenalidomide may be beneficial by facilitating a graft-versus-myeloma effect after allogeneic stem cell transplantation. However, the safety of such treatment is still under debate. We conducted a multicenter retrospective study and included 52 myeloma patients receiving lenalidomide alone or in combination with dexamethasone as salvage therapy after allogeneic stem cell transplantation. The first aim was to assess the efficacy and tolerance of this drug. The second aim was to evaluate its potential immunomodulatory effects evaluated on the occurrence of acute graft-versus-host disease under treatment. In this cohort, we show that lenalidomide can induce a high response rate of 83% (including 29% complete response). On lenalidomide therapy, 16 patients (31%) developed or exacerbated an acute graft-versus-host disease, which was the only factor significantly associated with an improved anti-myeloma response. Side effects were mostly reversible, whereas 2 deaths (4%) could be attributed to treatment toxicity and to graft-versus-host disease, respectively. With a median follow up of 16.3 months, the median overall and progression free survival were 30.5 and 18 months, respectively, independently of the occurrence of acute graft-versus-host disease under lenalidomide. Lenalidomide can induce high response rates in myeloma relapsing after allogeneic stem cell transplantation at least in part by triggering an allogeneic anti-myeloma response. Induced graft-versus-host disease has to be balanced against the potential benefit in terms of disease control. Further immunological studies would help us understand lenalidomide immunomodulatory activity in vivo.

Reduced-intensity allogeneic hematopoietic stem cell transplantation for multiple myeloma: a concise review

Reduced-intensity conditioning (RIC) allogeneic hematopoietic stem cell transplantation (HSCT) can result in reliable donor engraftment, relatively low treatment-related mortality, and sustained remissions in the treatment of multiple myeloma. However, substantial cytoreduction pre-allografting is often necessary because of a variable graft-versus-myeloma effect. The use of RIC allogeneic HSCT immediately after autologous HSCT provides a temporal separation between tumor reduction by high-dose chemotherapy and the graft-versus-myeloma effect. There are currently a number of prospective trials attempting to address the issue of whether this strategy leads to decreases in relapse and/or improvement in overall survival as compared with double autologous transplants. Unfortunately, similar to autografting, relapse remains the major cause of treatment failure after RIC allogeneic HSCT. To improve treatment results with allografting, consideration should be given to incorporating immunomodulatory drugs and targeted treatments to enhance pretransplantation remission status, as posttransplantation maintenance therapy, or in combination with donor lymphocyte infusions for refractory or relapsed disease. Studies exploring these strategies are ongoing.

Donor lymphocyte infusion following allogeneic hematopoietic stem cell transplantation

INTRODUCTION

Allogeneic hematopoietic stem cell transplantation (SCT) is the treatment of choice for many malignant hematological disorders. Following recent improvements in non-relapse-related mortality rates, relapse has become the commonest cause of treatment failure. Infusion of donor lymphocytes can potentially enhance immune-mediated antitumor activity and offers a salvage option for some patients. This paper reviews the current literature on the efficacy of this therapeutic strategy.

AREAS COVERED

The biology of adoptive cellular therapy with allogeneic immune cells to treat relapse across a spectrum of diseases in both the full intensity and reduced intensity hematopoietic SCT settings is explored. The review discusses the current limitations of the approach and reviews several new experimental strategies which aim to segregate the desired graft-versus-tumor effect from the deleterious effects of more widespread graft-versus-host reactivity.

EXPERT OPINION

Durable responses to DLI have been noted in chronic myeloid leukemia and responses have also been described in acute leukemia, multiple myeloma and chronic lymphoproliferative disorders. The new challenge in transplantation is to optimize DLI therapy in order to further improve patient outcomes.

Importance of achieving a complete response in multiple myeloma, and the impact of novel agents

The goal of treatment for multiple myeloma (MM) is to improve patients' long-term outcomes. One important factor that has been associated with prolonged progression-free and overall survival is the quality of response to treatment, particularly achievement of a complete response (CR). There is extensive evidence from clinical studies in the transplant setting in first-line MM demonstrating that CR or maximal response post-transplant is significantly associated with prolonged progression-free and overall survival, with some studies demonstrating a similar association with postinduction response. Supportive evidence is also available from studies in the nontransplant and relapsed settings. With the introduction of bortezomib, thalidomide, and lenalidomide, higher rates of CR are being achieved in both first-line and relapsed MM compared with previous chemotherapeutic approaches, thereby potentially improving long-term outcomes. While standard CR by established response criteria has been shown to have differential prognostic impact compared with lesser responses, increasingly sensitive analytic techniques are now being explored to define more stringent degrees of CR or elimination of minimal residual disease (MRD), including multiparameter flow cytometry and polymerase chain reaction. Demonstrating eradication of MRD by these techniques has already been shown to predict for improved outcomes. Here, we review the prognostic significance of achieving CR in MM and highlight the importance of CR as an increasingly realizable goal at all stages of treatment. We discuss clinical management issues and provide recommendations relevant to practicing oncologists, such as the routine use of sensitive techniques for assessment of disease status to inform evidence-based decisions on optimal patient management.

Staged heart transplantation and chemotherapy as a treatment option in patients with severe cardiac light-chain amyloidosis

AIMS

The prognosis of advanced cardiac light-chain amyloidosis is poor. Heart transplantation might enable causative therapy and ultimately improve prognosis.

METHODS AND RESULTS

Nineteen patients with cardiac amyloidosis but no obvious involvement of other organs were scheduled for heart transplantation. Four to 6 months later, high-dose melphalan chemotherapy and autologous stem cell transplantation (HDM-ASCT) was planned in patients not in complete remission. Seven of nineteen patients died while waiting for heart transplantation. The remaining 12 patients (complete remission, n = 4) underwent surgery. Chemotherapy in patients not in complete remission consisted of HDM-ASCT (n = 5/12; subsequent complete remission, n = 2; partial remission, n = 3) or melphalan-prednisolone (partial remission, n = 1). Two of twelve patients were ineligible for any chemotherapy. Three of twelve patients died [423.5 (105-2131) days] from progressive disease, relapse, or sepsis. The 1- and 3-year survival rates were 83 and 83%, respectively, similar to those of patients undergoing heart transplantation for standard indications. Corresponding survival rates stratified by haematological response were 100 and 100% for complete remission (partial remission, 100 and 100%; progressive disease, 0 and 0%).

CONCLUSION

Heart transplantation in advanced cardiac amyloidosis is a promising approach to interrupting the vicious circle of ineligibility for potential curative chemotherapeutic treatment and extremely poor prognosis of cardiac amyloidosis without chemotherapy. Highly urgent heart transplantation combined with subsequent HDM-ASCT appears to offer a successful treatment option to improve the poor outcome of cardiac amyloidosis. However, it should be restricted to highly selected patients in specialized centres.

Thymocyte expansion and maturation: crosstalk of CD44v6 on thymocytes and panCD44 on stroma cells

Re-acquisition of immunocompetence after allogeneic bone marrow cell (BMC) transplantation depends on intrathymic maturation of the allogeneic T progenitor cells. We recently reported that CD44 promotes progenitor homing into the thymus and T-cell maturation and now elucidate the molecular mechanisms of CD44-supported thymocyte maturation. Lethally irradiated, tumor-bearing mice, allogeneically reconstituted with T-cell-depleted BMC and a small number of common lymphoid progenitor 2 cells (CLP2) from transgenic (TG) mice, that express ratCD44v4-v7 under the Thy1 promoter, showed accelerated immunocompetent T-cell recovery compared with mice reconstituted with non-transgenic (NTG) CLP2. In addition, graft-versus-host disease was strongly reduced after tumor vaccination. TG, but not NTG double-negative (DN) thymocytes showed high proliferative potential, accompanied by constitutive association of lck with CD44. Importantly, when thymocyte adhesion was strengthened by anti-CD44, co-cultures of DN thymocytes with thymic stroma supported DN thymocyte maturation. The close contact between DN thymocytes and thymic stroma promoted persisting activation of lck and ERK1/2, particularly in CD44v6(+) DN thymocytes. Thus, intrathymic T-cell maturation in allogeneically reconstituted, leukemia-bearing hosts can be considerably accelerated by high CD44v6 expression in early thymocytes, in which proliferation-supporting signals are initiated by a crosstalk between CD44v6 on thymocytes and panCD44 on the thymic stroma.

Development of tumor-reactive T cells after nonmyeloablative allogeneic hematopoietic stem cell transplant for chronic lymphocytic leukemia

PURPOSE

Allogeneic nonmyeloablative hematopoietic stem cell transplant (NM-HSCT) can result in durable remission of chronic lymphocytic leukemia (CLL). It is thought that the efficacy of NM-HSCT is mediated by recognition of tumor cells by T cells in the donor stem cell graft. We evaluated the development of CTLs specific for CLL after NM-HSCT to determine if their presence correlated with antitumor efficacy.

EXPERIMENTAL DESIGN

Peripheral blood mononuclear cells obtained from 12 transplant recipients at intervals after NM-HSCT were stimulated in vitro with CLL cells. Polyclonal T-cell lines and CD8(+) T-cell clones were derived from these cultures and evaluated for lysis of donor and recipient target cells including CLL. The presence and specificity of responses was correlated with clinical outcomes.

RESULTS

Eight of the 12 patients achieved remission or a major antitumor response and all 8 developed CD8(+) and CD4(+) T cells specific for antigens expressed by CLL. A clonal analysis of the CD8(+) T-cell response identified T cells specific for multiple minor histocompatibility (H) antigens expressed on CLL in six of the responding patients. A significant fraction of the CD8(+) T-cell response in some patients was also directed against nonshared tumor-specific antigens. By contrast, CLL-reactive T cells were not detected in the four patients who had persistent CLL after NM-HSCT, despite the development of graft-versus-host disease.

CONCLUSIONS

The development of a diverse T-cell response specific for minor H and tumor-associated antigens expressed by CLL predicts an effective graft-versus-leukemia response after NM-HSCT.

Modern treatment options for elderly patients with multiple myeloma

Multiple myeloma, an incurable malignancy of plasma cells, is a disease of the elderly. In younger patients, significant therapeutic progress has been achieved, but survival outcomes remain unacceptably low in older adults with multiple myeloma. Diverse factors, including comorbidity, performance status, decreased physiologic reserve, and potential undertreatment, contribute to these poor outcomes. Unfortunately, many clinical trials are designed to exclude elderly patients with coexisting diseases, so only limited data are available and no guidelines exist on how to treat this challenging and growing myeloma population. A broader range of therapeutic options has become available within the last few years, including chemotherapy with either established or newly available drugs, immunomodulators, and high-dose treatment with stem cell support (autologous as well as allogeneic). In this review, we discuss the data available from clinical trials investigating antineoplastic treatment of elderly multiple myeloma patients.

Stem-Cell Transplantation for Multiple Myeloma in the Era of Novel Drugs

The treatment of multiple myeloma (MM) is changing rapidly. During the last 10 years, higher rates of complete response (CR) and prolonged progression-free and overall survival have been seen with high-dose chemotherapy plus autologous stem-cell transplantation (HDT-ASCT). Achievement of CR and good partial response have been shown to be key prognostic factors for prolonged survival, with eradication of minimal residual disease seeming crucial to long-term disease-free survival. Until recently, high rates of CR and other major responses were primarily seen with HDT-ASCT, but insights into the biology of MM have led to the development and approval of new drugs with significant activity, and new induction regimens based on these novel agents are offering improved responses. Thalidomide, bortezomib, and lenalidomide have been combined with corticosteroids, alkylators, and anthracyclines in front-line MM treatment. Phase II studies have indicated that high rates of response and CR may be achieved. The substantial activity seen with these new drug combinations has prompted a re-examination of the role of SCT in MM treatment. Will achievement of major responses with these new regimens translate into improved survival after consolidation with transplantation? Will these improved induction regimens reduce the need for tandem transplantation, or does achievement of CR obviate the need for front-line transplantation altogether? To help address these questions, randomized trials are needed, as well as tests with improved sensitivity to better define depth of remission.

Hematopoietic Stem Cell Transplantation in Multiple Myeloma

High-dose therapy and autologous hematopoietic stem cell transplantation are standard early treatment of patients with multiple myeloma. Tandem transplantation appears to provide additional benefit, particularly in patients with limited response to initial transplantation. Myeloablative allogeneic transplantation provides the only potential for cure, but has been largely abandoned because of high mortality rates. Newer and better induction regimens, rigorous analysis of results with autologous and allogeneic transplantation, and the development of risk-adapted stratification provide the impetus for this critical evaluation of the role of hematopoietic stem cell transplantation in multiple myeloma.

Results of the EBMT activity survey 2005 on haematopoietic stem cell transplantation: focus on increasing use of unrelated donors

This EBMT activity report documents the haematopoietic stem cell transplantation (HSCT) activity in Europe in 2005. It provides numbers of HSCT by indication, donor type and stem cell source, lists the new practice of planned double transplants with allogeneic after autologous HSCT and concentrates on the increasing role of unrelated transplants over the last years. In 2005, there were 24,168 first HSCT, 8890 allogeneic (37%), 15,278 autologous (63%) and 3773 additional re- or multiple transplants reported from 597 centres in 43 participating countries. Main indications were leukaemias (7404 (31%; 82% allogeneic)); lymphomas (13,825 (57%; 89% autologous)); solid tumours (1655 (7%; 92% autologous)) and non-malignant disorders (1131 (5%; 93% allogeneic)). A total of 671 planned allogeneic after autologous HSCT were reported; the majority for myeloma (52%), lymphoma (28%) and acute myeloid leukaemia (11%). Compared to 2004, there was a 20% increase in allogeneic HSCT; numbers of autologous HSCT remained constant. The most noticeable increase was in unrelated HSCT, which comprise 41% of all allogeneic HSCT. Unrelated HSCT were preferentially performed for leukaemias and in countries with high income according to World Bank criteria. These data illustrate the current experience in Europe and form the basis for patient counselling and decisions making at health care institutions.

Disease relapse after haematopoietic stem cell transplantation: Risk factors and treatment

Disease relapse is the commonest cause of treatment failure after allogeneic haematopoietic stem-cell transplantation. Adoptive immunotherapy based on donor lymphocyte infusions (DLI) has a prominent role in the management of disease recurrence. Although the highest remission rates are achieved in chronic myeloid leukaemia (CML), encouraging results have also been reported in chronic lymphoproliferative disorders. However, the experience of DLI in CML is not necessarily applicable to the management of lymphoproliferative diseases because of the heterogeneity of the conditioning regimens used in chronic lymphoid malignancies. We will review the role of DLI for different disease types in the context of conventional and reduced-intensity conditioning regimens. The factors influencing response and graft-versus-host disease as well as the optimal cell dose will be discussed. Finally, we will describe the main avenues currently being explored to improve the selectivity and efficacy of DLI.

Long-term outcome of myeloablative allogeneic stem cell transplantation for multiple myeloma

Allogeneic stem cell transplantation (alloSCT) has been used in the hopes of harnessing the curative potential of the graft-versus-myeloma effect. This study examines the long-term outcomes of a large cohort of patients with myeloma who were treated with myeloablative alloSCT at a single center. Comparisons are made with those who were treated with autologous stem cell transplantation (ASCT). Between January 1989 and February 2002, 158 patients age<or=55 years underwent SCT for myeloma. Seventy-two patients underwent myeloablative alloSCT (58 related; 14 unrelated), whereas 86 patients underwent ASCT. Most patients received single-agent high dose dexamethasone or VAD (vincristine, adriamycin, dexamethasone) therapy pre-SCT. Conditioning regimens were melphalan-based for all ASCT patients, whereas the alloSCT patients received melphalan-based (70%), total-body irradiation (TBI)-based (18%), or other (13%). Patients who underwent alloSCT were younger, had a higher Durie-Salmon stage disease, and a shorter median time from diagnosis to transplant. Myeloma subtypes were similar between groups. Other pre-SCT (BMT) characteristics were similar except that ASCT patients had a higher proportion of cases that received palliative radiotherapy pre-SCT. Disease response pre-SCT was similar. At last follow-up, 61 of 158 patients are alive with a median follow-up of 88.4 months (range: 35.5-208.5). The overall survival (OS) of the alloSCT cohort was 48.1% at 5 years and 39.9% at 10 years compared to 46.2% at 5 years and 30.8% at 10 years for the ASCT cohort (P=.94). The event-free survival of the alloSCT cohort was 33.3% at 5 years and 31.4% at 10 years compared to 32.9% and 15.2%for the ASCT cohort (P=.64). Treatment-related mortality (TRM) at 1 year was 22% for the alloSCT cohort and 14% in the ASCT cohort (P=.21). Cumulative incidence of grade II-IV acute graft-versus-host disease (aGVHD) was 72% and the cumulative incidence of chronic GVHD (cGVHD) was 68% at 2 years. Neither aGVHD nor cGVHD had an influence on OS or event-free survival, although 5 of 14 patients who have received donor lymphocyte infusions (DLI) have had disease response. The risk of relapse was reduced in those who developed aGVHD (P=.02) but not cGVHD (P=.23). In conclusion, although there are patient who are alive without disease>10 years post myeloablative alloSCT, similarly there are long-term survivors post-ASCT. Myeloablative alloSCT should not be considered standard treatment, and should only be considered in the context of a clinical trial.